Zivan charger and Deka gel batteries

[David Peichel]

I have a Zivan NG3 charger that I'm about to send back to Elcon for
programming. I've been talking with them about how they will program it for
my Deka Dominator group 31 gel 12V lead acid batteries. Looks like it will
use a 3 phase charge: The first phase is at constant power while the
voltage climbs to 14.1V per battery. The second phase holds this voltage
while the current decays to about 2A. The third phase then pulses the stack
5 seconds on and 5 seconds off with a current of 3.5A, during which the
voltage is allowed to climb to some level above 14.1V. The third phase
continues until the dV/dt between pulses drops to below 10mV (per cell?) or
until some time limit for phase 3 is reached (6 hours).

Of course, I've very nervous about how this charger will exceed the maximum
voltage in the Deka gel charging specifications. This is my first conversion
and I don't want to be another person who murders their first battery pack.
They claimed that for traction batteries, this is okay to do and will not
shorten the life of the batteries (but couldn't explain why). I'm
speculating that the goal was to trade off a little bit of over-voltaging to
help keep the batteries in the stack better balanced, since undercharging
can also be a problem in the long run. I did a little research and found
some stuff about how a small amount of gassing will recombine and not be a
problem, and someone else claiming a trickle current of 1/100th the power
rating is okay (which would be 1 A for this battery, which we are pretty
close to here given the 50% duty cycling of the 3.5A).

http://vrlabattery.onesite.com/blog/2007/12/20/a_comparision_of_agm_and_gel_
sealed_lead_acid_batt

http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/
33539-12v-gel-lead-acid-charger-tweaking-help-needed.html

So their approach may be more or less okay if you don't mind trading off a
little cycle life for balancing the battery stack. If this is true, I wish I
could quantify it. I would appreciate any advice anyone can give me on
whether I will be okay with this type of charging profile on a sealed gel
battery for an EV. Unless there is some solid experience or data on this
being okay, I'm feeling like I need to switch to a charger that will be a
little more judicious about limiting the voltage. I asked Elcon if they
could change to profile to give me what I wanted, but they did not want to
be responsible for a charging profile other than what they are offering.

Thanks!
Dave

[Roger Stockton]

David Peichel wrote:

> The first phase is at constant power while the
> voltage climbs to 14.1V per battery. The second phase holds
> this voltage while the current decays to about 2A. The third
> phase then pulses the stack
> 5 seconds on and 5 seconds off with a current of 3.5A, during
> which the voltage is allowed to climb to some level above
> 14.1V. The third phase continues until the dV/dt between
> pulses drops to below 10mV (per cell?) or until some time
> limit for phase 3 is reached (6 hours).
>
> Of course, I've very nervous about how this charger will
> exceed the maximum voltage in the Deka gel charging
> specifications.

This type of charge profile should be just fine. It is not exceeding the maximum voltage in the DEKA gel charging specs. DEKA specs something like a max of 30A/100Ah until the voltage ia about 2.35V/cell (14.1V/12V battery), then hold that voltage until the current tapers to something like 1.5A/100Ah, then hold about 1.5A/100Ah for 2-4hr depending on how deeply discharged the battery was. The voltage in this last step is allowed to rise considerably above the 14.1V level.

I would be more concerned with ensuring that you get the optional temperature probe for your Zivan and attach it securely to one of the center modules in the pack so that the 14.1V charge voltage is properly compensated for the actual battery temperature.

What is your pack voltage and/or what is the maximum current you plan on drawing from the batteries? Gels don't take particularly well to high discharge rates, and you might find this pack doesn't last as long as you'd hoped if you call on it to deliver 400-500A routinely.

Cheers,

Roger.

[davep]

Where do you find these charging specs? The only thing I found on the Deka
website said never to exceed 14.1V (or the temp adjusted version of this)
and doesn't mention anything about the low current holding to finish the
charge. Based on what you have, I agree I could be okay, although I don't
understand why they feel they need to pulse the current in the final phase.
Is there some benefit to pulsing? I have the temp probe and will make sure
to locate it in the warmed spot I can find.

I have the Azure Dynamics AC setup for my Geo Metro, and I'm doing a 156V
pack, so my max current will be 200 A. Sounds like these gels worked well
for the Solectria Forces...

Thanks for the help!
Dave


Roger Stockton wrote:
>
> This type of charge profile should be just fine. It is not exceeding the
> maximum voltage in the DEKA gel charging specs. DEKA specs something like
> a max of 30A/100Ah until the voltage ia about 2.35V/cell (14.1V/12V
> battery), then hold that voltage until the current tapers to something
> like 1.5A/100Ah, then hold about 1.5A/100Ah for 2-4hr depending on how
> deeply discharged the battery was. The voltage in this last step is
> allowed to rise considerably above the 14.1V level.
>
> What is your pack voltage and/or what is the maximum current you plan on
> drawing from the batteries? Gels don't take particularly well to high
> discharge rates, and you might find this pack doesn't last as long as
> you'd hoped if you call on it to deliver 400-500A routinely.
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

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[Peter VanDerWal]

A little background (as I understand it) on VRLA batteries (Gel Cells,
AGMs, etc.)

During the final charge phase, as well as during overcharge(equalization),
a significant amount of your charge current ends up hydrolyzing the water
in the battery instead of charging the plates. This causes oxygen and
hydrogen to build up in the cells and create preassure. If the peassure
gets to high, the cells vent. The cells have a built in catalyst
(platinum usually) to recombine the H2 and O2 into water, but it can only
do this at a fairly slow rate so current during this phase needs to be
limited to a low level.

The problem with this low level current is that most of the current
actually ends up cracking the water, leaving little if any to charge the
plates. This is where the high current pulses come in, they are strong
enough to ensure the plates gets some extra charging, but are limited in
duration to give the catalyst time to recombine the H2 and O2 between
pulses and keep the cells from venting.

This is an overly simplistic explanation, and I might be wrong on a couple
minor details, but I think it covers the basics.

>
> Where do you find these charging specs? The only thing I found on the
> Deka
> website said never to exceed 14.1V (or the temp adjusted version of this)
> and doesn't mention anything about the low current holding to finish the
> charge. Based on what you have, I agree I could be okay, although I don't
> understand why they feel they need to pulse the current in the final
> phase.
> Is there some benefit to pulsing? I have the temp probe and will make
> sure
> to locate it in the warmed spot I can find.
>
> I have the Azure Dynamics AC setup for my Geo Metro, and I'm doing a 156V
> pack, so my max current will be 200 A. Sounds like these gels worked well
> for the Solectria Forces...
>
> Thanks for the help!
> Dave
>
>
> Roger Stockton wrote:
>>
>> This type of charge profile should be just fine. It is not exceeding
>> the
>> maximum voltage in the DEKA gel charging specs. DEKA specs something
>> like
>> a max of 30A/100Ah until the voltage ia about 2.35V/cell (14.1V/12V
>> battery), then hold that voltage until the current tapers to something
>> like 1.5A/100Ah, then hold about 1.5A/100Ah for 2-4hr depending on how
>> deeply discharged the battery was. The voltage in this last step is
>> allowed to rise considerably above the 14.1V level.
>>
>> What is your pack voltage and/or what is the maximum current you plan on
>> drawing from the batteries? Gels don't take particularly well to high
>> discharge rates, and you might find this pack doesn't last as long as
>> you'd hoped if you call on it to deliver 400-500A routinely.
>>
>> Cheers,
>>
>> Roger.
>>
>> _______________________________________________
>> For subscription options, see
>> http://lists.sjsu.edu/mailman/listinfo/ev
>>
>>
>
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> View this message in context:
> http://www.nabble.com/Zivan-charger-and-Deka-gel-batteries-tp16294212p16301162.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

[Roger Stockton]

davep wrote:

> Where do you find these charging specs?

>From East Penn/DEKA themselves. I work for a battery charger manufacturer and have implemented charge algorithms for DEKA batteries in consultation with DEKA's engineers.

The 'gel battery charging' spec I have in front of me states:

Bulk I1: maintain current <= 30A/100Ah C/20 (constant power or taper charge also permitted). End when voltage V1 = 2.30-2.35V/cell @ 20C. Stop if more than 1.2 * DOD (Ah)/avg. current (A) hours elapses. (That is, of you removed 100Ah and are charging at 10A, then stop if the bulk phase exceeds (1.2*100)/10 = 12 hours.)

Absorption V1: maintain 2.30-2.35V/cell @ 20C until current drops by less than 0.10A over a 1hr period, or for a maximum of 12hrs. Then, advance to optional float stage V2.

OR:

Absorption V1: maintain 2.30-2.35V/cell @ 20C until current drops to I2 = 1 to 1.5A per 100Ah C/20, or for a maximum of 6hrs. Then advance to optional accelerated finish stage I2.

Optional Finish Stage I2: maintain current 1 to 1.5A per 100Ah C/20 for 1 to 4 hrs based on Ah accumulated in the first 2 stages. Halt or advance to optional float stage V2 if votlage exceeds 2.80V/cell.

Optional float Stage V2: maintain 2.25V/cell at 20C

Voltages are compensated by 0.005V/cell per degree C from 20C.

The recommended profile for DEKA AGMs is identical other than:

- V1 = 2.40-2.43V/cell @ 20C

- I2 = 1 to 2A per 100Ah C/20.

> The only thing I
> found on the Deka website said never to exceed 14.1V (or the
> temp adjusted version of this) and doesn't mention anything
> about the low current holding to finish the charge. Based on
> what you have, I agree I could be okay, although I don't
> understand why they feel they need to pulse the current in
> the final phase.
> Is there some benefit to pulsing? I have the temp probe and
> will make sure to locate it in the warmed spot I can find.

My take on pulsing the finish current is that this is a means of accounting for the fact that when you charge a long string of batteries, some will be above the average voltage while the charger can only see the pack total (= avg. * # of modules).

The higher the voltage gets during finish, the less efficient the recombination process is, so if constant current is applied and a module in the string stays at elevated voltage long enough, it may vent even if the charge current is "low".

Turning the charge current off periodically allows the voltage to relax and recombination efficiency to increase such that the recombination may "catch up" so that venting is avoided.

Since the current is only applied for a fraction of the time, a higher current can be used so that while the average is "low", the relatively higher current applied during the on-portion may be more effective a charging more resistive areas of the plates.

> I have the Azure Dynamics AC setup for my Geo Metro, and I'm
> doing a 156V pack, so my max current will be 200 A. Sounds
> like these gels worked well for the Solectria Forces...

Yep; you should be OK. Your group 31's are even a bit larger in capacity than the batteries used in the Forces so will better tolerate the same sort of peak discharge rates.

Cheers,

Roger.

[Peter VanDerWal]

> I have the Azure Dynamics AC setup for my Geo Metro, and I'm
> doing a 156V pack, so my max current will be 200 A.

Expect dismal performance in acceleration. This is even less power
available than my (relatively small and light) truck has and it is a slug.

