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Discussion Starter · #1 ·
Well, since I had a battery venting for no apparent reason (not over
voltage, and not reversed) I pulled half the pack out of my Sparrow.
(Royal Pain in the Posterior)
What I'm doing now is putting each one on my Bench Power Supply, set to
14.50v. I let them charge until they are drawing only 1.4A.

Of the 4 I've done so far, 2 started a little hiss venting when they
were down to about 1.5A charging, 1 didn't vent at all, and 1 started
venting at 3A! These are all with the voltage being held at a steady
14.50v.

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Discussion Starter · #2 ·
John G. Lussmyer wrote:

> Of the 4 I've done so far, 2 started a little hiss venting when they
> were down to about 1.5A charging, 1 didn't vent at all, and 1 started
> venting at 3A! These are all with the voltage being held at a steady
> 14.50v.

A few years back, Paul Compton posted about having "blueprinted" the
vents on his Optimas. As I recall, he found that they were venting too
easily due to some platsic flash on the vent pipes. If you pry out the
flame arrestor disc over the vent, you can then remove the rubber nipple
and inspect the vent tube to see if any plastic flash needs to be
removed. Reassemble after cleaning any flash with a sharp knife.

I have found that Optimas may vent a bit if they have been sitting for
some time. My hypothesis is that differing self-discharge rates between
the cells leads to relatively significant imbalance between the cells if
the battery if left sitting long enough. I've found that Optimas can
easily vent at <14V when in this condition.

My experience has been that placing an ordinary 100W 120V lightbulb in
series with each battery and connecting them to a ~15V power supply
allows them to gently come up to full charge with a minimum of venting.
The current to each battery is individually limited to about 100mA by
the bulb in series with each. Leave the batteries charging like this
for a few days to a week. After this you should be able to put the
batteries in service without any venting.

Good luck,

Roger.

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Discussion Starter · #3 ·
Okay, so I finished charging every battery at 14.50volts, down to 1.4A.
Some took longer, some did some venting.
I then took the Sparrow out for a spin around the block. 6.6 miles over
rolling hills at 40-50mph. This used 1.27 KWH.
At about the 4 mile mark, I noticed that the voltage was dropping down
to 140v with only a 120A draw. (up a slight hill.)

As soon as I got home, I checked the voltages on all 13 Optimas.
12.43, 12.45, 12.44, 12.40, 12.45, 10.68, 12.42, 12.44, 12.49, 12.43,
12.43, 11.43, 12.37

Note that batteries #6 and #12 show problems. #12 was venting a
little. The reg on #6 had it's undervoltage light lit. #12 doesn't
currently have a reg attached.

Looks like I have 2 bad batteries. sigh.

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Discussion Starter · #4 ·
Hey John,

Well that is bad news, but, it makes me feel a bit better. I say that
because I had the same experience. After about 2000 miles on our new
NmG - with a new pack we had three batteries fail. I never heard them
venting. I have bad hearing and could have missed it, but I don't think
so because Heidi has excellent hearing and she is very observant in
that way.

Anyway, I contacted Optima and spoke to Bridget regarding warranty
replacement. She informed me that using Optima batteries in an electric
vehicle voids any warranty. That is regardless of charger type, battery
management or whatever - No warranty if used in an EV.

Just curious, have you checked with them regarding warranty?

Ken





-----Original Message-----
From: John G. Lussmyer <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>;
[email protected]
Sent: Tue, 4 Sep 2007 8:48 pm

Subject: [EVDL] New Optima pack

Okay, so I finished charging every battery at 14.50volts, down to 1.4A.
Some took longer, some did some venting.
I then took the Sparrow out for a spin around the block. 6.6 miles over
rolling hills at 40-50mph. This used 1.27 KWH.
At about the 4 mile mark, I noticed that the voltage was dropping down
to 140v with only a 120A draw. (up a slight hill.)

As soon as I got home, I checked the voltages on all 13 Optimas.
12.43, 12.45, 12.44, 12.40, 12.45, 10.68, 12.42, 12.44, 12.49, 12.43,
12.43, 11.43, 12.37

Note that batteries #6 and #12 show problems. #12 was venting a
little. The reg on #6 had it's undervoltage light lit. #12 doesn't
currently have a reg attached.

Looks like I have 2 bad batteries. sigh.

