M18 Compact REDLITHIUM Battery. Delivers more runtime, power and speed than standard lithium-ion batteries. The M18 Compact REDLITHIUM Battery is designed with superior pack construction, electronics and performance to optimize work per charge and work over pack life. It offers 1.5 amp-hours of runtime. With built-in Milwaukee durability, this battery runs cooler and performs in climates below 0F/-18C. Its compact, lightweight design fits in tight work spaces and reduces user fatigue. 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 compact battery to power your Milwaukee M18 cordless power tools.