My truck: mid 80's Toyota pickup (on the outside),
3200 lbs,
120V @ 350 max battery amps.
0-60 mph in 1 minute 20 seconds

[Bob Rice]

----- Original Message -----
From: "Peter VanDerWal" <evdl-xlAVAfeI+***@public.gmane.org>
To: "Electric Vehicle Discussion List" <ev-UWgVIey+***@public.gmane.org>
Sent: Wednesday, March 26, 2008 8:27 AM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


>> I have the Azure Dynamics AC setup for my Geo Metro, and I'm
>> doing a 156V pack, so my max current will be 200 A.
>
> Expect dismal performance in acceleration. This is even less power
> available than my (relatively small and light) truck has and it is a slug.
>
> My truck: mid 80's Toyota pickup (on the outside),
> 3200 lbs,
> 120V @ 350 max battery amps.
> 0-60 mph in 1 minute 20 seconds

> Ha! I THOUGHT my Rabbit was slow! 0 to 80 in ONE minute in the Acela
> Express by Amtrak! Pedal to the mettle start! Dry Rail. With about 330
> hostages, er, I mean ,passengers aboard! Gotta time the Sentra,
> ........dusting off the hourglass!

Seeya in the slo lane!

Bob
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev

[Mark Grasser]

> My truck: mid 80's Toyota pickup (on the outside),
> 3200 lbs,
> 120V @ 350 max battery amps.
> 0-60 mph in 1 minute 20 seconds

> Ha! I THOUGHT my Rabbit was slow! 0 to 80 in ONE minute in the Acela
> Express by Amtrak! Pedal to the mettle start! Dry Rail. With about 330
> hostages, er, I mean ,passengers aboard! Gotta time the Sentra,
> ........dusting off the hourglass!

Didn't I see something about someone figuring out how to add a bypass
contactor to get full current? Add a micro switch to the throttle for full
acceleration. It would act like the old automatic kick down switch (for us
older drivers)


Mark Grasser
Balyntec
Marine Products, LLC
828-581-4601
mark.grasser-PsZFI1cOZt9Wk0Htik3J/***@public.gmane.org

[Stephen West]

> My truck: mid 80's Toyota pickup (on the outside),
> 3200 lbs,
> 120V @ 350 max battery amps.
> 0-60 mph in 1 minute 20 seconds

Hmmm, 3200 lbs @ 60 mph is around 523kJ of KE. Spread over 80 seconds that's
an average of 6.5kW delivered (ignoring drag). That's significantly less
than 42kW of battery power. Any idea where all the power is going?

Steve

[Peter VanDerWal]

>> My truck: mid 80's Toyota pickup (on the outside),
>> 3200 lbs,
>> 120V @ 350 max battery amps.
>> 0-60 mph in 1 minute 20 seconds
>
> Hmmm, 3200 lbs @ 60 mph is around 523kJ of KE. Spread over 80 seconds
> that's
> an average of 6.5kW delivered (ignoring drag). That's significantly less
> than 42kW of battery power. Any idea where all the power is going?
>
> Steve
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

Voltage sag accounts for quite a bit of it. Maximum usuable battery power
is only about 35kw. Assuming standard losses through the motor & drive
train, there is only about 25-26 kw available at the wheels.

Steady cruising power requirements at 55-60 mph has been approx 15-20 kw...

Looks like the numbers work out to me.

[EVDL Administrator]

On 26 Mar 2008 at 6:27, Peter VanDerWal wrote:

> Expect dismal performance in acceleration. This is even less power
> available than my (relatively small and light) truck has and it is a slug.

The Solectria Force used this exact combination, with a custom single-speed
transaxle. It was no tire shredder, that's for darn sure, but most Force
owners will tell you it had/has reasonable enough pep around town. (Of
course, one person's "reasonable" can be another person's "slug." ;-)

Now, on the highway, that's another story. Getting to 60mph can be an
excruciating wait, especially when a semi is bearing down on you.

However, I suspect that if you've retained the factory Geo transaxle instead
of using Solectria's single-speed transaxle, it should help with
acceleration. I haven't driven such a car, though.

David Roden - Akron, Ohio, USA
EVDL Administrator

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[EVDL Administrator]

I charge Deka Dominators to 14.3 volts and get excellent service. I don't
recommend exceeding that value under any circumstances.

I think East Penn will void your warranty if they find that you've exceeded
14.1 volts, their spec. Mine are long out of warranty. I've been using 6
of them in my Elec-Trak tractor for 10 years now. Still going strong.

A friend of mine used to have a Zivan charger. He was never able to get a
profile in it that would not murder his (flooded!) batteries. He ran into
the same problem - the US distributor would not set the profile the way he
wanted it.

Victor's Brusa chargers are completely user-programmable, very flexible,
extraordinary quality, made in Switzerland. They're pricey, but maybe not
when you consider the quality level and features you get. They do have one
relatively low-cost model which might meet your needs. Ask Victor.

If you want something cheaper and your system voltage is moderate, I suggest
you talk to Roger about a Delta-Q charger (designed in Canada and made in
China). I think they have a 96v model, though it's not listed in the spec
sheet. You might be able to use two lower voltage chargers, but then you'd
probably be getting closer to the Brusa's cost.

Russco has an IUI option for their chargers. I think they're strictly
analog control, but Russ could tell you more. Note that unlike the Brusa
and Delta-Q, Russco chargers are not fully isolated, but they do have a
built-in GFI.

East Penn's quality control is unusually good. Their gel batteries are very
consistent, and usually do well without individual module regulators.

David Roden
EVDL Administrator
http://www.evdl.org/

[Roger Stockton]

EVDL Administrator wrote:

> If you want something cheaper and your system voltage is
> moderate, I suggest you talk to Roger about a Delta-Q charger
> (designed in Canada and made in China). I think they have a
> 96v model, though it's not listed in the spec sheet.

This is correct, I believe that both 84V and 96V models are now available even though they are not yet listed on the website. I suggest checking with Randy at Canadian Electric Vehicles (www.canev.com> can supply if one is interested in a Delta-Q charger.

Cheers,

Roger.

[Deanne Mott]

I recently received a 96V Delta-Q from Canadian EV - email Randy there
if you are interested. I have not installed it yet but will be
shortly.

De

On Wed, Mar 26, 2008 at 3:20 PM, Roger Stockton <rstockton-***@public.gmane.org> wrote:
> EVDL Administrator wrote:
>
> > If you want something cheaper and your system voltage is
> > moderate, I suggest you talk to Roger about a Delta-Q charger
> > (designed in Canada and made in China). I think they have a
> > 96v model, though it's not listed in the spec sheet.
>
> This is correct, I believe that both 84V and 96V models are now available even though they are not yet listed on the website. I suggest checking with Randy at Canadian Electric Vehicles (www.canev.com> can supply if one is interested in a Delta-Q charger.
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

[k***@public.gmane.org]

That profile is for AGM batteries. The final constant current (CC)
pulse charge is for the recombinant process that AGM’s employ. Few
data sheets explain this very well. For example the Optima data sheet
states, "...When current falls below amp, finish with 2 amp constant
current for 1 hour." The constant current implies no voltage limit.
However, during the "bulk" charging phase the absolute maximum voltage
is 15.6 volts.

I have been using the Zivan NG3 with that same profile on Optima Blue
Tops and Odyssey PC1200s with excellent results. I have, however, also
added regulators designed to operate during the pulse phase which
really helps keep them balanced. (
http://www.hotjuiceelectric.com/product_beq1.html )

All this may be completely moot, however, since your batteries are gel
instead of AGM. I assume you informed Elcon that the batteries are gel
instead of AGM? I do not have enough experience with gels to know if
they require a recombinant phase, but I did notice the Deka Dominator
data sheet makes no mention of a final CC phase.

Ken




-----Original Message-----
From: David Peichel <***@peichel.com>
To: ***@lists.sjsu.edu
Sent: Tue, 25 Mar 2008 8:44 pm
Subject: [EVDL] Zivan charger and Deka gel batteries



I have a Zivan NG3 charger that I'm about to send back to Elcon for
programming. I've been talking with them about how they will program
it for
my Deka Dominator group 31 gel 12V lead acid batteries. Looks like it
will
use a 3 phase charge: The first phase is at constant power while the
voltage climbs to 14.1V per battery. The second phase holds this
voltage
while the current decays to about 2A. The third phase then pulses the
stack
5 seconds on and 5 seconds off with a current of 3.5A, during which the
voltage is allowed to climb to some level above 14.1V. The third phase
continues until the dV/dt between pulses drops to below 10mV (per
cell?) or
until some time limit for phase 3 is reached (6 hours).

Of course, I've very nervous about how this charger will exceed the
maximum
voltage in the Deka gel charging specifications. This is my first
conversion
and I don't want to be another person who murders their first battery
pack.
They claimed that for traction batteries, this is okay to do and will
not
shorten the life of the batteries (but couldn't explain why). I'm
speculating that the goal was to trade off a little bit of
over-voltaging to
help keep the batteries in the stack better balanced, since
undercharging
can also be a problem in the long run. I did a little research and
found
some stuff about how a small amount of gassing will recombine and not
be a
problem, and someone else claiming a trickle current of 1/100th the
power
rating is okay (which would be 1 A for this battery, which we are pretty
close to here given the 50% duty cycling of the 3.5A).

http://vrlabattery.onesite.com/blog/2007/12/20/a_comparision_of_agm_and_gel_
sealed_lead_acid_batt

http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/
33539-12v-gel-lead-acid-charger-tweaking-help-needed.html

So their approach may be more or less okay if you don't mind trading
off a
little cycle life for balancing the battery stack. If this is true, I
wish I
could quantify it. I would appreciate any advice anyone can give me on
whether I will be okay with this type of charging profile on a sealed
gel
battery for an EV. Unless there is some solid experience or data on this
being okay, I'm feeling like I need to switch to a charger that will be
a
little more judicious about limiting the voltage. I asked Elcon if they
could change to profile to give me what I wanted, but they did not want
to
be responsible for a charging profile other than what they are offering.

Thanks!
Dave

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


_______________________________________________
For subscription options, see

[Richard Acuti]

I agree with Ken. Build some batt regs to keep them equal and prevent them from reaching a voltage that causes them to vent. And definitely get the temp probe.

I have the NG3 and I've heard some stories about them cooking batteries but I've had good luck with mine over the last year. My batteries died because I hammered the dog crap out of them during driving, especially in the beginning months.

I do intend to buy the temp probe thought because in the hottest and coldest months, I think the charger could use the extra information to really optimize the profile. During the most extreme months, I was probably over and under charging a little. For sealed batteries, you really don't want them to overcharge.

