18v lxt, lithium-ion, 5.0ah battery, integrated led battery charge level indicator allows user to monitor battery charge, reaches full charge in 45 minutes or less, compatible only with star protection tools, indicated by the star symbol &/or yellow battery receiver under the tool, battery delivers consistent power & run time in extreme temperatures, equipped with star protection computer controls to protect against overloading, over discharging & over heating, impact resistant outer case & shock absorbing inner liner are engineered to protect the battery, 16 contact terminals maintain a constant connection with the tool to help prevent power loss or fluctuation, even during high vibration applications, battery resists self discharge & remains ready for use even after long periods of storage.