Stihl AP 500 S BatteryAP 500 S BATTERY: LITHIUM ION 337 WH BATTERY High capacity 36 V, 8. 8 Ah Lithium Ion battery. The AP 500 S is the most powerful AP battery from STIHL. Featuring power laminate technology which means it has double the number of charging cycles of a typical STIHL AP system battery with cylindrical cells. With approximately 253 charging cycles per year (253 working days, excluding weekends and bank holidays in UK) the battery will last close to 10 years