If you take those precautions, I think you'll be ok but I'm not the expert. :)





From: David Peichel <dave-***@public.gmane.org>To: ev-UWgVIey+Hux8r6yUnPfhzIgTZbYi8/***@public.gmane.org: Tue, 25 Mar 2008 8:44 pmSubject: [EVDL] Zivan charger and Deka gel batteries I have a Zivan NG3 charger that I'm about to send back to Elcon forprogramming. I've been talking with them about how they will program it formy Deka Dominator group 31 gel 12V lead acid batteries....<snip>



Rich A.
Maryland
http://www.austinev.org/evalbum/371.html
_________________________________________________________________
Test your Star IQ
http://club.live.com/red_carpet_reveal.aspx?icid=redcarpet_HMTAGMAR

[Lee Hart]

From: David Peichel
> I have a Zivan NG3 charger that I'm about to send back to Elcon for
> programming. I've been talking with them about how they will program
> it for my Deka Dominator group 31 gel 12V lead acid batteries. Looks
> like it will use a 3 phase charge: The first phase is at constant power
> while the voltage climbs to 14.1V per battery. The second phase holds
> this voltage while the current decays to about 2A. The third phase then
> pulses the stack 5 seconds on and 5 seconds off with a current of 3.5A,
> during which the voltage is allowed to climb to some level above 14.1V.
> The third phase continues until the dV/dt between pulses drops to below
> 10mV (per cell?) or until some time limit for phase 3 is reached (6
> hours).

That third phase is unusual, but not necessarily a bad algorithm. I don't know how the batteries will react to that 3.5amp 5-sec on/off routine. It sounds like something done more for the charger's benefit than for the battery's.

> Of course, I've very nervous about how this charger will exceed the
> maximum voltage in the Deka gel charging specifications. This is my
> first conversion and I don't want to be another person who murders
> their first battery pack.

Deka gels have the potential to last a very long time, and Deka seems to know what they're talking about on charging them. Their recommendations are pretty conservative, which leads to slow charging; but seems to do well for battery life.

> So their approach may be more or less okay if you don't mind trading
> off a little cycle life for balancing the battery stack.

That would be my guess. Elcon's algorithm may also increase capacity per cycle, but reduce the total number of cycles.

> I asked Elcon if they could change to profile to give me what I wanted,
> but they did not want to be responsible for a charging profile other
> than what they are offering.

My guess is that they will not take responsibility for *anything* that happens to your batteries, no matter what profile they provide. The warranty (if any) comes from your battery vendor. So, I would suggest following whatever profile the *battery* maker wants if you expect them to honor your warranty.



--
Those who say it cannot be done should not interrupt the one who is
doing it. -- Chinese proverb
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

[Al Lococo]

After reading all the comments on NG3 charging, I am wondering if my
approach to this problem is sound. Here is my experience. I am interested
in any suggestions.

I have an NG3 120Volt on board with 12 120 pound UB4D AGM batteries. My
charger was exceeding the battery manufacturers recommendation (14.1 -
14.4). I don't know how high it would go, I pulled the plug at 175 volts.
in stage one, it was supposed to stop at 171 volts. I turned the voltage
down to 168 volts as a stage one terminating voltage.

I decided my battery pack is worth more than the charger. I took the cover
off and turned town the voltage.

I then found stage three was peaking its pulses at 180 volts. I am pulling
the plug early in stage three.

I use eleven battery Cheq equalizers. I prefer this to overcharging to
equalize the batteries. I don't know if they will work with 31 batteries?
I know of one person using them with 24 batteries, but they say 12 batteries
is best.

In the end you are the one who, I believe is responsible for your battery
life. I wish I could program the charger myself. I would like it to stop
after stage two is finished. I am thinking about a clock where I can set
the time. I find, I need about three hours of charge for every 10 miles.

http://www.lococo.org/Electric%20Truck/99%20Ranger.htm

You can search the document for NG3 and/or battery to find info about my
experience.

I know the Deka Dominator Gels, are designed to vent, so you may be OK.
Most of the posts seem to agree on that. Check your individual voltages.
Do something to keep therm in line with each other. Whether it is
equalizers, controlled pulsed over charge or individual battery charged with
a six volt charger.

Cheers,
Al Lococo

----- Original Message -----
From: "David Peichel" <dave-***@public.gmane.org>
To: <ev-UWgVIey+***@public.gmane.org>
Sent: Tuesday, March 25, 2008 9:44 PM
Subject: [EVDL] Zivan charger and Deka gel batteries


>
> I have a Zivan NG3 charger that I'm about to send back to Elcon for
> programming. I've been talking with them about how they will program it
> for
> my Deka Dominator group 31 gel 12V lead acid batteries. Looks like it
> will
> use a 3 phase charge: The first phase is at constant power while the
> voltage climbs to 14.1V per battery. The second phase holds this voltage
> while the current decays to about 2A. The third phase then pulses the
> stack
> 5 seconds on and 5 seconds off with a current of 3.5A, during which the
> voltage is allowed to climb to some level above 14.1V. The third phase
> continues until the dV/dt between pulses drops to below 10mV (per cell?)
> or
> until some time limit for phase 3 is reached (6 hours).
>
> Of course, I've very nervous about how this charger will exceed the
> maximum
> voltage in the Deka gel charging specifications. This is my first
> conversion
> and I don't want to be another person who murders their first battery
> pack.
> They claimed that for traction batteries, this is okay to do and will not
> shorten the life of the batteries (but couldn't explain why). I'm
> speculating that the goal was to trade off a little bit of over-voltaging
> to
> help keep the batteries in the stack better balanced, since undercharging
> can also be a problem in the long run. I did a little research and found
> some stuff about how a small amount of gassing will recombine and not be a
> problem, and someone else claiming a trickle current of 1/100th the power
> rating is okay (which would be 1 A for this battery, which we are pretty
> close to here given the 50% duty cycling of the 3.5A).
>
> http://vrlabattery.onesite.com/blog/2007/12/20/a_comparision_of_agm_and_gel_
> sealed_lead_acid_batt
>
> http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/
> 33539-12v-gel-lead-acid-charger-tweaking-help-needed.html
>
> So their approach may be more or less okay if you don't mind trading off a
> little cycle life for balancing the battery stack. If this is true, I wish
> I
> could quantify it. I would appreciate any advice anyone can give me on
> whether I will be okay with this type of charging profile on a sealed gel
> battery for an EV. Unless there is some solid experience or data on this
> being okay, I'm feeling like I need to switch to a charger that will be a
> little more judicious about limiting the voltage. I asked Elcon if they
> could change to profile to give me what I wanted, but they did not want to
> be responsible for a charging profile other than what they are offering.
>
> Thanks!
> Dave
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[EVDL Administrator]

On 26 Mar 2008 at 18:20, Al Lococo wrote:

> I know the Deka Dominator Gels, are designed to vent, so you may be OK.

It would be interesting to see the source which suggests that. I've been
using Deka Dominators for over 10 years, and I've never heard that they are
designed to vent any more than other valve-regulated batteries are.

I would say the opposite is true. East Penn's charging instructions are
very conservative and should never cause the batteries to vent. If yours
are venting, I would be concerned that you are damaging them, and can expect
relatively short life.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
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email address from the webpage http://www.evdl.org/help/ .
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[Roger Stockton]

EVDL Administrator wrote:

> On 26 Mar 2008 at 18:20, Al Lococo wrote:
>
> > I know the Deka Dominator Gels, are designed to vent, so
> you may be OK.
>
> It would be interesting to see the source which suggests
> that. I've been using Deka Dominators for over 10 years, and
> I've never heard that they are designed to vent any more than
> other valve-regulated batteries are.

I think this is all Al is really stating: that is, that the DEKA gels, like any other VRLA "sealed" battery is designed to vent before the internal pressure can rise high enough for there to be risk of the case rupturing.

What should be made clear is that no VRLA lead acid battery I've ever come across is intended to vent significantly in regular use.

Cheers,

Roger.

[Al Lococo]

David Roden ,

"I've never heard that they are designed to vent any more than other
valve-regulated batteries are."

I agree with that. I was just saying they can and will vent if over
charged. In my opinion no battery should be overcharged, no matter how
gently, (i.e. pulsing) if your concerned about maximum life.

I don't have Dominators. I was referring to their patented vent which I
first heard about from electro automotive in answer to my question about
equalizers. This is what they said:

"When charging a string of batteries in series, some will come to full
charge before the others and gas a little bit while the others come
up to full. On flooded batteries, this means you have to add water
occasionally. On sealed batteries, you can't add water, so you need
to avoid the gassing as much as possible. Dekas have a special
patented vent that releases pressure in a microsecond burst with very
little loss of electrolyte."

I decided to get AGM batteries and use power cheq equalizers to keep them in
step with each other. My only experience is with flooded batteries. I only
have the AGMs a few months. As I said, I'm pulling the plug at the end of
stage two and thinking maybe pulling it at the end of stage one most of the
time.

I am interested in the experiences of people like you who have long term
experience with the NG3 in general and also AGM batteries. From what I read
here, the gels and the AGMs have a lot in common when it comes to charging
requirements.

This my charging experience so far. It is in some respects sketchy. Every
trip is recorded, but some trips lack ending voltage and charge time.

http://www.lococo.org/Electric%20Truck/Milage%20Log.htm

Keep in mind that I have the newer 110 volt NG3 without jumpers for
programming.

Cheers,
Al Lococo



----- Original Message -----
From: "EVDL Administrator" <evpost-***@public.gmane.org>
To: "Electric Vehicle Discussion List" <ev-UWgVIey+***@public.gmane.org>
Sent: Thursday, March 27, 2008 1:04 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> On 26 Mar 2008 at 18:20, Al Lococo wrote:
>
>> I know the Deka Dominator Gels, are designed to vent, so you may be OK.
>
> It would be interesting to see the source which suggests that. I've been
> using Deka Dominators for over 10 years, and I've never heard that they
> are
> designed to vent any more than other valve-regulated batteries are.
>
> I would say the opposite is true. East Penn's charging instructions are
> very conservative and should never cause the batteries to vent. If yours
> are venting, I would be concerned that you are damaging them, and can
> expect
> relatively short life.
>
> David Roden - Akron, Ohio, USA
> EVDL Administrator
>
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> EVDL Information: http://www.evdl.org/help/
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> Note: mail sent to "evpost" or "etpost" addresses will not
> reach me. To send a private message, please obtain my
> email address from the webpage http://www.evdl.org/help/ .
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[Roger Stockton]

Al Lococo wrote:

> I decided to get AGM batteries and use power cheq equalizers
> to keep them in step with each other. My only experience is
> with flooded batteries. I only have the AGMs a few months.
> As I said, I'm pulling the plug at the end of stage two and
> thinking maybe pulling it at the end of stage one most of the time.

Bear in mind that you *must* overcharge lead acid batteries; that is, you must always return at least 5-10% more Ah than were removed in order to bring them to a full state of charge. Lead acid batteries will fail much more rapidly if you routinely undercharge them by 5% than if you overcharge them slightly.

If you feel you have to pull the plug on your charger at the end of the bulk stage most of the time, then sell it and buy a charger that is going to properly charge your batteries. If you are doing shallow cycles, you can probably shut the charger off without letting it perform the entire finish step most of the time, but if you are shutting it down in the first or second step, you will routinely undercharge your batteries.

> This my charging experience so far. It is in some respects
> sketchy. Every trip is recorded, but some trips lack ending
> voltage and charge time.
>
> http://www.lococo.org/Electric%20Truck/Milage%20Log.htm

Great log. Could you explain what the various things you are logging are?

For instance, "return voltage" (I'g guessing this is the resting votlage at the end of your trip, before charging; if so, how long after shutting off the vehicle?); "charge time" is in hours, I assume?.

