For use with the Stihl Compact Cordless System, the AK 20 is a 36v rechargeable lithium battery with a capacity of 180 Wh. It features an LED charge level indicator. Compatible with AL 101, AL 300 & AL 500 chargers. Charged to 100% with AL 101 charger: 205 mins Charged to 100% with AL 300 charger: 60 mins Charged to 100% with AL 500 charger: 60 mins Specification: Battery Type: 36v Lithium-ion Battery Capacity: 5.2 Ah / 180 Wh Weight: 1.3kg Warranty: 2 Year