These Smart Q-Chargers are specially designed to safely and quickly (Q) recharge our our NiMH battery packs; automatically sensing the packs' voltage, it adjusts its current (AMP) output accordingly and later automatically shuts itself off when the pack is fully recharged. Equipped with a smart LED that indicates charging condition, it is safety fused and comes with the most common agency approvals. In addition, it has a switch for either 110 or 220 Volt A.C. (50 or 60 Hz) supplies and a wide variety of International A.C. input cords are available. Use only Rabbit Tool U.S.A. approved battery chargers to recharge our battery packs as failure to do so will instantly void all our warranties, may destroy your battery pack, the controller and possibly cause bodily injury & or property damage as well as possible fire and explosion. For most people, topping off the battery pack with this Q-charger during lunch hour is enough to get them where they need to go.