What exactly are "Volt drop" and "mi/drop", and what information do you feel they provide?

Thanks,

Roger.

[Al Lococo]

Roger,

Thanks for the feedback. As they say the proof is in the pudding. What do
you think of this? I check the voltatge the nex day after the chrge is
completed for several hours. Sometimes, if I don't use the car, it's a day
and ahalf. The voltage before I start ou is about 155 volts (154.9 -
155.5). Isn't that a good way to determine if it is fully charged? I have
stopped the process at the end of stage one, but my usual routine is to let
stage three start the pulsing and stop it early. If left alone to go to
green, the final pulses are 180 volts. This makes me nervious.

I never have stopped stage one before it's done, only at the end of stage
one (early stage two). I have heard of people cycling between 40% and 80%
state of charge. You're saying you should not use this routine. Not that I
have, but I was thinking about it, at least, sometimes.

My chart. The return voltage is measured within minutes of returning,
before pluggin in. Perhaps the real value is higher. I know, while waiting
for my wife in the parking lot, I have watched the needle rise on the volt
meter.

Charge time is a guess, entered the next day based on memory of what time I
plugged in and unplugged. It is in hours.

Drop is the drop in voltage from 155 to the return voltage. Miles per Volt
dropped gives me an idea of far I can go based on voltage if you read the
voltage while stopped. My goal is not to go below 144 volts. Depending on
how aggressively you drive, you can go 2 to 4 miles for each volt above
144. In places these numbers look funny. That is because there are two
trips in the same day with only a partial charge inbetween. Look at the
dates on the entry.

The trip description is useful to me, because, as you can see, many of these
trips are repeated over and over again. I have experimented with shifting,
and decided for me with my gear ratios, second gear works well from 0 to 55
mph. I get gacceptable accelleration in almost all cases. Sometime I will
use first, if I am on an uphill grade. Hard to find in Florida. I will
stop logging soon. I hope this log will be useful as the batteries age.
This log should serve as a benchmark for comparison.

Someone had mentioned a charger that you can program yourself. I have to
look that up. For now I will keep doing what I'm doing, if you agree that
155 volts starting voltage is fully charged. I will abandon the idea of
skipping stage two.

All of my assumptions, good and bad, are in my Design Document, you may have
seen it.

http://www.lococo.org/Electric%20Truck/99%20Ranger.htm


My assumptions about state of charge, gear ratios, etc. are included.

Thanks for your help.

Cheers,
AL Lococo




----- Original Message -----
From: "Roger Stockton" <rstockton-***@public.gmane.org>
To: "'Electric Vehicle Discussion List'" <ev-UWgVIey+***@public.gmane.org>
Sent: Thursday, March 27, 2008 3:39 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> Al Lococo wrote:
>
>> I decided to get AGM batteries and use power cheq equalizers
>> to keep them in step with each other. My only experience is
>> with flooded batteries. I only have the AGMs a few months.
>> As I said, I'm pulling the plug at the end of stage two and
>> thinking maybe pulling it at the end of stage one most of the time.
>
> Bear in mind that you *must* overcharge lead acid batteries; that is, you
> must always return at least 5-10% more Ah than were removed in order to
> bring them to a full state of charge. Lead acid batteries will fail much
> more rapidly if you routinely undercharge them by 5% than if you
> overcharge them slightly.
>
> If you feel you have to pull the plug on your charger at the end of the
> bulk stage most of the time, then sell it and buy a charger that is going
> to properly charge your batteries. If you are doing shallow cycles, you
> can probably shut the charger off without letting it perform the entire
> finish step most of the time, but if you are shutting it down in the first
> or second step, you will routinely undercharge your batteries.
>
>> This my charging experience so far. It is in some respects
>> sketchy. Every trip is recorded, but some trips lack ending
>> voltage and charge time.
>>
>> http://www.lococo.org/Electric%20Truck/Milage%20Log.htm
>
> Great log. Could you explain what the various things you are logging are?
>
> For instance, "return voltage" (I'g guessing this is the resting votlage
> at the end of your trip, before charging; if so, how long after shutting
> off the vehicle?); "charge time" is in hours, I assume?.
>
> What exactly are "Volt drop" and "mi/drop", and what information do you
> feel they provide?
>
> Thanks,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[Roger Stockton]

Al Lococo wrote:

> Thanks for the feedback. As they say the proof is in the
> pudding. What do you think of this? I check the voltatge
> the nex day after the chrge is completed for several hours.
> Sometimes, if I don't use the car, it's a day and ahalf. The
> voltage before I start ou is about 155 volts (154.9 - 155.5).
> Isn't that a good way to determine if it is fully charged?

Yes, it is generally accepted that the OCV many hours after the last charge or discharge is a reasonable indication of SOC.

> I have heard of people
> cycling between 40% and 80% state of charge. You're saying
> you should not use this routine. Not that I have, but I was
> thinking about it, at least, sometimes.

You do not want to do this with lead acid batteries. Lead acid must be fully charged periodically to avoid permanent loss of capacity due to sulfation.

If you are doing short trips, you can certainly charge every other trip or so instead of each trip. For instance, if you do a short trip one day that leaves you at 85-90%SOC, and you know you don't need 100% of your range the next day, you could leave the pack without charging it until after the next trip when the ending SOC might be nearer to 50%. You would not want to leave the pack sitting at 80% or less for very many days, so even if you were at 75-80%SOC, you would want to charge up rather than leave the pack sit for the weekend or longer until the next trip.

When you shut the charger off manually, this is basically what you are doing; that is, operating the pack between two SOCs, neither of which is quite 100% full.

For instance, if you remove 50Ah today and let your charger run at 8.5A for 4hrs in step 1 before halting it, then you have returned 34Ah and the pack is now down only 16Ah. Assuming 200Ah available, this is about 92%SOC. You might operate the vehicle like this during the week, and then let the charger run to completion one night over the weekend to fully top up the batteries. This might be a reasonable regimen if you typically do shallow cycles and/or if you believe that your charger's finish phase is a little too agressive.

> My chart. The return voltage is measured within minutes of
> returning, before pluggin in. Perhaps the real value is
> higher. I know, while waiting for my wife in the parking
> lot, I have watched the needle rise on the volt meter.

Yes, the voltage will typically rise over the next 15-60min (it will continue to rise for longer than this, but I find the voltage is usually pretty close to its final value within perhaps the first hour).

> Drop is the drop in voltage from 155 to the return voltage.
> Miles per Volt dropped gives me an idea of far I can go based
> on voltage if you read the voltage while stopped. My goal is
> not to go below 144 volts. Depending on how aggressively
> you drive, you can go 2 to 4 miles for each volt above 144.

You must have a very light foot! ;^>

The voltage while stopped doesn't really tell you much unless you let the vehicle sit for quite a while (like the 15-60min or longer mentioned above).

More useful is the voltage under load as you drive. 1.75V/cell is considered 100%DOD at whatever load you are drawing; this is 126V for your 144V pack.

> The trip description is useful to me, because, as you can
> see, many of these trips are repeated over and over again.

I hope you didn't think I was being critical of the usefulness of your log; tht is not at all the case. I keep a similar log for my vehicle, though I've been too lazy to put it into the PC or onto the web as you have. It exists as a spiral bound notebook in my glovebox.

It is just that some of the values you were recording are ones I haven't seen before (return voltage, voltage drop, mi/drop) and I wanted to ensure I understood what they meant and why you were logging them.

FWIW, my log includes the date, brief description of the trip, odometer/tripmeter readings, the OCV at the end of the trip, and the Ah and kWh consumed (as reported by the E-Meter).

> I will stop logging soon. I hope this log will be
> useful as the batteries age.
> This log should serve as a benchmark for comparison.

Please don't stop! I'll let the cat out of the bag a bit here; Darin (of ForkenSwift fame) has put together a very slick website on which one can enter this sort of "mileage" log data and have a public record with nice graphs, etc. The present site is oriented towards ICE vehicles, so Darin plans to create a new one oriented toward EVs instead (i.e. allowing energy usage to be entered in kWh instead of gallons of gas, and displaying "mileage" in Wh/mi instead of mpg, etc.). (I hope Darin can include the ability to (optionally?) display EV energy use in mpg equivalent, because I think that would make the site more relavant to non-EVers (or not-yet-EVers ;^) who come across the site online.)

Much of the value of keeping logs such as this is so that you can see trends developing and take corrective action before catastrophic failure occurs. If you log for a while at the start and then stop until you've noticed something odd, you lose much of the benefit of the log in terms of it allowing you to detect when performance starts to deviate slightly from the norm.

> For now I will keep doing what I'm doing, if you agree that
> 155 volts starting voltage is fully charged.

I don't actually agree that 155V is fully charged. This is 12.91-12.92V/battery on average. My AGMs hold 13.1-13.2V each when fully charged. I track Ah in and out, and so am quite confident that mine are fully charged.

> All of my assumptions, good and bad, are in my Design
> Document, you may have seen it.
>
> http://www.lococo.org/Electric%20Truck/99%20Ranger.htm

Very nice.

I would tend to think that your Zivan's algorithm is quite reasonable for your pack, and if anything, might even be on the gentle side. A finish current of 4A-ish is quite reasonable for a 200Ah AGM (and when pulsed, this is only 2A-ish average), and the 15.76V/module max limit is 2.63V/cell, which is also not an unreasonable level. (The algorithm I use on my 55Ah Optimas is nearly this agressive!)

I personally would not have any reservations about letting the charger run to completion, except perhaps when I know I've done a particularly shallow cycle.

If you remain concerned, my suggestion would be to let the charger run to the start of this finish stage each time you charge during the week, and then let the charger run to completion at least once or twice a week.

Cheers,

Roger.

[Al Lococo]

Roger,

Well, tankyou. It is hard to get critisism. It takes time to look over
someelses design and make constructive ideas.
I appreciate it.

I have wanted to get to a plug and drive circumstance. Getting home and
popping the hood and putting the Fluke on is a pain. I have been thinking
about just using the analog volt meter which is a little rough. I'll try to
keep the log going.

I have not been sure that the charger was a real problem, That is after I
turned it down to 168 volts. I did this because the battery manufacturer
is adamant about 172.8 volts (14.4 per battery) maximum charging voltage. I
had some batteries as high as 14.9 when the voltage got started rising to
the mid 170's. The charge algorythim from Zivan was spectd to peak at 171.

The manufacturers discharge graph starts at 13 volts per battery. The 100%
SOC for the pack would be 156 volts then. I am comming within a few tenths
of a volt from this. So I will try letting it run to end of stage three for
my weekly charge after my 26 mile trip for lunch with the guys. Let's see
if that gets me to 156 volts.

Let me ask you this. Do you agree that 40% SOC or 60% DOC is a reasonable
floor. I mean 144 volts, maybe that's 35% DOC. What is OCV? I am curious
about my maximum useful range on the one hand, but on the other hand the car
meets my needs without making unnecessary endurance runs.

