|I have a Craftsman C3 tools set and I bought a lithium ion battery and charger for them and they are fantastic! They hold a much larger charge and they have a little light to tell you when the charge is good, fair or low.
They hold a charge incredibly well, so I never have to worry about going to do a quick job and fidning just a dead battery. They don't have to be completely drained before recharging like the old Nickel cadmium (nicad or ni-cad) batteries; they don't have any memory issues. They don't have any problems being kept fully charged.
They battery and charger was $80 and this new charger will charge the older batteries too -- and a little faster!!