Re: Charging Un-matched Li Polies in Parallel?

On Sat, 25 Mar 2006 06:46:37 -0600, Wan <Wan.258b4b@xxxxxxxxxxxx>
wrote:


Hi, I have three TP Li Poly batteries 3S 2100 mAh that have been
discharged to varying degrees of voltage. It sometime takes about 30
minutes to recharge individually, depending.

You should not charge Lipoly batteries in 30 minutes. They should not
be charged at more than a 1c rate , which would be one hour , or
slightly more. In your case the charge rate should be no more than
2100 ma.

You also need to be ...very... concerned about the... balance.. of the
individual cells. If they are unbalanced they need to be charged at a
very slow rate.
In most cases a 12 hour charge would be OK.
One of the idications of an unbalanced pack is if the volage per cell
is less than 3.3 volts. In your case the pack should be no lower than
9.9 volts. They can still be unbalanced if they are not this low in
voltage , but this is the most common symptom.

I wonder it they could be connected in parallel and recharged? Or would
the batteries be un-balanced? If this could be done, would the charging
time be shortened?

Don't charge more than one pack at a time . Multiple packs can be
charged in parallel but only if all cells and packs are balanced.


I would recommend that you go to here before you do anything .

http://www.thunderpower-batteries.com/html/charging.html
This is a link to a pamphlet on charging Lipoly batteries.

Wan

Ken Day
.

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