STIHL® AP 500 S Lithium-Ion BatteryDescription: As the most powerful AP System battery, the AP 500 S allows professionals to tackle larger jobs with more power than other batteries in the AP System. Built with STIHLs exclusive power laminate cell technology, the AP 500 S gives you up to a 2,500 cycle life. The AP 500 S offers an improved power to weight ratio and features 40% more power output and 20% more capacity than the AP 300 S. The AP 500 S is compatible with most tools in the AP