The NP-11H Nickel-Metal Hydride battery is the exact replacement for the old design Sony NP-11 (Nickel-Cadmium) battery. It contains newer design cells that hold a stronger charge and then release it with a flat discharge rate. This means the battery stays at it's 9.6 volts to the very end. Plus, it has no memory. Charge it at any discharge stage and it will come back to a full charge. The old cadmium batteries couldn't do that. Rated at 2100 milliamp hours, it's over twice as powerful as the old NP-11 and it's 25% lighter. You use the same charger, because it is the battery that tells it when it's time to stop charging. The same internal protecter that prevents shorts and overheating also breaks the circuit for the charger when the cells inside reach their full charge, just the way Sony intended. Recommend only for use with the chargers that came with the Betamovies because rapid charging may tend to shorten it's life expectancy. You can recycle your old NP-11 and NP-11H batteries, click here.