# How to test individual cells in a battery pack



## watcher (Sep 4, 2006)

Short version of a long story. I picked up a set of Ryobi tools with 2 batteries in a deal. Both batteries had problems so I bought new ones. Monday a friend gave me his old Ryobi drill and flashlight with 3 batteries and all 3 batteries are no good. Now I have 5 no good batteries.

I'm sure out of 5 battery packs there must be enough cells in them I can make at least one working battery.

Now the question; How do I test the individual cells to see if it will take and hold a charge?


----------



## Roadking (Oct 8, 2009)

I usually disassemble the packs (they are usually "sub c" cells). Take the cells and put in my regular battery charger; the type that take AA, C D whatever. Leve them in for a bit (sometimes overnight), and then test them with a voltmeter. Usually, by replacing one or two bad sells, you can get the pack back. Now, just resolder the pack back together...remember to note the orientation of the cells before disassembling them...
Matt
PS, Ryobi usually uses panasonic cells, and often the problem is corosion...the cells are usually paper wrapped.


----------



## Jim-mi (May 15, 2002)

A short term fix is zap the whole bat with a higher voltage.
I put 24vdc from my home system to a 12vdc Bosh bat .. . .(two seconds) then put the regular charger on it . . . . .very short fix.

Of course I had to get a new one in the long run......


----------



## mightybooboo (Feb 10, 2004)

My new battery charger reconditions nicad and nimh by running them a charge,a disgharge then repeat,my worse one took 7 cycles,it went from 1 ma/hr,thats right,ONE,to 38,78, 138 and so on til it got up to 1648 on a 2000 ma/hr battery. Pretty cool,might try doing that manually,but run it real dead between charges,thats all it does.

Pretty nice BTW!Got mine for 29.99 when it was featured at survivalblog,they since upped the price at amazon.I realize this isnt a tool charger,just FYI
http://www.amazon.com/Crosse-Techno...OV50/ref=sr_1_1?ie=UTF8&qid=1297885505&sr=8-1


----------



## Darren (May 10, 2002)

That's the charger I use on all my rechargeables. I just wish it did others beside the AA and AAA batterys.


----------