You are right I am not an aggressive driver. I use the ammeter to help me
get the best range with the least drain on the battery. I know this is how
many Prius drivers get their best mpg. I have a big investment in batteries
and I want maximum battery life possible. I hope I am on the right track.

Cheers,
Al Lococo
----- Original Message -----
From: "Roger Stockton" <rstockton-***@public.gmane.org>
To: "'Electric Vehicle Discussion List'" <ev-UWgVIey+***@public.gmane.org>
Sent: Thursday, March 27, 2008 6:07 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> Al Lococo wrote:
>
>> Thanks for the feedback. As they say the proof is in the
>> pudding. What do you think of this? I check the voltatge
>> the nex day after the chrge is completed for several hours.
>> Sometimes, if I don't use the car, it's a day and ahalf. The
>> voltage before I start ou is about 155 volts (154.9 - 155.5).
>> Isn't that a good way to determine if it is fully charged?
>
> Yes, it is generally accepted that the OCV many hours after the last
> charge or discharge is a reasonable indication of SOC.
>
>> I have heard of people
>> cycling between 40% and 80% state of charge. You're saying
>> you should not use this routine. Not that I have, but I was
>> thinking about it, at least, sometimes.
>
> You do not want to do this with lead acid batteries. Lead acid must be
> fully charged periodically to avoid permanent loss of capacity due to
> sulfation.
>
> If you are doing short trips, you can certainly charge every other trip or
> so instead of each trip. For instance, if you do a short trip one day
> that leaves you at 85-90%SOC, and you know you don't need 100% of your
> range the next day, you could leave the pack without charging it until
> after the next trip when the ending SOC might be nearer to 50%. You would
> not want to leave the pack sitting at 80% or less for very many days, so
> even if you were at 75-80%SOC, you would want to charge up rather than
> leave the pack sit for the weekend or longer until the next trip.
>
> When you shut the charger off manually, this is basically what you are
> doing; that is, operating the pack between two SOCs, neither of which is
> quite 100% full.
>
> For instance, if you remove 50Ah today and let your charger run at 8.5A
> for 4hrs in step 1 before halting it, then you have returned 34Ah and the
> pack is now down only 16Ah. Assuming 200Ah available, this is about
> 92%SOC. You might operate the vehicle like this during the week, and then
> let the charger run to completion one night over the weekend to fully top
> up the batteries. This might be a reasonable regimen if you typically do
> shallow cycles and/or if you believe that your charger's finish phase is a
> little too agressive.
>
>> My chart. The return voltage is measured within minutes of
>> returning, before pluggin in. Perhaps the real value is
>> higher. I know, while waiting for my wife in the parking
>> lot, I have watched the needle rise on the volt meter.
>
> Yes, the voltage will typically rise over the next 15-60min (it will
> continue to rise for longer than this, but I find the voltage is usually
> pretty close to its final value within perhaps the first hour).
>
>> Drop is the drop in voltage from 155 to the return voltage.
>> Miles per Volt dropped gives me an idea of far I can go based
>> on voltage if you read the voltage while stopped. My goal is
>> not to go below 144 volts. Depending on how aggressively
>> you drive, you can go 2 to 4 miles for each volt above 144.
>
> You must have a very light foot! ;^>
>
> The voltage while stopped doesn't really tell you much unless you let the
> vehicle sit for quite a while (like the 15-60min or longer mentioned
> above).
>
> More useful is the voltage under load as you drive. 1.75V/cell is
> considered 100%DOD at whatever load you are drawing; this is 126V for your
> 144V pack.
>
>> The trip description is useful to me, because, as you can
>> see, many of these trips are repeated over and over again.
>
> I hope you didn't think I was being critical of the usefulness of your
> log; tht is not at all the case. I keep a similar log for my vehicle,
> though I've been too lazy to put it into the PC or onto the web as you
> have. It exists as a spiral bound notebook in my glovebox.
>
> It is just that some of the values you were recording are ones I haven't
> seen before (return voltage, voltage drop, mi/drop) and I wanted to ensure
> I understood what they meant and why you were logging them.
>
> FWIW, my log includes the date, brief description of the trip,
> odometer/tripmeter readings, the OCV at the end of the trip, and the Ah
> and kWh consumed (as reported by the E-Meter).
>
>> I will stop logging soon. I hope this log will be
>> useful as the batteries age.
>> This log should serve as a benchmark for comparison.
>
> Please don't stop! I'll let the cat out of the bag a bit here; Darin (of
> ForkenSwift fame) has put together a very slick website on which one can
> enter this sort of "mileage" log data and have a public record with nice
> graphs, etc. The present site is oriented towards ICE vehicles, so Darin
> plans to create a new one oriented toward EVs instead (i.e. allowing
> energy usage to be entered in kWh instead of gallons of gas, and
> displaying "mileage" in Wh/mi instead of mpg, etc.). (I hope Darin can
> include the ability to (optionally?) display EV energy use in mpg
> equivalent, because I think that would make the site more relavant to
> non-EVers (or not-yet-EVers ;^) who come across the site online.)
>
> Much of the value of keeping logs such as this is so that you can see
> trends developing and take corrective action before catastrophic failure
> occurs. If you log for a while at the start and then stop until you've
> noticed something odd, you lose much of the benefit of the log in terms of
> it allowing you to detect when performance starts to deviate slightly from
> the norm.
>
>> For now I will keep doing what I'm doing, if you agree that
>> 155 volts starting voltage is fully charged.
>
> I don't actually agree that 155V is fully charged. This is
> 12.91-12.92V/battery on average. My AGMs hold 13.1-13.2V each when fully
> charged. I track Ah in and out, and so am quite confident that mine are
> fully charged.
>
>> All of my assumptions, good and bad, are in my Design
>> Document, you may have seen it.
>>
>> http://www.lococo.org/Electric%20Truck/99%20Ranger.htm
>
> Very nice.
>
> I would tend to think that your Zivan's algorithm is quite reasonable for
> your pack, and if anything, might even be on the gentle side. A finish
> current of 4A-ish is quite reasonable for a 200Ah AGM (and when pulsed,
> this is only 2A-ish average), and the 15.76V/module max limit is
> 2.63V/cell, which is also not an unreasonable level. (The algorithm I use
> on my 55Ah Optimas is nearly this agressive!)
>
> I personally would not have any reservations about letting the charger run
> to completion, except perhaps when I know I've done a particularly shallow
> cycle.
>
> If you remain concerned, my suggestion would be to let the charger run to
> the start of this finish stage each time you charge during the week, and
> then let the charger run to completion at least once or twice a week.
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[Roger Stockton]

Al Lococo wrote:

> I have not been sure that the charger was a real problem,
> That is after I turned it down to 168 volts. I did this
> because the battery manufacturer is adamant about 172.8 volts
> (14.4 per battery) maximum charging voltage. I had some
> batteries as high as 14.9 when the voltage got started rising
> to the mid 170's.

The datasheet for your battery states 14.5-14.9V. No temperature is stated, but other specs are stated for 25C/77F, so it is likely the charge voltage is also stated at this temperature. (20C and 25C are common temperatures to spec charge voltages at).

> The charge algorythim from Zivan was
> spectd to peak at 171.

Did you mention having the optional temperature sensor attached?

The info on your site about your charger's configuration doesn't state at what temperature the Zivan's voltage is spec'd. Zivan states that unless otherwise noted, the charger will compensate by 0.005V/cell/degree C when the sensor is used.

This is typical for lead acid. 171V / 72 cells = 2.375V/cell, or 14.25V/battery. This is pretty conservative for cyclic use. If this spec is for 25C, then you should expect the voltage to rise when the batteries are cooler. At 0.005V/cell/deg C, the voltage would be at 2.4V/cell (14.4V/module) at 20C/68F.

14.7V/module is a more typical AGM charge voltage (at 25C), and is in the middle of the spec for your battery. This would increase to 14.85V/battery (178.2V) at 20C/68F.

How warm or cool are your batteries these days?

> The manufacturers discharge graph starts at 13 volts per
> battery.

I wouldn't read too much into the precise details of that graph, if the one you are referring to is the on on the datasheet ;^> It looks to me like the voltage starts pretty darn near the 13.2V line, and the plot isn't nearly detailed enough for you to be able to zoom in and see what the voltage really was just before the load was applied, or for the first few seconds of the discharge.

I've run enough of these tests to say with confidence that an AGM will easily sit over 13V open-circuit when fully charged.

> Let me ask you this. Do you agree that 40% SOC or 60% DOC is
> a reasonable floor.

Its a bit lower than I would take my AGMs if I have a choice. 50% DOD (Depth Of Discharge) is a level that should yield good life from AGMs. If you can cycle them less deeply than this, so much the better, at least until you get into really shallow cycles, such as only 5-10%.

> I mean 144 volts, maybe that's 35% DOC.
> What is OCV? I am curious about my maximum useful range on
> the one hand, but on the other hand the car meets my needs
> without making unnecessary endurance runs.

OCV = Open Circuit Voltage. That is, the pack voltage without any current in or out of it. To be representative of the state of charge (SOC), you need to let the pack rest for at least an hour or so, and ideally several hours.

Failing this, you can take OCV readings that are useful to *you* as long as you take the readings after a consistent amount of rest. These readings may not be accurate if you try to interpret them according to a conventional SOC vs voltage curve, but they can still allow you to determine if the pack is more or less discharged than after some other trip. And, you can always make your own OCV vs SOC curve based on readings you take after only 15min rest or 30min rest, etc.

Cheers,

Roger.

[Al Lococo]

Roger,

Yes I have the temperature sensor installed. The batteries are cool.
Ambient temperature, right now 70 degrees. Charging is not warming them up.

I know what the spec sheet says about charging voltage. This is what the
battery label says.

http://www.lococo.org/Electric%20Truck/Battery%20Label.jpg

Like you said no temperature is stated on the data sheet.

I guess chemistry is chemistry, and the manufacturer is probably more
concerned about warranty than extended battery life, perhaps a
contradiction.

So, are you saying I should ignore the label and go with what we know about
the AGM technology in general (and what the spec sheet says).

My average trip is 17 miles, with a weekly trip of 26 miles and my shortest
trip is 7 miles. occasionally I go 30 or 35 miles. Most trips are 10 to 15
miles. Should not be a lot of shallow cycles.

I agree that 171 or 172 charging voltage is not unreasonable, but it was
much higher than that when I turned it down. The other problem that worried
me, was that some batteries were much higher than others.

So, I guess I should get the pack up to 158.4 volts measured after resting
for several hours, maybe once a week.

And you are suggesting a floor for SOC is maybe 146 volts, not the 144 volts
I was imagining. From what I can see most people are going a lot lower than
that, not that that is desirable. As you can see from my log, I have only
gone below that a few times and not by much.

So, as the log shows,driving as I have been, and charging to only 155.4 is
actually bad for the batteries. As you can see, I am trying to get to
target floor and ceiling voltages for charging and discharging that are
consistent with maximum battery life. Part of my problem is understanding
exactly how critical a tenth of a volt per unit is. I know this is 1.2
volts for the pack, I'm not sure how much capacity this is as a percentage
or in amp hours.

Thanks for your insight.

