Today's batteries are a little different. They no longer need to be run
down from time to time. The memory effect is a thing of the past. They do
need to be kept charged. The set I got had a three station charger for
mounting on the wall keeping all three batteries charged. They are all over
three years old and I have not noticed any decrease in capacity.

Sums up my experience with batteries also...My trimmer is older then 3
years and its not a GOOD one either...cheap sears 9 v

Bob G.