[Shop-talk] 18v battery dead? Reviveable?

[Mark Andy]

Howdy,

On Wed, 14 May 2008, Randall wrote:
>> Anyway, now the battery won't charge.  I seem to recall
>> something somewhere saying that if you drain it all the way
>> dead, the charger won't recognize the battery on there and
>> won't try to charge it?
>>
>> Is that right?  How do I convince it to try charging anyway?
>
> My Ryobi charger is like that.  To work around it, put a little charge 
> into the battery some other way.  If you can figure out which terminal 
> is which, an ordinary 12v automotive trickle charger will probably do. 
> I use my adjustable bench supply.

So, I gave this a shot tonight.  Checked polarity on a charged batter with 
a meter, then hooked up a 12v jumper pack to the dead battery pack and 
left it for a while.  After a half hour or so, tossed it back onto a 
charger and the light came on saying it was charging!

Battery seemed to work after charging, but of course I don't know if 
runtime has been affected.

Anyway, thanks!

Mark