Input with a MICRO USB home, you can directly use the phone charger to do input to the lithium battery charging, And still retains the input voltage wiring pads, can be very convenient DIY Input voltage: 5V Charging cut-off voltage: 4.2V ± 1% Maximum charge current: 1000mA Board size: 2.6 * 1.7CM Battery over discharge protection voltage: 2.5V Battery overcurrent protection current: 3A