Cordless Alliance System – one battery for everything. This product is part of the Cordless Alliance System (CAS), the cross-manufacturer 18-volt battery system from leading power tool brands. This battery system already allows you to easily combine more than 300 machines, battery packs, and chargers from a wide variety of manufacturers. Buy only what you really need and save resources and money with the CAS System from and with Metabo! • Intelligent battery management for long-lasting battery packs • Patented "AIR COOLED" charging technology • Permanent electronic single-cell protection (ESCP) during charging for an exceptionally long service life • Processor-controlled charging and discharging management • Capacity indicator for continuous monitoring of the charge level...