Cheers,
Al Lococo
----- Original Message -----
From: "Roger Stockton" <rstockton-***@public.gmane.org>
To: "'Electric Vehicle Discussion List'" <ev-UWgVIey+***@public.gmane.org>
Sent: Thursday, March 27, 2008 9:06 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> Al Lococo wrote:
>
>> I have not been sure that the charger was a real problem,
>> That is after I turned it down to 168 volts. I did this
>> because the battery manufacturer is adamant about 172.8 volts
>> (14.4 per battery) maximum charging voltage. I had some
>> batteries as high as 14.9 when the voltage got started rising
>> to the mid 170's.
>
> The datasheet for your battery states 14.5-14.9V. No temperature is
> stated, but other specs are stated for 25C/77F, so it is likely the charge
> voltage is also stated at this temperature. (20C and 25C are common
> temperatures to spec charge voltages at).
>
>> The charge algorythim from Zivan was
>> spectd to peak at 171.
>
> Did you mention having the optional temperature sensor attached?
>
> The info on your site about your charger's configuration doesn't state at
> what temperature the Zivan's voltage is spec'd. Zivan states that unless
> otherwise noted, the charger will compensate by 0.005V/cell/degree C when
> the sensor is used.
>
> This is typical for lead acid. 171V / 72 cells = 2.375V/cell, or
> 14.25V/battery. This is pretty conservative for cyclic use. If this spec
> is for 25C, then you should expect the voltage to rise when the batteries
> are cooler. At 0.005V/cell/deg C, the voltage would be at 2.4V/cell
> (14.4V/module) at 20C/68F.
>
> 14.7V/module is a more typical AGM charge voltage (at 25C), and is in the
> middle of the spec for your battery. This would increase to
> 14.85V/battery (178.2V) at 20C/68F.
>
> How warm or cool are your batteries these days?
>
>> The manufacturers discharge graph starts at 13 volts per
>> battery.
>
> I wouldn't read too much into the precise details of that graph, if the
> one you are referring to is the on on the datasheet ;^> It looks to me
> like the voltage starts pretty darn near the 13.2V line, and the plot
> isn't nearly detailed enough for you to be able to zoom in and see what
> the voltage really was just before the load was applied, or for the first
> few seconds of the discharge.
>
> I've run enough of these tests to say with confidence that an AGM will
> easily sit over 13V open-circuit when fully charged.
>
>> Let me ask you this. Do you agree that 40% SOC or 60% DOC is
>> a reasonable floor.
>
> Its a bit lower than I would take my AGMs if I have a choice. 50% DOD
> (Depth Of Discharge) is a level that should yield good life from AGMs. If
> you can cycle them less deeply than this, so much the better, at least
> until you get into really shallow cycles, such as only 5-10%.
>
>> I mean 144 volts, maybe that's 35% DOC.
>> What is OCV? I am curious about my maximum useful range on
>> the one hand, but on the other hand the car meets my needs
>> without making unnecessary endurance runs.
>
> OCV = Open Circuit Voltage. That is, the pack voltage without any current
> in or out of it. To be representative of the state of charge (SOC), you
> need to let the pack rest for at least an hour or so, and ideally several
> hours.
>
> Failing this, you can take OCV readings that are useful to *you* as long
> as you take the readings after a consistent amount of rest. These
> readings may not be accurate if you try to interpret them according to a
> conventional SOC vs voltage curve, but they can still allow you to
> determine if the pack is more or less discharged than after some other
> trip. And, you can always make your own OCV vs SOC curve based on
> readings you take after only 15min rest or 30min rest, etc.
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[Roger Stockton]

Al Lococo wrote:

> Yes I have the temperature sensor installed. The batteries are cool.
> Ambient temperature, right now 70 degrees. Charging is not
> warming them up.

OK; so we can assume you will (and should) be seeing charge voltages higher than what the datasheet or label state.

> I know what the spec sheet says about charging voltage. This
> is what the battery label says.
>
> http://www.lococo.org/Electric%20Truck/Battery%20Label.jpg
>
> Like you said no temperature is stated on the data sheet.
>
> I guess chemistry is chemistry, and the manufacturer is
> probably more concerned about warranty than extended battery
> life, perhaps a contradiction.
>
> So, are you saying I should ignore the label and go with what
> we know about the AGM technology in general (and what the
> spec sheet says).

Well, I personally would put more faith in the datasheet than in the label.

As it happens, the specific recommendations I have from Universal Power Group themselves is to charge the AGMs to 14.8V max and float at 13.8V. Their recommendation for their GEL models is to charge to 14.4V max and float at 13.6V. These recommendations assume a charge profile that starts provides constant current to the target voltage, then holds this voltage until the current drops to a lowish level, and then switches to float.

If in doubt, I suggest you try to contact an applications engineer at UPG directly and get their take on it. It sounds to me as if the fellow you've been talking to has their GEL and AGM recommendations confused.

> My average trip is 17 miles, with a weekly trip of 26 miles
> and my shortest trip is 7 miles. occasionally I go 30 or 35
> miles. Most trips are 10 to 15 miles. Should not be a lot
> of shallow cycles.

Could be; I can't say. I've got less than 1/4 the energy onboard my EV as you do, and my EV probably uses at least as much energy per mile as yours, so I'd guess that you should still be over 75%SOC after any trip of 10mi or less.

> And you are suggesting a floor for SOC is maybe 146 volts,
> not the 144 volts I was imagining.

No; I'm not suggesting a voltage floor at all. If you want to try to figure out a voltage floor, then what you might try is to use the truck only every other day for a while. Don't plug it in right away when you get home; instead, leave it sit overnight and plug it in in the morning after you record the resting voltage. Plot the resting voltages vs the distance driven that trip. The relationship may not be quite linear, but it will give you an idea of what sort of SOC you are at after having driven various distances. Since you are using OCV after several hours rest, these voltages can be converted to SOC % using a standard table. If the table on your website was derived from the curves on the datasheet for your battery, you might want to doublecheck them against the relationship quot
ed in the Hawker/Odyssey literature. Don't use the relationship quoted for flooded batteries as it will be off a bit for your sealed batteries.

I believe what I mentioned was not to go below 126V under load, and if possible keep the DOD to 50% or less.

> From what I can see most
> people are going a lot lower than that, not that that is
> desirable. As you can see from my log, I have only gone
> below that a few times and not by much.

FWIW, at the end of my commute, my 120V pack would rest at about 122V immediately on parking, and this corresponds to just over 146V for a 144V pack. My pack was pretty much empty at this point!

> So, as the log shows,driving as I have been, and charging to
> only 155.4 is actually bad for the batteries. As you can
> see, I am trying to get to target floor and ceiling voltages
> for charging and discharging that are consistent with maximum
> battery life. Part of my problem is understanding exactly
> how critical a tenth of a volt per unit is. I know this is
> 1.2 volts for the pack, I'm not sure how much capacity this
> is as a percentage or in amp hours.

My sincere advice is that if you want to protect your battery investment, invest in an E-Meter/Link-10! You will have an accurate indication of voltage and current and it will track the Ah and kWh into and out of the pack. If you program it properly for your batteries, it will provide you with a 'fuel guage' display of remaining usable capacity.

Cheers,

Roger.

[Al Lococo]

Roger,

Thanks for all your help. I ran through stage three pulsing as high as 182
at the end.

Now, about ten hours later, the voltage is 155.8 and holding, about a volt
higher than usual 154.8. I'll check it in the morning.

You may have saved my butt. Maybe it is not too late. I am hoping after a
few cycles it may come up a little.

Thanks also too, to many others who, in this thread, and related battery
threads, made helpful comments.

Cheers,
Al Lococo
----- Original Message -----
From: "Roger Stockton" <rstockton-***@public.gmane.org>
To: "'Electric Vehicle Discussion List'" <ev-UWgVIey+***@public.gmane.org>
Sent: Friday, March 28, 2008 1:53 AM
Subject: Re: [EVDL] NG3 Zivan charger and AGM batteries


> Al Lococo wrote:
>
>> Yes I have the temperature sensor installed. The batteries are cool.
>> Ambient temperature, right now 70 degrees. Charging is not
>> warming them up.
>
> OK; so we can assume you will (and should) be seeing charge voltages
> higher than what the datasheet or label state.
>
>> I know what the spec sheet says about charging voltage. This
>> is what the battery label says.
>>
>> http://www.lococo.org/Electric%20Truck/Battery%20Label.jpg
>>
>> Like you said no temperature is stated on the data sheet.
>>
>> I guess chemistry is chemistry, and the manufacturer is
>> probably more concerned about warranty than extended battery
>> life, perhaps a contradiction.
>>
>> So, are you saying I should ignore the label and go with what
>> we know about the AGM technology in general (and what the
>> spec sheet says).
>
> Well, I personally would put more faith in the datasheet than in the
> label.
>
> As it happens, the specific recommendations I have from Universal Power
> Group themselves is to charge the AGMs to 14.8V max and float at 13.8V.
> Their recommendation for their GEL models is to charge to 14.4V max and
> float at 13.6V. These recommendations assume a charge profile that starts
> provides constant current to the target voltage, then holds this voltage
> until the current drops to a lowish level, and then switches to float.
>
> If in doubt, I suggest you try to contact an applications engineer at UPG
> directly and get their take on it. It sounds to me as if the fellow
> you've been talking to has their GEL and AGM recommendations confused.
>
>> My average trip is 17 miles, with a weekly trip of 26 miles
>> and my shortest trip is 7 miles. occasionally I go 30 or 35
>> miles. Most trips are 10 to 15 miles. Should not be a lot
>> of shallow cycles.
>
> Could be; I can't say. I've got less than 1/4 the energy onboard my EV as
> you do, and my EV probably uses at least as much energy per mile as yours,
> so I'd guess that you should still be over 75%SOC after any trip of 10mi
> or less.
>
>> And you are suggesting a floor for SOC is maybe 146 volts,
>> not the 144 volts I was imagining.
>
> No; I'm not suggesting a voltage floor at all. If you want to try to
> figure out a voltage floor, then what you might try is to use the truck
> only every other day for a while. Don't plug it in right away when you
> get home; instead, leave it sit overnight and plug it in in the morning
> after you record the resting voltage. Plot the resting voltages vs the
> distance driven that trip. The relationship may not be quite linear, but
> it will give you an idea of what sort of SOC you are at after having
> driven various distances. Since you are using OCV after several hours
> rest, these voltages can be converted to SOC % using a standard table. If
> the table on your website was derived from the curves on the datasheet for
> your battery, you might want to doublecheck them against the relationship
> quoted in the Hawker/Odyssey literature. Don't use the relationship
> quoted for flooded batteries as it will be off a bit for your sealed
> batteries.
>
> I believe what I mentioned was not to go below 126V under load, and if
> possible keep the DOD to 50% or less.
>
>> From what I can see most
>> people are going a lot lower than that, not that that is
>> desirable. As you can see from my log, I have only gone
>> below that a few times and not by much.
>
> FWIW, at the end of my commute, my 120V pack would rest at about 122V
> immediately on parking, and this corresponds to just over 146V for a 144V
> pack. My pack was pretty much empty at this point!
>
>> So, as the log shows,driving as I have been, and charging to
>> only 155.4 is actually bad for the batteries. As you can
>> see, I am trying to get to target floor and ceiling voltages
>> for charging and discharging that are consistent with maximum
>> battery life. Part of my problem is understanding exactly
>> how critical a tenth of a volt per unit is. I know this is
>> 1.2 volts for the pack, I'm not sure how much capacity this
>> is as a percentage or in amp hours.
>
> My sincere advice is that if you want to protect your battery investment,
> invest in an E-Meter/Link-10! You will have an accurate indication of
> voltage and current and it will track the Ah and kWh into and out of the
> pack. If you program it properly for your batteries, it will provide you
> with a 'fuel guage' display of remaining usable capacity.
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[EVDL Administrator]

On 28 Mar 2008 at 0:52, Al Lococo wrote:

> I guess chemistry is chemistry, and the manufacturer is probably more
> concerned about warranty than extended battery life, perhaps a
> contradiction.

