The button shows power volume as follows:LED 1:0%----25%
LED 2:25%----50%
LED 3:50%----75%
LED 4:75%----100%
Safety precautions:1.Do not throw battery into water or make it wet;
2.Keep the battery away from heat source(like fire or heater);
3.Do not throw the battery into fire or heat the battery;
4.Forbid to hammer to trample the battery;
5.Forbid disassembling the battery in anyway.
Packing list:1x External battery for iPhone 4/4S
1x USB sync date and charging cable
How to charge:Method 1:Connect the battery and computer USB port with USB 2.0 cable.
Method 2:Connect the battery and USB home/wall/AC/car chargerwith 2.0 cable.Then insert the charger into AC 110v-220v power outlet.
How to charge your iPhone:Step 1:slot in your iPhone
Step 2:switch on button of battery pack
Step 3:close the roof cover