All 3.7V-4.2V rechargeable lithium batteries, such as cell phone batteries, flat batteries, 18650 batteries and so on.It could be connected to a lithium battery can also be connected in multiple sections of lithium batteries Lithium positive pole connected B + Lithium negative then B- 3 USB output, according to the device automatically recognize the output 5V1A or 2A current on the phone. Flat charge, you can also charge three mobile phone at the same time.