The energizer extreme rechargeable aa 2300mah battery 4 pack offers you an aa rechargeable battery that delivers a long lasting performance and the robust cycles you need with the added convenience of excellent charge retention this is a battery that holds its charge for up to 1 year when not in use the energizer extreme is the reusable high performance solution for all occasions and power demanding devices which means you save money and reduce waste by replacing less batteriesrrfeature