STIHL AK 20 Lithium-Ion BatteryDependable battery with increased performance over the previous model. The redesigned AK 20 battery features increased performance over the previous model and runs at full power over the entire battery run time. Easy to read LED display lights indicate battery charge. Compact and lightweight, this battery provides optimal power and performance for your AK System tools with minimal loss of charge during storage. Ideal for select AK System tools, the AK