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Discussion Starter · #5 ·
Jeff Shanab wrote:
> Did you say you stopped chargeing at 1.4Amps? Is this a regulated
> 14.5Volt supply?
> You may be obscureing your SOC.
>
Using a Lab Bench power supply, charge at 14.50V until current drops to
1.4A. This was to just get them all to close to the same SOC. This was
a BRAND NEW pack. NEVER used.
> I think you are chronically underchargeing and then sucking them to low,
> which lessens their capacity which makes the situation
>
Hard to be chronic since this was the first real charge cycle.
> worse....Batteries need to be woken up slowly, hitting them too hard to
> soon will cause venting and imbalance if they have sat for any time.
>
I'm trying short runs to break them in. But those 2 batteries seem to
be bad.

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Discussion Starter · #6 ·
John G. Lussmyer writes:
>
> Jeff Shanab wrote:
> > Did you say you stopped chargeing at 1.4Amps? Is this a regulated
> > 14.5Volt supply?
> > You may be obscureing your SOC.
>
> Using a Lab Bench power supply, charge at 14.50V until current drops to
> 1.4A. This was to just get them all to close to the same SOC. This was
> a BRAND NEW pack. NEVER used.

John,

Did you follow the taper with a 2 amp constant current charge for an hour?
You need to completely disable the regulators during this phase, since the
battery voltageis will get quite high, maybe even up to 17 volts.

On the two batteries that are 'bad', try discharging them at 25 amps down
to 10.5v, then give them a proper charge (any current until 14.7v, hold
14.7v until the current drops below 1 amp, then do 2 amps for an hour with
no voltage limit). You might find that these batteries are just
undercharged.

Ralph

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Discussion Starter · #7 ·
Ralph said
"Did you follow the taper with a 2 amp constant current charge for an hour?
You need to completely disable the regulators during this phase, since the
battery voltageis will get quite high, maybe even up to 17 volts."

Are optima's significantly differnet than orbitals?

I don't think this is a good idea for optima's. Never go over 14V and never go over an amp once over 14.5V.
Maybe this is a floodie technique? Optima's have a platinum pellet in the battery top that acts as a re-combiner to take the hydrogen that has gassed and recombine it back with the avail o2 into water. If you exceed this little pellet's capacity the pressure builds and you pop a vent. From what I am told thye can handle about 1 amp worth of gassing.

I got lucky with the orbitals(exide brand) that I had gotten. They knew up front they were going in an EV and honored the warrentee.

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Discussion Starter · #8 ·
[EVDL] New Optima Pack

I just re-read the optima and the orbital chargeing spec. Maybe I am
undercharging my pack.

How do I do an IUI charge with the typical PFC charger and regulator set
up? Is this the best way? Every Charge ?

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Discussion Starter · #9 ·
> Never go over 14V and never go over an amp once over 14.5V.

Just a little friendly ribbing here. But, how can the second part even be possible? ;-)

Did you mean never go over 15v?


reminds me of a multiple guess test I once took, the answers went something like....

a. cold
b. snow
c. rain
d. none of the above
e. all of the above


--
Stay Charged!
Hump
I-5, Blossvale NY

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Discussion Starter · #10 ·
Re: [EVDL] New Optima Pack

Jeff Shanab writes:
>
> I just re-read the optima and the orbital chargeing spec. Maybe I am
> undercharging my pack.
>
> How do I do an IUI charge with the typical PFC charger and regulator set
> up? Is this the best way? Every Charge ?

You can't run the published Optima charge profile without disconnecting
the regulators for the final phase. The voltage has to be uncontrolled,
and it will exceed the limit settings of the regulator, even when they're
in 'equalize' mode.

There are many opinions about how often the final phase needs to be done
(and even *if* it should be done). The spec assumes that the battery has
just been discharged down to 10.5v. If you aren't discharging this deeply,
a couple of obvious choices for the final phase are to either run it for
some percentage of an hour every charge cycle, or to count amp hours drawn
out and only run the final phase every <rated AH> (55AH for the Optimas).
I'm leaning towards the second choice, which for my commute works out to
running the final phase every other charge cycle.

