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
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.
>
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