Ni-MH USB AA Rechargeable Battery Datasheet as below: 1) Easily charged from any USB power source 2)Low Self Discharge (LSD) type NiMH cells 3) Up to 500 charge cycles (typical) 4)Nominal 5~7 hour full charge time at 120~200mA current level 5)Built-in current limiter prevents overcharging 6)Can be charged using a traditional Ni-MH AA battery charger includes an LED indicator for charging