This Stihl's AK 30 is the most powerful battery in the STIHL AK Series, providing up to 80% longer run times than the AK 20 and allowing users to get more work done on a single charge. This Lithium-Ion battery is lightweight at 2.9 lbs. and features a good power-to-weight ratio using 36 volts. It is compatible with any STIHL battery charger.