Ralph

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Discussion Starter · #11 ·
Ralph Merwin wrote:
> On the two batteries that are 'bad', try discharging them at 25 amps down
> to 10.5v, then give them a proper charge (any current until 14.7v, hold
> 14.7v until the current drops below 1 amp, then do 2 amps for an hour with
> no voltage limit). You might find that these batteries are just
> undercharged.
Fun part is that I've discovered I haven't yet replaced all my "tools"
that were burned last year.
I don't have anything to do a controlled discharge with.
So yesterday, I went out to the bird, and use a single 20A charger on
various batteries. I checked several "good" ones with the charger, and
it said they were all at 100% charge.
#12 (weak) was at 90%, and the charger brought it up in about 10 minutes.
#6 (really weak) was at 12%. The charger worked on it for over an hour,
and brought it up to 86% - and held at that level.
So, I did another short drive, and checked the battery voltages
immediately afterward.
#12 was again at 11.23, (all the good batteries were about 12.23)
#6 dropped below 10V during the run again, and was at about 10.23v
afterward. It had also developed a hot spot at one end. You could feel
the case was hot down near one post. The rest of the battery top was at
a normal temp.
#6 is also "filled" first on charge with the PFC 40 charger. It's reg
started triggering pretty quick.
I've left everything sit overnight, now I'm going to go out and see what
the resting voltages are.

I'm pretty sure #6 has a bad cell, and #12 doesn't look real good either.

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Discussion Starter · #12 ·
John G. Lussmyer wrote:
> I've left everything sit overnight, now I'm going to go out and see what
> the resting voltages are.
>
> I'm pretty sure #6 has a bad cell, and #12 doesn't look real good either.
>
Okay, checked the voltages. All the "good" batteries are reading 12.80v
to 12.90v.
#12 was at 12.67, #6 was at 11.61.

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Discussion Starter · #13 ·
John G. Lussmyer writes:
>
> John G. Lussmyer wrote:
> > I've left everything sit overnight, now I'm going to go out and see what
> > the resting voltages are.
> >
> > I'm pretty sure #6 has a bad cell, and #12 doesn't look real good either.
> >
> Okay, checked the voltages. All the "good" batteries are reading 12.80v
> to 12.90v.
> #12 was at 12.67, #6 was at 11.61.

John,

If these are resting voltages after sitting overnight after a full charge,
your batteries aren't fully charged. They should be closer to 13.0v or
13.1v. I have some that hold about 13.1v for several days...

Have you tried running the published spec on either of the two "bad" ones?

Ralph

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Discussion Starter · #14 ·
Ralph Merwin wrote:
> If these are resting voltages after sitting overnight after a full charge,
> your batteries aren't fully charged. They should be closer to 13.0v or
> 13.1v. I have some that hold about 13.1v for several days...
>
> Have you tried running the published spec on either of the two "bad" ones?
>
I'm running a 2A finish charge now. I've set the regs for equalize
mode, and if they start coming on I'll disconnect them.

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Discussion Starter · #15 ·
Ralph Merwin wrote:

> If these are resting voltages after sitting overnight
> after a full charge, your batteries aren't fully charged.

John, based on your observation of a hot spot on one of the cells of
battery #6, I would strongly suggest that you remove it from the vehicle
immediately. Even if you have good insurance, it can't be that much fun
searching for another Sparrow if this one goes up in flames. The hot
spot suggests an internal short; it may not be a dead short yet, but if
you're going to continue to experiment on this battery to see if you can
make it usable, better to have it somewhere on its own where it won't be
a crisis if it melts down.

There may still be hope for #12, but I'd try to get warranty on #6 (I
know you said they told you no warranty on batteries used in EVs, but if
you walk in with a single blue top and can point to a definite hotspot
on it as the defect, a sympathetic counterperson may still exchange it
for you). I'm pretty sure that Al Godfrey was able to get a warranty
replacement when one of the 26 blue tops in his 928 was identified as
substandard within the warranty period.

> They should be closer to 13.0v or 13.1v. I have some
> that hold about 13.1v for several days...

Some? FWIW, even your old blems in my car will hold 13.0-13.2V for days.

> Have you tried running the published spec on either of the
> two "bad" ones?

At the very least, do as Ralph suggests and run the Optima recommended
profile. Or, if you are willing to take it more slowly, float the
battery as I suggested in an earlier message; the slow and sure approach
does work.

Cheers,

Roger.


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Discussion Starter · #16 ·
Roger Stockton writes:
>
> John, based on your observation of a hot spot on one of the cells of
> battery #6, I would strongly suggest that you remove it from the vehicle
> immediately. Even if you have good insurance, it can't be that much fun

I missed the comment about the hot spot. Ditto Roger's comment about
removing that battery from the vehicle right now... It probably gets
hot while driving too.


