... 2V 1500mAh 18650 Rechargeable LiFePO4 Battery, LiFePO4 Battery Pack for Power Tool, RC Toy, Electric Vehicle 3.2V 18650 ... utilizes natural, phosphate based material and offers the greatest combination of performance, safety, cost, reliability and environmental characteristics. ... half hour10. Perfect for building up battery pack for medical equipment Back-up or EPS Emergency Power, Good performance ...