Ah, I see now. These are "Universal" brand batteries.

Unless I'm mistaken, these are generic Chinese AGMs. I believe they're
mainly intended for UPS systems.

If you're lucky, the importer will have someone on staff who has a clue
about how to charge these batteries. If you're not, you'll get a lackey who
takes a guess or just copies the instructions from some other "compatible"
brand.

Batteries are expensive these days, so it's tempting to go low-bid. But
part of what you pay for when you buy a reputable brand (Hawker or East
Penn, for example) is the research and testing they've put into determining
the best way to charge their batteries. You don't usually get much of that
with cheapies.

David Roden - Akron, Ohio, USA
EVDL Administrator

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[EVDL Administrator]

On 27 Mar 2008 at 15:49, Al Lococo wrote:

> I don't have Dominators.

Oops, sorry! I saw the subject ("Deka gel batteries") and assumed that's
what you meant.

> [From East Penn lit]
> "On sealed batteries, you can't add water, so you need to
> avoid the gassing as much as possible. Dekas have a special patented vent
> that releases pressure in a microsecond burst with very little loss of
> electrolyte."

I may be missing something here, but I don't see how any "patented vent" can
help with this. Either you release the gases or you recombine them. If you
release them, water (NOT electrolyte, the distinction is important) is going
to be lost, no matter what the design of the vent.

Maybe they are suggesting that these valves allow more internal pressure,
which I think will result in improved recombination? Just a guess.

My understanding is that with most AGMs, you have to put in a certain amount
of overcharge to reach full on all the cells. If you don't, you will
eventually lose capacity to sulfation. If you overcharge TOO much, you will
eventually lose capacity to grid corrosion as the electrolyte
overconcentrates. Thus, getting the best lifetime AH throughput depends on
a balancing act between the two.

>
> I am interested in the experiences of people like you who have long term
> experience with the NG3 in general and also AGM batteries.

Just to be clear here, I have experience with East Penn gel batteries, but
not with a Zivan personally.

As I mentioned (I think in another thread), a friend of mine had an earlier
Zivan model, K2 I think, and was never able to get a profile for it which he
felt took good care of his flooded golf car batteries. I have heard similar
complaints from some on this list, too, but I don't know what the current
situation is with Zivan's profiles.

Some would no doubt prefer a charger they can tweak themselves. The Zivan
isn't it.

> From what I
> read here, the gels and the AGMs have a lot in common when it comes to
> charging requirements.

That's what East Penn's documentation suggests. The main difference is that
they specify a higher voltage for the AGMs (14.6v vs. 14.1v).

David Roden
EVDL Administrator
http://www.evdl.org/

[Al Lococo]

David,

I have to apologize,we have drifted a little from the original subject of
the thread. I have an NG3 charger but not dominators, and you are in the
reverse circumstance.

Never the less, we have some things in common and I have, with the help of
your comments, Rogers and others, reshaped my thinking. Thanks to all for
that.

I have been too conservative in avoiding over charge. I am trying to get to
the optimal balance as you have pointed out. I hope this has beeen usful to
the original poster, as it has been for me.

Thanks, again.

Cheers,
Al Lococo
----- Original Message -----
From: "EVDL Administrator" <evpost-***@public.gmane.org>
To: "Electric Vehicle Discussion List" <ev-UWgVIey+***@public.gmane.org>
Sent: Thursday, March 27, 2008 8:04 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> On 27 Mar 2008 at 15:49, Al Lococo wrote:
>
>> I don't have Dominators.
>
> Oops, sorry! I saw the subject ("Deka gel batteries") and assumed that's
> what you meant.
>
>> [From East Penn lit]
>> "On sealed batteries, you can't add water, so you need to
>> avoid the gassing as much as possible. Dekas have a special patented
>> vent
>> that releases pressure in a microsecond burst with very little loss of
>> electrolyte."
>
> I may be missing something here, but I don't see how any "patented vent"
> can
> help with this. Either you release the gases or you recombine them. If
> you
> release them, water (NOT electrolyte, the distinction is important) is
> going
> to be lost, no matter what the design of the vent.
>
> Maybe they are suggesting that these valves allow more internal pressure,
> which I think will result in improved recombination? Just a guess.
>
> My understanding is that with most AGMs, you have to put in a certain
> amount
> of overcharge to reach full on all the cells. If you don't, you will
> eventually lose capacity to sulfation. If you overcharge TOO much, you
> will
> eventually lose capacity to grid corrosion as the electrolyte
> overconcentrates. Thus, getting the best lifetime AH throughput depends
> on
> a balancing act between the two.
>
>>
>> I am interested in the experiences of people like you who have long term
>> experience with the NG3 in general and also AGM batteries.
>
> Just to be clear here, I have experience with East Penn gel batteries, but
> not with a Zivan personally.
>
> As I mentioned (I think in another thread), a friend of mine had an
> earlier
> Zivan model, K2 I think, and was never able to get a profile for it which
> he
> felt took good care of his flooded golf car batteries. I have heard
> similar
> complaints from some on this list, too, but I don't know what the current
> situation is with Zivan's profiles.
>
> Some would no doubt prefer a charger they can tweak themselves. The Zivan
> isn't it.
>
>> From what I
>> read here, the gels and the AGMs have a lot in common when it comes to
>> charging requirements.
>
> That's what East Penn's documentation suggests. The main difference is
> that
> they specify a higher voltage for the AGMs (14.6v vs. 14.1v).
>
> David Roden
> EVDL Administrator
> http://www.evdl.org/
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[k***@public.gmane.org]

Well, for what it's worth here is my experience.

I have the same NG3 with the same profile except the T2 current is 2.5
amps.

The car is driven (aggressively) every day and gets three complete
cycles each day - including the pulse phase.
1) drive to work, charge. 2) drive to lunch, run errands, charge. 3)
drive home, charge.
Each charge runs all three phases completely. The "high" batteries
reach up to 16 volts during the pulse on, near the end of the pulse
phase (204 volts total). Note: as the dt/dv (rate of voltage change
between pulse on and pulse off) decreases, the on pulses get shorter.
Eventually, the pulses are just a few milliseconds long.

Occasionally, the car will make a very short trip or just get moved
around in the driveway. It always gets plugged back in and the Zivan
skips to the pulse phase. So, sometimes it gets extra pulse phase
charging.

No battery has ever gassed. This same routine takes place all year,
cold and hot. It gets hot, here in Austin Texas. Often the Zivan would
not charge after the drive home during July to September, because the
ambient temperature is over 120 degrees. By ambient, I mean the car
body, batteries etc. The pavement temperature is over 140 degrees. I
would have to park in shade open everything up and put fans on it to
get it under 120 degrees before the Zivan would run. At the end of each
charging session after the Zivan turns off, the AH reads +2. Each
morning, after the pack has sat for about 10 hours off charge, the 156
volt pack is sitting at 168 volts.

With all this, I got well over 500 cycles out of the first set of
Optimas. I replaced them with a set of Odyssey PC1200's. The original
set of Optimas are still good and are being used as a stationary test
pack for Hot Juice Electric.

Ken



-----Original Message-----
From: Al Lococo <al-hfXhAMO4Guodnm+***@public.gmane.org>
To: Electric Vehicle Discussion List <ev-UWgVIey+***@public.gmane.org>
Sent: Thu, 27 Mar 2008 2:49 pm
Subject: Re: [EVDL] Zivan charger and Deka gel batteries



David Roden ,

"I've never heard that they are designed to vent any more than other
valve-regulated batteries are."

I agree with that. I was just saying they can and will vent if over
charged. In my opinion no battery should be overcharged, no matter how
gently, (i.e. pulsing) if your concerned about maximum life.

I don't have Dominators. I was referring to their patented vent which I
first heard about from electro automotive in answer to my question
about
equalizers. This is what they said:

"When charging a string of batteries in series, some will come to full
charge before the others and gas a little bit while the others come
up to full. On flooded batteries, this means you have to add water
occasionally. On sealed batteries, you can't add water, so you need
to avoid the gassing as much as possible. Dekas have a special
patented vent that releases pressure in a microsecond burst with very
little loss of electrolyte."

I decided to get AGM batteries and use power cheq equalizers to keep
them in
step with each other. My only experience is with flooded batteries. I
only
have the AGMs a few months. As I said, I'm pulling the plug at the end
of
stage two and thinking maybe pulling it at the end of stage one most of
the
time.

I am interested in the experiences of people like you who have long
term
experience with the NG3 in general and also AGM batteries. From what I
read
here, the gels and the AGMs have a lot in common when it comes to
charging
requirements.

This my charging experience so far. It is in some respects sketchy.
Every
trip is recorded, but some trips lack ending voltage and charge time.

http://www.lococo.org/Electric%20Truck/Milage%20Log.htm

Keep in mind that I have the newer 110 volt NG3 without jumpers for
programming.

