Since 1931, Panasonic has been a leading manufacturer of battery technology and innovation. In 2005, we set out to develop a new type of Nickel Metal Hydride rechargeable battery that would literally change the way people live, work, and play. The result was envelop, a Ni-MH rechargeable battery created with a very simple idea in mind; provide a common energy source that can be reused, over and over again. This looping energy became known as envelop. Today, envelop battery cells are recognized by millions of consumers worldwide as the industry’s premier rechargeable battery. envelop pro high-capacity Ni-MH, low self-discharge batteries utilize Panasonic advanced rechargeable battery technology, allowing them to be recharged up to 500 times. envelop pro batteries deliver consistent power performance, maintain 85% of their charge for up to one year (when not in use), come pre-charged using solar power (at the factory) and are ready to use out of the package. They also have extreme temperature performance down to -4 degrees Fahrenheit. These envelop pro high-capacity rechargeable AA batteries are perfect for camera flash units, flashlights, gaming devices, headlamps, wireless keyboards and mice, toys, remote controls, and thousands of other household devices. The Panasonic CC17, 4-position Ni-MH battery charger is a convenient way to recharge any combination of up to four AA or AAA Ni-MH envelop pro, envelop, or conventional Panasonic Ni-MH rechargeable batteries. The CC17 charger also features 4 LED charge indicator lights and a retractable AC plug.