These Ni-Cd/Ni-MH battery chargers have timer control to protect the battery against ovrcharging. Its recommended a charger is seleted with a charge current less than 0.25C (C = battery pack capacity). Please advise your battery capacity when inquiring.
The following formula is used for calculating the fast charging time: Fast charging duration (hr) = battery capacity x 1.4 / charging current
Optional fuse or polyswitch can be added for reverse polarity rotection, short circuit protection or over load protection