hello friends today I will show you how to make power bank under rs. 33 or $0.551 .I came this idea when I was thinking low cost power bank.

Step 1: Things We Need

for making power bank we need

1) battery holder for 3 battery - you can get this from old rc car or amazon

2) 3 AA 1.5V BATTERY -can get from any general stores or amazon.

3) micro USB cable - you can get this from USB data cable or old mobile charger.

4) mini switch - you can get this from electronic store or amazon (in large quantity)

So let's start to make mini power bank.

Step 2: Let's Make

First you have to take battery holder and insert 3 cells. and make the the marking of negative and positive current on battery holder.

now make circuit.

1) battery holder +to switch 1st.

2) switch 2nd to micro USB cable +

3) battery holder -to micro USB cable -

Note that black and yellow colour wire is negative

and green/red/white is positive.

After connecting as per circuit, connect micro USB to your mobile phone

And enjoy.