Power Bank DIY Boost Module Control Board available batteries: 18650 battery, cell phone battery, flat battery, MP3 battery 3.7V-4.2V polymer lithium battery, single (chip) power supply, but also multi-section (chip) parallel power supply (does not support the series, ). (Note: parallel increase in capacity, series is to increase the voltage, can only be used in parallel!
Can be connected in parallel 2-6 string 18650 battery.
Not available Battery: Dry batteries, accumulator battery, 1.2V rechargeable batteries, nickel-metal hydride batteries.
Built-in lithium battery protection IC, over-current, overvoltage, undervoltage protection;
The positive of the battery connected to B +, and the negative connected to B-. If the reverse will damage the control board.
Product Features: 
1.4 level LED lights show power, non-working state intelligent automatic shutdown;
2. Built-in lithium battery protection IC, over-current, overvoltage, undervoltage protection;
3. Dual USB output;
4. Board size: 69 * 32 * 8mm (L * W * H).

Product basic parameters:
Input port: MicroUSB
Input requirements: 5V constant voltage power supply can be done charging input power supply, the most matching charger for 5V1A or more
Output port: USB
Output parameters: 5V1A / 5V2A adaptive

Please note the following points when connecting:
1, The battery should be connected in parallel, the voltage to work between 3.2-4.2V, 18650 batteries and polymer batteries can be;
2, The positive of the battery connected to B +, and the negative connected to B-. If the reverse will damage the control board.
3, Old and new batteries, model brand inconsistent battery can not be mixed.