The Racers Edge Sure Charge 1200 uses advanced peak prediction circuitry that calculates exactly when the peak will occur, when your battery is full, and stops fast-charging at exactly that point. Peak prediction technology prevents damage to the battery pack from overcharging. The SC1200 is a safe, reliable, & inexpensive way to peak all your Nimh and Nicd battery packs. Plus with AC/DC capability you do not need an external power supply to charge at 4amps! DC wired for field use as well.