Solar powered Power Bank is made from old laptop battery. This is very cheap and, it can be charged from solar.
This also has a display which indicates power percentage in the power bank.

Let's get started

Step 1: Components

1.old laptop battery
2.18650 charging module
3.mini switch
4.6v solar panel
5.soldering
6.Gluegun
7.foam board
8.paint
9.wires

Step 2: Making

Remove the batteries from old laptop battery

In laptop the battery are connected in series remove those connections and connect all battery in parallel
So that our power bank capacity will increase.

Connect the two end of battery to 18650 module
Soldering wires in solar panel and switch

In 18650 module solder two wires at input terminal and connect one wire to solar panel another to switch.

Connect solar panel and switch.

Now if you place the panel in sunlight and make the switch on it will charge our power bank.

Now use the foam board to cut the shape and design you want.

If you have 3d printer then u can easily build the box for power bank

I don't have 3d printer so I bought this foam board and I am making the outer box with that.

That's it our power bank is ready.

Solar power power bank 30000 to 40000 mah