Specification Product name Upgrade Version USB Li ion Battery Charging Module BoardInput voltage 5VMaximum charging current 1000 mACharge cut off voltage 4 2 V 1 Battery overcharge protection voltage 2 5 VBattery over current protection current 3 AInput interface Micro USBDimension 2 6 x 1 7 cmQuantity 5pcsFeatures Input port with micro USB female can directly use mobile charger for input to the lithium battery and still retain the input voltage wiring solder joints can be very convenient Connect the battery to B B insertmobile phone charger to the USB Female then red light is charging and green is fully charged Package included 5 x Upgrade Version USB Li ion Battery Charging Module Board