*18V LXT Lithium-Ion 4.0 Ah battery reaches a full charge in 40 minutes or less *Battery delivers consistent power and run time in extreme temperatures, even in winter (-4-Degree F/-20-Degree C) *Impact-resistant outer case and shock-absorbing inner-liner are engineered to protect the battery *Sixteen contact terminals maintain a constant connection with the tool.Battery resists self-discharge and remains ready for use even after long periods of storage *Central Processing Unit (CPU) in battery communicates with charger to analyze battery and charge according to its unique condition