On 17-Mar-2005, Dave Hall wrote:

Surprisingly this is exactly what my 18 volt XRP DeWalt drill manual
says.("As soon as you detect that the tool performance is diminished,
it's time to recharge.")

There is always some ambiguity in what "fully discharge" means.
To some, that means wipe out any power the battery may have, to others,
it's drain until it is not particularly useful. Draining the battery
of all power will destroy it. Discharging it until it's not useful
(as in "performance is diminished") won't damage it.

Mike