T-Pain Is On A Boat: Re: [Electric Boats] When good batteries go bad

Thursday, July 16, 2009

Re: [Electric Boats] When good batteries go bad

The people at Glacier Bay know a lot. You might give them a call. j

On Thu, Jul 16, 2009 at 12:47 PM, aweekdaysailor
<aweekdaysailor@yahoo.com>wrote:

>
>
> OK, short of tossing 12 batteries...I am experimenting with selectively
> replacing bad batteries in my pack.
>
> By "bad" I mean a battery that will accept a full charge, but discharges
> well in advance of the other batteries in the string (so...it's not a
> shorted cell which I think is an automatic toss, but rather likely plate
> degradation)
>
> I have already tried de-sulfating - I can see improvement, but not enough.
>
> My theory is...if I pair a new battery with the worst of the pack (in
> parallel) then that unit now acts like a medium-good battery in relation to
> the others (the good battery will be trying to continually charge the bad
> one during discharge - conversely during charge the good battery will be
> helping the charger see it's "full" and go into float). I think I still
> won't get the full pack amperage, but some "average" value determined by the
> weakest pair.
>
> There are lots of warnings about not doing this - but no clear
> explanations.
>
> Any battery gurus care to comment on the strategy?
>
> I've split my 12 into 2 separate banks now - 1 bank of 4 batteries (all
> aged) and 1 of 8 (2ea in parallel for the above balancing). I'm using my old
> red Perko switch so I can combine or run each bank independent. This allows
> me to isolate and test "bad" batteries individually and re-shuffle the packs
> to find the proper balance.
>
> Also...my chargers do not have an equalization setting. Short of buying one
> that does have one - is there another way to do an equalization? Maybe that
> can further help the weak batteries.
>
> Am I doomed to visiting Walmarts return counter?
>
> Thx
>
> -Keith
>
>
>

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