The Toshiba Primary Battery Pack is a 6-cell, rechargeable, Lithium Ion battery designed to work with select Toshiba Portege R500 series portable computers. Used as either a spare or replacement battery, this battery pack meets or exceeds the specifications of the original battery that came with your notebook. It interfaces with the Toshiba Power Saver Utility on the notebook which features a charge indicator to help you monitor the available power.Take your office on the road without sacrificing performance, productivity or convenience with Toshiba notebook battery packs. Battery power gives you the ability to use your computer around the house, on campus, in the office, and when you travel either on business trips or vacation. Enhanced battery life helps you stay connected and be productive wherever your work takes you. Add extended power capabilities to your portable computer with an additional battery pack now!