Lithium-Ion batteries are longer lived than conventional batteries and do not require replacement as often. This E6400 6cell Battery FU457 is a Lithium-Ion Primary Battery from Dell and helps you power up your system for business trips and vacations. With a capacity of 56WHr this battery lets you work seamlessly when you are on the move. This product has been tested and validated on Dell systems. It is supported by Dell Technical Support when used with a Dell system.