Important reminder : The whole charging protection board has a protection function, if your battery protection board, before use, please remove the battery protection board, otherwise it may cause the trial is not normal. Module performance: The input voltage: 4.35-6 v (recommended voltage 5 v). Charge cut-off voltage: 4.2 V + / - 1% . Maximum charging current output: 1000 ma . The battery overcharge protection voltage: 4.28 V. Battery overcharge lifting voltage: 4.00 V. The battery discharge protection voltage: 3.0 V . Battery discharge termination voltage: 3.2 V. Battery: over-current protection current 3 a . The board size: about 2.5 * 1.65 CM. Light state: no load the light not bright, red light for recharging, is full of green light.