Specification: Input Voltage: 5V Charge Cut-off Voltage: 4.2V ±1% Maximum Charging Current: 1000mA Battery Over-discharge Protection Voltage: 2.5V Battery Over-current Protection Current: 3A Size: 2.5*2cm / 1*0.8in Quantity: 10pcs Weight: 27g / 1oz (approx.) Current Adjustment RPROG (k) IBAT (mA) 30 50 20 70 10 130 5 250 4 300 3 400 2 580 1.66 690 1.5 780 1.33 900 1.2 1000 Package list: 10 * Charging Boards Note: 1. The ammeter used to test current can only be connected to 5V input of board in series. 2. The charging current is batter to be 0.37 times of the battery capacity, e.g. for a 1000mAH battery, the charging current should be 400. 3. The charging connection wires cannot be too thin nor too long, otherwise it will result in a big connection resistance. 4. Keep a good connection of contact with the battery. 5. If 5V input voltage is higher, 5.2V or 5.5V, for example, can cause lack of charging current less than 1000mA, this is normal.The high voltage will cause chip fever and it will automatically reduce the charging current, in order to protect chip from burning.Chip temperature reaching 60℃ is normal when it is working. 6. Reverse connection at output (battery) will burn out the chip, please be aware.