The Titanium V4000 Ultra Fast Battery Charger is truly a convenient and powerful charger that is compatible with NiMh/NiCd AA and AAA batteries. Charge either two or four batteries at a time without having to worry about overcharging your batteries. The V4000 features various safety features to keep your batteries cool and charged. The lightweight and portable V4000 is equipped with a microprocessor controller for fully automated charging, as well as micro burst charging, keeping your batteries cool. Short circuit and overload protection prevents from internally damaging the circuitry. A special on-board battery conditioner reconditions weak batteries for maximum recharge capacity. Revive batteries using the unique "CPR" feature, as it uses a special voltage to bring your cells back to life.