> > They should be closer to 13.0v or 13.1v. I have some
> > that hold about 13.1v for several days...
>
> Some? FWIW, even your old blems in my car will hold 13.0-13.2V for days.

I should've said 'most'. I have one that won't. It also gets warmer
than the others while charing.

Ralph

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Discussion Starter · #17 ·
Ralph Merwin wrote:
> I missed the comment about the hot spot. Ditto Roger's comment about
> removing that battery from the vehicle right now... It probably gets
> hot while driving too.
>
Actually, it only got hot during discharge. Cooled off during charge.
Still, it's definitely a bad battery.
> I should've said 'most'. I have one that won't. It also gets warmer
> than the others while charing.
>
Most things get hot while "charing"... :)

I let the batteries sit for a couple hours after an hour+ at a 2A charge
rate.
Now they are all in the 12.95 to 13.05 range - except #12 which is at
12.77, and #6 at 11.80.

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Discussion Starter · #18 ·
Re: [EVDL] New Optima Pack

Jeff Shanab wrote:

> I don't think this is a good idea for optima's. Never go over
> 14V and never go over an amp once over 14.5V.
> Maybe this is a floodie technique? Optima's have a platinum
> pellet in the battery top that acts as a re-combiner to take
> the hydrogen that has gassed and recombine it back with the
> avail o2 into water. If you exceed this little pellet's
> capacity the pressure builds and you pop a vent. From what I
> am told thye can handle about 1 amp worth of gassing.

A healthy Optima (D34) is supposed to be able to take 4A "indefinitely",
though you don't really want to do this as it will vent some. What you
can do to an individual battery is also different from what you can do
to a string of batteries.

If the cells in an Optima are imbalanced it can vent with less than 1A
and less than 14V on it; bypass regs are no guarantee that you won't
vent your batteries on charge, though they are certainly better than
nothing.

> I just re-read the optima and the orbital chargeing spec. Maybe I am
> undercharging my pack.

Anytime you have under-performing batteries after a very low number of
cycles, suspect undercharging. Over-charging will also kill your
batteries, but unless it is extreme it will take longer before you
notice.

> How do I do an IUI charge with the typical PFC charger and
> regulator set up? Is this the best way? Every Charge ?

As Ralph notes, you need to disable the regs to do the final I step,
otherwise they kick in to clamp the voltage and prevent the battery from
getting the appropriate overcharge.

You also need to readjust your charger's voltage and current limits.
You need to open up the voltage limit so that the battery voltage can go
where it needs to. While the voltage on a module may hit 16-17V during
this step, they won't all do so, so you needn't open the voltage limit
up to 16-17V x the number of modules. Adjusting the charger settings
manually at the start of the final I step and back to normal afterwards
will probably get old real quick if you try doing it on every cycle.
Probably doing it once every few cycles, or perhaps just once a week may
be enough to keep the batteries from deteriorating.

As Ralph notes, Optima's recommendation of 1hr @ 2A is based on the
assumption of an 80-100%DOD discharge, so it is reasonable to scale back
the duration if you are doing shallower cycles.

Note that the Orbital recommendation is 2hrs @ 1.5A, and I would suggest
observing this as a starting point rather than Optima's recommendation
since you are using Orbitals.

Cheers,

Roger.

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Discussion Starter · #19 ·
Yes, 15V is what I meant to type. I Fat Fingered that one.

My last pack died early, the seven batteries that were in the best
condition were the ones up front that the regs got removed from. I was
alwasy wondering if I chronically undercharged the ones with regs or if
they had gotten hot being inside the cabin. I sent them back for
analysis and never did get an answer. But they, Exide, replaced the
whole pack under warrantee!!!

I just want to make sure I am treating these correctly.

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Discussion Starter · #20 ·
Re: [EVDL] New Optima Pack

Would 1amp for 4 hours do the same as 2A for 2 hours? is it just about
amphours? I am thinking 2A for an hour is just a maximum to get last 4Ah
in there or ~last 10%.?

If so, that prevents the high voltage spike that trips off the charger
or triggers the regulators.

I have taken to leaving my charger on for 8 hours at .7A once a week and
it really seems to help. But I drive almost every day, so I need a good
mid week solution and something more automatic than PFC and regs then.

The statement about 13.1 after 8 hours of sitting fully charged is
interesting as that would be 314V and mine is ussually around 305V.


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