Discharging to 1v vs 1.2 v can reverse polarity on a old pack. RC car
hobbiests that spend 10+$ a single cell and want performance for races
use very expensive chargers-conditioners that optimise performance. Tool
owners risk more damage on a complete discharge, and Tools dont have
smart electronics yet .
This may be greatly due to companys profit margins on new packs. These
days the replacement packs subsidise the tools.
A slower charge is better as in your car lead acid battery, a 200A
charger cooks cells. Although chemistry is different for Nicad and NiMh,
as cells membranes get thinner with higher Amp capacities cells get more
I have a 1986 Makita pack that functions and I used commercialy, and 5
more pre 90 packs. Battery life is more dependant on the user than the
pack. Not using or charging a hot pack, 24 hr rest, not over discharging
or charging till voltage drop and heat is generated are some of the
most important things manufacturers wont tell you. Their big profit is
in you buying a new pack.
A fast 15 min charge just does not go with my logic . Sanyo and
Panasonic make the best batteries. A 1 hr charge has the logic of being
more " cell friendly" than a 15 min charge, regardless of the Tool
makers instructions. My Makitas are 1 hr. B&D 4-6.