The Metabo Slide LiHD (Lithium-Ion High Density) Battery Packs provide the ultimate performance and extremely long application with minimal temperature generation. Ultra-M technology delivers intelligent battery management for long-lasting battery packs. Electronic Single Cell Protection (ESCP), protects each and every battery cell from discharging completely and from overcharging, for extremely long battery life. Patented AIR COOLED charging technology, the battery pack is cooled by a fan in the charger - for shorter charging time and longer service life. Compatible with all Metabo 18V machines and chargers that accept slide-on-type batteries.