I have a Black and Decker 18v cordless drill (the one with the "slide in" battery. I've checked the voltage of two batteries I have and they are both fully charged, but when I try to use the drill I can easily stop it from turning with just my hand, and then it acts like the battery is dead or dying but the batteries are up
whats with that!?...anybody know??
thanks!

almost giving up, October 2008

The previous answer says this applies to batteries 1-2 years old

The memory effect applies to ALL rechargeable batteries

New types are much better but IT STILL APPLIES to ALL batteries
(Ignore what manufacturers say that it does not apply)

Eventually they will all die.

NA, August 2009

The batteries have had it. They are not holding a charge

The fact that they read full voltage is not relevent, as you are taking the reading with no load on the drill. As soon as you put the batteries under a load (by switching on the drill and holding) you lose whatever charge the battery managed to hold during charging, so the battery voltage drops and the drill does not function.

If you then remove the batteries you will probably read full voltage again.

THis is a problem after repeatedly charging ALL rechargeable batteries (but some are better that others)

THe WORST thing you can do is to leave them on trickle charge, or charge them again before they are FULLY discharged. (the fact that the drill does not function DOES NOT mean the batteries are FULLY discharged, its just means that the battery voltage on load is too low for the drill to function).

The best thing you can do is to leave the drill switched on (as if drilling) for several hours (even though it may not be turning), BEFORE recharging the battery.

NA, August 2009

I have just had the same with my Bosch drill, I had to replace the batteries, (not cheap.) If they are the older style batteries about 1-2 years old then you will have to replace them, as this type has a memory. So if you fully charge the battery and use it for a while with out completely running it down, then you recharge it it causes problems to the cells.

The same can be said foe leaving these items in a cold place like the garden shed, where the temp fluctuates to much and causes undue stress on the cells.

If you need more info try me at our store.

http://www.toolvolt.co.uk/powertools/expert.php

Joe Dybowski, January 2009