Cheers,
Al Lococo



----- Original Message -----
From: "EVDL Administrator" <evpost-***@public.gmane.org>
To: "Electric Vehicle Discussion List" <ev-UWgVIey+***@public.gmane.org>
Sent: Thursday, March 27, 2008 1:04 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> On 26 Mar 2008 at 18:20, Al Lococo wrote:
>
>> I know the Deka Dominator Gels, are designed to vent, so you may be
OK.
>
> It would be interesting to see the source which suggests that. I've
been
> using Deka Dominators for over 10 years, and I've never heard that
they
> are
> designed to vent any more than other valve-regulated batteries are.
>
> I would say the opposite is true. East Penn's charging instructions
are
> very conservative and should never cause the batteries to vent. If
yours
> are venting, I would be concerned that you are damaging them, and can
> expect
> relatively short life.
>
> David Roden - Akron, Ohio, USA
> EVDL Administrator
>
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> EVDL Information: http://www.evdl.org/help/
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> Note: mail sent to "evpost" or "etpost" addresses will not
> reach me. To send a private message, please obtain my
> email address from the webpage http://www.evdl.org/help/ .
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

[Jeff Mccabe]

Thanks Ken, this is useful to compare my 156volt
pc15oo pack to.
Your right, the overnight ocv is right around 168+
Jeff McCabe
--- kenscircus-***@public.gmane.org wrote:

> Well, for what it's worth here is my experience.
>
> I have the same NG3 with the same profile except the
> T2 current is 2.5
> amps.
>
> The car is driven (aggressively) every day and gets
> three complete
> cycles each day - including the pulse phase.
> 1) drive to work, charge. 2) drive to lunch, run
> errands, charge. 3)
> drive home, charge.
> Each charge runs all three phases completely. The
> "high" batteries
> reach up to 16 volts during the pulse on, near the
> end of the pulse
> phase (204 volts total). Note: as the dt/dv (rate of
> voltage change
> between pulse on and pulse off) decreases, the on
> pulses get shorter.
> Eventually, the pulses are just a few milliseconds
> long.
>
> Occasionally, the car will make a very short trip or
> just get moved
> around in the driveway. It always gets plugged back
> in and the Zivan
> skips to the pulse phase. So, sometimes it gets
> extra pulse phase
> charging.
>
> No battery has ever gassed. This same routine takes
> place all year,
> cold and hot. It gets hot, here in Austin Texas.
> Often the Zivan would
> not charge after the drive home during July to
> September, because the
> ambient temperature is over 120 degrees. By ambient,
> I mean the car
> body, batteries etc. The pavement temperature is
> over 140 degrees. I
> would have to park in shade open everything up and
> put fans on it to
> get it under 120 degrees before the Zivan would run.
> At the end of each
> charging session after the Zivan turns off, the AH
> reads +2. Each
> morning, after the pack has sat for about 10 hours
> off charge, the 156
> volt pack is sitting at 168 volts.
>
> With all this, I got well over 500 cycles out of the
> first set of
> Optimas. I replaced them with a set of Odyssey
> PC1200's. The original
> set of Optimas are still good and are being used as
> a stationary test
> pack for Hot Juice Electric.
>
> Ken
>
>
>
> -----Original Message-----
> From: Al Lococo <al-hfXhAMO4Guodnm+***@public.gmane.org>
> To: Electric Vehicle Discussion List
> <ev-UWgVIey+***@public.gmane.org>
> Sent: Thu, 27 Mar 2008 2:49 pm
> Subject: Re: [EVDL] Zivan charger and Deka gel
> batteries
>
>
>
> David Roden ,
>
> "I've never heard that they are designed to vent any
> more than other
> valve-regulated batteries are."
>
> I agree with that. I was just saying they can and
> will vent if over
> charged. In my opinion no battery should be
> overcharged, no matter how
> gently, (i.e. pulsing) if your concerned about
> maximum life.
>
> I don't have Dominators. I was referring to their
> patented vent which I
> first heard about from electro automotive in answer
> to my question
> about
> equalizers. This is what they said:
>
> "When charging a string of batteries in series, some
> will come to full
> charge before the others and gas a little bit while
> the others come
> up to full. On flooded batteries, this means you
> have to add water
> occasionally. On sealed batteries, you can't add
> water, so you need
> to avoid the gassing as much as possible. Dekas have
> a special
> patented vent that releases pressure in a
> microsecond burst with very
> little loss of electrolyte."
>
> I decided to get AGM batteries and use power cheq
> equalizers to keep
> them in
> step with each other. My only experience is with
> flooded batteries. I
> only
> have the AGMs a few months. As I said, I'm pulling
> the plug at the end
> of
> stage two and thinking maybe pulling it at the end
> of stage one most of
> the
> time.
>
> I am interested in the experiences of people like
> you who have long
> term
> experience with the NG3 in general and also AGM
> batteries. From what I
> read
> here, the gels and the AGMs have a lot in common
> when it comes to
> charging
> requirements.
>
> This my charging experience so far. It is in some
> respects sketchy.
> Every
> trip is recorded, but some trips lack ending voltage
> and charge time.
>
>
http://www.lococo.org/Electric%20Truck/Milage%20Log.htm
>
> Keep in mind that I have the newer 110 volt NG3
> without jumpers for
> programming.
>
> Cheers,
> Al Lococo
>
>
>
> ----- Original Message -----
> From: "EVDL Administrator" <evpost-***@public.gmane.org>
> To: "Electric Vehicle Discussion List"
> <ev-UWgVIey+***@public.gmane.org>
> Sent: Thursday, March 27, 2008 1:04 PM
> Subject: Re: [EVDL] Zivan charger and Deka gel
> batteries
>
>
> > On 26 Mar 2008 at 18:20, Al Lococo wrote:
> >
> >> I know the Deka Dominator Gels, are designed to
> vent, so you may be
> OK.
> >
> > It would be interesting to see the source which
> suggests that. I've
> been
> > using Deka Dominators for over 10 years, and I've
> never heard that
> they
> > are
> > designed to vent any more than other
> valve-regulated batteries are.
> >
> > I would say the opposite is true. East Penn's
> charging instructions
> are
> > very conservative and should never cause the
> batteries to vent. If
> yours
> > are venting, I would be concerned that you are
> damaging them, and can
> > expect
> > relatively short life.
> >
> > David Roden - Akron, Ohio, USA
> > EVDL Administrator
> >
> > = = = = = = = = = = = = = = = = = = = = = = = = =
> = = = =
> > EVDL Information: http://www.evdl.org/help/
> > = = = = = = = = = = = = = = = = = = = = = = = = =
> = = = =
> > Note: mail sent to "evpost" or "etpost" addresses
> will not
> > reach me. To send a private message, please obtain
> my
> > email address from the webpage
> http://www.evdl.org/help/ .
> > = = = = = = = = = = = = = = = = = = = = = = = = =
> = = = =
>
=== message truncated ===

[Lee Hart]

From: Al Lococo
> I have an NG3 120Volt on board with 12 120 pound UB4D AGM batteries.
> My charger was exceeding the battery manufacturers recommendation
> (14.1-14.4v). I don't know how high it would go, I pulled the plug at
> 175 volts in stage one (it was supposed to stop at 171 volts).

175v is 14.58v per 12v battery; not excessive *if* you limit the amphours (time x amps).

> I decided my battery pack is worth more than the charger.

A good decision!

> I then found stage three was peaking its pulses at 180 volts.

That's 15v per 12v battery; about as high as you want an AGM to get. At this voltage, the battery is essentially fully charged. Virtually no current is going into charging; it all goes into heating, gassing, and equalization. So, it is vital to limit the time and current in this stage.

>I use eleven battery Cheq equalizers.

Batticheq? PowerCheq?

> In the end, you are the one who I believe is responsible for your
> battery life.

Very true! The battery and charger manufacturers often don't talk to each other, and neither really knows your situation as well as you do. Each has reasons to give less-than-ideal advice.

> I wish I could program the charger myself. I would like it to stop
> after stage two is finished. I am thinking about a clock where I can
> set the time. I find, I need about three hours of charge for every 10
> miles.

Ultimate, you need a way to *know* what state of charge the batteries are at. Charge until they are full, plus a few percent more to make up for losses, and then stop.

The trouble is, the charger doesn't really know the state of charge. It guesses using voltage; but voltage is a rather weak indicator. If you have a better way to know state of charge, use that instead to control the charger. It could be a hydrometer (for flooded batteries), or an E-meter or other amphour counter, or by measuring the resting voltage after sitting overnight, etc.

--
Those who say it cannot be done should not interrupt the one who is
doing it. -- Chinese proverb
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

[Al Lococo]

Lee,

Thanks for the feedback. I am using Power cheq equalizers.

I see Jeff McCabe mentioned using a clock to pull the plug at the end of
Stage 2 before equalization starts. I may do this too.

>From what you say the charger won't hurt things much the way it is
programmed, but still it is way over the battery manufacturers conservative
linits at points. Especially before I turned down the voltage. I don't
know where it was going.

I am going to keep doing what I have been, pulling the plug early in stage
3, and from what I'm reading, and I have also done this, maybe I should stop
at the end of stage 1. When I have done this, it hasn't had a noticeable
affect on my range. I never get to less than 145 volts. My average trip
ends at about 149 volts, so I don't need to drive it to 100% charge.

Thanks again.

Cheers,
Al Lococo




----- Original Message -----
From: "Lee Hart" <leeahart-***@public.gmane.org>
To: "Electric Vehicle Discussion List" <ev-UWgVIey+***@public.gmane.org>
Sent: Wednesday, March 26, 2008 8:22 PM
Subject: Re: [EVDL] Zivan charger and Deka gel batteries


> From: Al Lococo
>> I have an NG3 120Volt on board with 12 120 pound UB4D AGM batteries.
>> My charger was exceeding the battery manufacturers recommendation
>> (14.1-14.4v). I don't know how high it would go, I pulled the plug at
>> 175 volts in stage one (it was supposed to stop at 171 volts).
>
> 175v is 14.58v per 12v battery; not excessive *if* you limit the amphours
> (time x amps).
>
>> I decided my battery pack is worth more than the charger.
>
> A good decision!
>
>> I then found stage three was peaking its pulses at 180 volts.
>
> That's 15v per 12v battery; about as high as you want an AGM to get. At
> this voltage, the battery is essentially fully charged. Virtually no
> current is going into charging; it all goes into heating, gassing, and
> equalization. So, it is vital to limit the time and current in this stage.
>
>>I use eleven battery Cheq equalizers.
>
> Batticheq? PowerCheq?
>
>> In the end, you are the one who I believe is responsible for your
>> battery life.
>
> Very true! The battery and charger manufacturers often don't talk to each
> other, and neither really knows your situation as well as you do. Each has
> reasons to give less-than-ideal advice.
>
>> I wish I could program the charger myself. I would like it to stop
>> after stage two is finished. I am thinking about a clock where I can
>> set the time. I find, I need about three hours of charge for every 10
>> miles.
>
> Ultimate, you need a way to *know* what state of charge the batteries are
> at. Charge until they are full, plus a few percent more to make up for
> losses, and then stop.
>
> The trouble is, the charger doesn't really know the state of charge. It
> guesses using voltage; but voltage is a rather weak indicator. If you have
> a better way to know state of charge, use that instead to control the
> charger. It could be a hydrometer (for flooded batteries), or an E-meter
> or other amphour counter, or by measuring the resting voltage after
> sitting overnight, etc.
>
> --
> Those who say it cannot be done should not interrupt the one who is
> doing it. -- Chinese proverb
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>

[EVDL Administrator]

On 28 Mar 2008 at 0:52, Al Lococo wrote:

> I guess chemistry is chemistry, and the manufacturer is probably more
> concerned about warranty than extended battery life, perhaps a
> contradiction.

Ah, I see now. These are "Universal" brand batteries.

Unless I'm mistaken, these are generic Chinese AGMs. I believe they're mainly
intended for UPS systems.

If you're lucky, the importer will have someone on staff who has a clue about
how to charge these batteries. If you're not, you'll get a lackey who takes a
guess or just copies the instructions from some other "compatible" brand.

Batteries are expensive these days, so it's tempting to go low-bid. But part
of what you pay for when you buy a reputable brand (Hawker or East Penn, for
example) is the research and testing they've put into determining the best way
to charge their batteries. You don't usually get much of that with cheapies.