Sofirn 21700 4000mAh Battery 40A 3.7V 10C Rechargeable Lithium Discharge 21700 Cell Poweful High Drain Batteries for Flashlight Battery Information Battery type:21700 4000mAh 10C Power Battery Battery Minimum Capacity:4000-3900mAh Battery Discharge Current:40A Battery Capacity:4000mAh Battery Voltage:3.7V Sofirn Battery Feature High energy density/ Long cycle life/Wide application/High discharge rate Safety: Excellent abuse tolerance and environmentally friendly Life: Excellent calendar and cycle life Universal Model multi Applications Electric vehicle, Electric Bicycle, Tricycle, scooter, golf trolley, cart, wheelchairs, instrument, Solar supply system,solar panel, energy storage, electric tools, power tools, LED Flashlight/ lighting,toys, inverter, household appliances and emergent device area, etc.