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Discussion Starter #1
Re: [EVDL] New Optima Pack/Applied to Orbitals?

Using this logic what would be the optimal setting for a new set of
18 Exide Orbitals? My PFC 30 is set to a finish voltage of about
259.2V or 14.4V each. The rudman regs are set at 14.8V. At the end
of the charge the draw fluctuates between .6 and 1A at the most-
averaging in the middle. How long should the charger be held here to
insure a proper equalization and how long past a certain amp draw?
In other words, once the pack draw in amps is at (x) amps then the
charge should continue at (x) amps for (x) time. What are the x's,
not sure if my timer needs to be increased or if the finish voltage
should be lowered or kept the same with a longer charge. It has been
mentioned to me that the finish Amp should be .5 and if that is true
what is the best duration?

Mark


Roger Stockton wrote:

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

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Discussion Starter #2
Re: [EVDL] New Optima Pack/Applied to Orbitals?

Mark Dutko wrote:

> Using this logic what would be the optimal setting for a new set of
> 18 Exide Orbitals? My PFC 30 is set to a finish voltage of about
> 259.2V or 14.4V each. The rudman regs are set at 14.8V. At
> the end of the charge the draw fluctuates between .6 and 1A at
> the most-averaging in the middle. How long should the charger be
> held here to insure a proper equalization and how long past a
> certain amp draw?

With this setup you are performing an IU charge profile, not the
recommended IUI profile. Your charger will hold the voltage at an
average of 14.4V/module while the regs ensure that no module exceeds
14.8V (for long).

If you want to do a final I step, you would need to disable the regs and
alter the voltage and current settings on the PFC30 to allow it to push
a constant current nearer the recommended 1.5A through the pack. This
requires raising the voltage setting and then reducing the current limit
to 1.5A. And, of course, remembering to set it back to normal and
re-enable the regs afterwards so you don't abuse the pack on the next
charge cycle.

Generally, the philosophy on which regs are based is that it is most
critical to battery life to never let the module voltage exceed some
safe level at anytime, and so instead of a constant current finish step
to apply the required overcharge, reg users would normally just let the
charger continue until a suitable amount of time after hitting the
voltage limit. "Suitable" in this case usually means for some amount of
time after all regs are blinking at about the same rate, which indicates
that all batteries have been allowed to reach the set maximum module
voltage.

> In other words, once the pack draw in amps is at (x) amps then the
> charge should continue at (x) amps for (x) time. What are the x's,
> not sure if my timer needs to be increased or if the finish voltage
> should be lowered or kept the same with a longer charge. It has been
> mentioned to me that the finish Amp should be .5 and if that is true
> what is the best duration?

I interpret your end-of-charge charge behaviour to indicate that your
batteries are presently tapering down to about 0.6A vs the 0.5A that has
been suggested to you. You could try extending the timer to see if the
current comes down any further or not, but I consider anything <1A to be
normal.

The nature of the reg operation is that they bypass a different and
random amount of the charge Ah around each module in the string, so it
is difficult to determine just how many Ah of overcharge each module may
have received during X hours of finish.

There is also debate over whether having the regs clamp the module
voltages allows the modules to get the same benefit as they would from a
similar amount of Ah applied without the regs.

Cheers,

Roger.


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Discussion Starter #3
Re: [EVDL] New Optima Pack/Applied to Orbitals?

Since it would be a real pain to disable the regs I assume keeping
them at 14.8 would be a safe measure and charging longer below 1A is
safe for the pack and will help top off the lower batteries? How long
can the charge cycle be safely below 1A at 14.4 per battery with regs
at 14.8?

I set the finish voltage a bit lower to keep the regs from getting
hammered before. I also can monitor each battery with my paktrkr.


Thanks


Mark



Roger Stockton wrote:

