Hello Friends,

This is my new instructable about How to make a simple Mobile Power Bank. Every person who keeps mobile or smartphone required a Mobile Power Bank. Because till now mobile phone's battery power is less to power the mobile whole day or for few days.

DIY Video Link

About Power Bank Circuit:-

Last month I want to make an own power bank then I search power bank circuit. I found a circuit which has two 5v output ports (1A and 2A), one micro USB charging port and have one display. On the display, you can see that how much Power Bank Batteries are charged and also how much current you draw during recharging your mobile battery.

Step 1: Parts Required : -

Dual USB 5V 1A 2.1A Mobile Power Bank AliExpress buy
Mobile Batteries (7600mAh total power)
Plastic Box or any Encloser

I have 5 old mobile Batteries.

You can use Laptop Li-ion 18650 batteries instead using mobile batteries. Laptop batteries are more efficient and have more power.

Step 2: Prepare Encloser : -

Now time to enclose the Power Bank circuit and Batteries. First take enclose and mark outline on it as the circuit output ports are fit (shown in above pictures).

Step 3: Battery Connection : -

Take one mobile battery and check its polarity and mark on it. The Same process is applied to all other battery.

Then connect all battery in parallel as the schematic shows in above picture. At the last stage connect the Power Bank circuit. Make 100% sure your all connections right then connect the Power Bank circuit. Positive wire is connected to the positive terminal of Power Bank and the Negative wire is connected to negative terminal of Power Bank.

Step 4: Ready : -

Now your Power Bank is ready to use.

I hope you like this Instructables.

Step 5: Efficiency and Calculation:-

Yes, the efficiency of Mobile batteries is less as a Power Bank. You can replace mobile batteries to Laptop Li-ion batteries 18650. Laptop Batteries 18650 are more efficient and reliable. Now in the market, another type of Li-ion is available named TESLA 2170. Tesla Company made this battery for Electric Cars. This battery is perfect for more efficient Power Bank.

Calculation : -

Estimated Battery Life = Battery Capacity (mAh) / Device Consumption (mAh)

Convert mAh to Watt hours =(Battery Capacity(mAh) * Battery voltage) / 1000