BATTERY PACK LIHD 18 V ? 5.5 AHLiHD battery packs for ultimate performance and extremely long application with minimal temperature generationUltra M technology: Intelligent battery management for long-lasting battery packs with a 3 year guaranteePatented ?AIR COOLED? charging technologyPermanent Electronic Single Cell Protection (ESCP) when charging, for particularly long life.Processor-controlled charge and discharge managementCapacity display with almost no self-dischargeCapacity display with almost no self-dischargeOne battery pack for everything. 100% compatibility with all 18 V machines and chargers of the CAS partners: www.cordless-alliance-system.com