In article om,
Andrew Williams wrote:
The traditional way to erase battery memory is to deep-cycle the
battery. For a drill/driver, I would use it until the thing hardly
turns at all, then find a way of clamping the trigger down so as to
completely drain the battery. You want to get it as close to 0VDC as
possible. After that, fully charge the unit and see if the memory has
been erased.



This is indeed the traditional way and it is also NOT a good idea. The
"memory effect" is pretty much a myth for multicell nicads used in
cordless power tools. Letting the batteries fully discharge is also
potentially harmful to the battery. When all the cells are fully
discharged, it becomes possible for one or more of them to go into a
reversed polarity state. Once this happens that cell becomes
permanently useless. For a good quality cordless tool with a "smart"
charger (most any DeWalt, Makita, Milwaukee, etc.) the best place to keep
a battery is in a plugged-in charger. For cheaper cordless tools (like
Harbor Freight's) with a "dumb" charger, remove the battery after the
recommended charging time.
--

Larry Wasserman Baltimore, Maryland