Months ? Nicads ? Wet Cell , in a plane ... OK .
Dry types? from da store , for your drill ? naaaaaah .
50% in a 20 days !!

Li-Ion is high rate power , loss can be 1% /month .
priced out of reach , ..... I tossed all my Nimh !
Just too good to be intimadated by price !
But they die if too much amps charge above the 3.65 vdc level .

All batteries will float if the amps are very low .

( BTW Harbor Fright tiny driver $20 , w/ Li-Ion has no greater than
a 1 aH single cell ) .


George E. Cawthon wrote:
Jim Yanik wrote:
Dan_Musicant wrote in
:

I have a Panasonic 12v (NiCads) cordless drill/driver with 2 batteries
and it seems to me that the batteries aren't holding a charge very well.
They are around 3-4 years old, lightly used. They seem to charge too
quickly. If I leave them in the charger after the charger shows them as
fully charged and let them trickle charge, will that top them up? I
haven't been doing that.

some chargers are designed to be able to leave the pack in,some are not.
You need to check your manual.
Is this a loss of capacity of the batteries? Is there some way I can
restore the capacity of the batteries? Any experience with these? Thanks
for any ideas, info, suggestions, etc.

Dan

It's been my experience that for longest life,NiCds are best used
often.(use it or lose it)
Once you start storing them for long periods,their life decreases.
NiCds also have a self-discharge rate;just sitting in storage,they
discharge on their own.



Probably right about the use or lose it.

If you don't use them much you need to keep
checking the voltage at least once every 1-2
months and make sure the voltage doesn't drop
below 12V. Full charge on a 12V NiCad is about
14V, but that degrades quickly to about 13V and I
check the voltage when charging and stop before it
reaches 14V. Overcharging is the number one cause
of batteries going bad.