The M18 REDLITHIUM XC Extended Capacity battery is designed with superior pack construction, electronics, and performance to optimize work per charge and work over pack life. It offers 4.0 amp-hours of runtime. With built-in Milwaukee durability, this battery runs cooler and performs in climates below 0°F/-18°C. Managed by Milwaukee’s exclusive REDLINK Intelligence, the battery features overload protection to prevent you from damaging your cordless power tools in heavy-duty situations, while the discharge protection prevents cell damage. The temperature management system and individual cell monitoring help maximize battery life. Use this extended-capacity battery to power your Milwaukee M18 cordless power tools.