> Mark Dutko wrote:
>
>> Using this logic what would be the optimal setting for a new set of
>> 18 Exide Orbitals? My PFC 30 is set to a finish voltage of about
>> 259.2V or 14.4V each. The rudman regs are set at 14.8V. At
>> the end of the charge the draw fluctuates between .6 and 1A at
>> the most-averaging in the middle. How long should the charger be
>> held here to insure a proper equalization and how long past a
>> certain amp draw?
>
> With this setup you are performing an IU charge profile, not the
> recommended IUI profile. Your charger will hold the voltage at an
> average of 14.4V/module while the regs ensure that no module exceeds
> 14.8V (for long).
>
> If you want to do a final I step, you would need to disable the
> regs and
> alter the voltage and current settings on the PFC30 to allow it to
> push
> a constant current nearer the recommended 1.5A through the pack. This
> requires raising the voltage setting and then reducing the current
> limit
> to 1.5A. And, of course, remembering to set it back to normal and
> re-enable the regs afterwards so you don't abuse the pack on the next
> charge cycle.
>
> Generally, the philosophy on which regs are based is that it is most
> critical to battery life to never let the module voltage exceed some
> safe level at anytime, and so instead of a constant current finish
> step
> to apply the required overcharge, reg users would normally just let
> the
> charger continue until a suitable amount of time after hitting the
> voltage limit. "Suitable" in this case usually means for some
> amount of
> time after all regs are blinking at about the same rate, which
> indicates
> that all batteries have been allowed to reach the set maximum module
> voltage.
>
>> In other words, once the pack draw in amps is at (x) amps then the
>> charge should continue at (x) amps for (x) time. What are the x's,
>> not sure if my timer needs to be increased or if the finish voltage
>> should be lowered or kept the same with a longer charge. It has been
>> mentioned to me that the finish Amp should be .5 and if that is true
>> what is the best duration?
>
> I interpret your end-of-charge charge behaviour to indicate that your
> batteries are presently tapering down to about 0.6A vs the 0.5A
> that has
> been suggested to you. You could try extending the timer to see if
> the
> current comes down any further or not, but I consider anything <1A
> to be
> normal.
>
> The nature of the reg operation is that they bypass a different and
> random amount of the charge Ah around each module in the string, so it
> is difficult to determine just how many Ah of overcharge each
> module may
> have received during X hours of finish.
>
> There is also debate over whether having the regs clamp the module
> voltages allows the modules to get the same benefit as they would
> from a
> similar amount of Ah applied without the regs.
>
> Cheers,
>
> Roger.
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #4
Re: [EVDL] New Optima Pack/Applied to Orbitals?

Mark Dutko wrote:

> Since it would be a real pain to disable the regs I assume keeping
> them at 14.8 would be a safe measure and charging longer below 1A is
> safe for the pack and will help top off the lower batteries?
> How long can the charge cycle be safely below 1A at 14.4 per battery
> with regs at 14.8?

You're probably safe leaving them like this for up to several hours, but
you want to leave them for the least amount of time that you can. You
might start out trying to leave them for perhaps an hour longer than you
presently do, and see if the current drops any further. If it doesn't,
then there isn't much point increasing the time further, but if it does
drop more than 0.1-0.2A, try increasing the time another hour.

If you can log the charge current with the PakTrakr or an E-Meter, you
can see how long after the pack hits the 14.4V/module level that the
current stops decreasing significantly. I'd set the timer so that the
charger runs for about 1hr more after this point. It's not very
precise, but it is better than nothing.

> I set the finish voltage a bit lower to keep the regs from getting
> hammered before. I also can monitor each battery with my paktrkr.

Yep, that's the way to do it. If you set it at the reg level or higher,
then you are guaranteeing that all the regs will be locked on solid
before the charger relents (of course if you've got regbus operational
the regs have the ability to issue an SOS and force the charger to back
off).

Cheers,

Roger.

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Discussion Starter #5
Re: [EVDL] New Optima Pack/Applied to Orbitals?

Thanks- I was thinking the same but not sure...

Mark


Roger Stockton wrote:

> Mark Dutko wrote:
>
>> Since it would be a real pain to disable the regs I assume keeping
>> them at 14.8 would be a safe measure and charging longer below 1A is
>> safe for the pack and will help top off the lower batteries?
>> How long can the charge cycle be safely below 1A at 14.4 per battery
>> with regs at 14.8?
>
> You're probably safe leaving them like this for up to several
> hours, but
> you want to leave them for the least amount of time that you can. You
> might start out trying to leave them for perhaps an hour longer
> than you
> presently do, and see if the current drops any further. If it
> doesn't,
> then there isn't much point increasing the time further, but if it
> does
> drop more than 0.1-0.2A, try increasing the time another hour.
>
> If you can log the charge current with the PakTrakr or an E-Meter, you
> can see how long after the pack hits the 14.4V/module level that the
> current stops decreasing significantly. I'd set the timer so that the
> charger runs for about 1hr more after this point. It's not very
> precise, but it is better than nothing.
>
>> I set the finish voltage a bit lower to keep the regs from getting
>> hammered before. I also can monitor each battery with my paktrkr.
>
> Yep, that's the way to do it. If you set it at the reg level or
> higher,
> then you are guaranteeing that all the regs will be locked on solid
> before the charger relents (of course if you've got regbus operational
> the regs have the ability to issue an SOS and force the charger to
> back
> off).
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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