Welltop&reg; 4Pcs 3.7V 14500 2000mah Rechargeable Lithium Battery with Battery Charger 14500 protected batteries with 4.2 volts max voltage and 3.7 volts nominal voltage. 14500 Li-ion Rechargeable batteries Capacity: 2000mAh Capacity: 2000mAh, Voltage: 3.7V