Metabo 18V, 5.2Ah Li-Power Battery Pack with "AIR COOLED" ULTRA-M Technology: Intelligent battery management for long-lasting battery packs with a 3-year warranty. Patented "AIR COOLED" charging technology. Permanent electronic single-cell monitoring (ESCP) during charging for an exceptionally long service life. Processor-controlled charging and discharging management. Capacity indicator for continuous monitoring of the charge level. No memory effect. Long shelf life with virtually no self-discharge. Excellent environmental properties. Technical data: Battery pack voltage: 18V. Battery pack capacity: 5.2Ah. AIR COOLED: 1