The 18V Metabo LiHD Starter Kit 5.5 Ah + 3.1 Ah is designed as a base kit for maximum flexibility to build your own cordless kit. The starter kit includes one (1) 5.5 Ah LiHD full-size battery, one (1) 3.1 Ah LiHD compact battery, one (1) charger, and one (1) heavy duty canvas tool bag. The 5.5 Ah LiHD full-size battery pack provides extreme runtime for less downtime on the jobsite while the 3.1 Ah LiHD compact battery pack produces more power in a compact and lightweight pack providing runtime equivalent to most competitors’ full size batteries. The LiHD high density battery is the next evolution in Li-Ion technology, amplifying the power transferred to the motor producing more runtime, more power, and longer service life. LiHD utilizes revolutionary high density battery cell technology combined with the highest quality materials and heavy duty high current components to deliver significantly more power and extreme runtime for high demand applications that were previously not possible with 18V cordless tools. The LiHD battery incorporates Ultra-M Technology, the most advanced and intelligent cordless platform with complete integration of the tool, battery and charger. Electronic single cell protection prevents damage to the cells from over charging or over discharging. Overload protection on both the tool and the battery pack guard against overheating to extend the life of the system, while the patented air-cooled charging system quickly cools the battery allowing for up to 30% faster charge times while significantly increasing the number of recharges over the life of the battery. The LiHD batteries are 100% compatible with all Metabo 18V cordless tools and chargers. The LiHD battery features built-in shock resistance to stand up to the toughest demands and a 4-LED capacity indicator to stay productive on the jobsite.