Originally Posted by steveknight
but you don't know how well the cells are charged or if they are fully charged. you won't get the full life or runtime out of them.
Given a batteries rated capacity, the efficiency of recharging (~66% with Nicads) and the output of ones charger, it's not to difficult to calculate the time required. While not dead on, if one is consistent and keeps note of the performance, one can obtain upwards of a thousand cycles from the battery.
And when it's spent, I'll get another for $20-$30.