This is an easy solar flashlight that I made out of scrap parts, that I had lying around. I pulled the solar panel out of a dead solar power bank, and the battery/charger is an old wireless Internet hotspot. For the battery/charger you can use what I used, an old cellphone, an e-cig, any small Li-ion device, or even a Li-poly battery and a tp4056. It would definitely be a more useful use of an e-cig than smoking with it.

Supplies

Materials

6v solar panel
Li-ion battery and charger ( I used an old wireless hotspot )
4 white LEDs
10 ohm resistor
5v zener Diode
switch
wires
a small piece of clear plastic
a large piece of black plastic 11mm by 11mm (I used a part off of a laptop)

Tools

soldering iron
solder
wire cutters
wire strippers
box cutter
hot glue gun and hot glue
two part epoxy
multi meter

Step 1: Cutting the Pieces

Take your large sheet of plastic and cut you pieces as shown in the first picture. You will need to cut out a spot for the switch in one of the sides. Next take your clear piece of plastic and cut it into a rectangle that is 6.4mm by 1.2mm, or the same size as the smallest piece in picture one. The size of the pieces will differ depending on what parts you use.

Step 2: Wiring and Assembling

The wiring is relatively simple. Open up your hotspot/cellphone/other gadget and solder wires onto the battery's negative and positive pins. Next you have to figure out where to solder wires on for the 5v input. An easy way to do this is to plug your device in and use your multi meter and probe around until you get 5v. Then solder you wires on. If this seems a bit intimidating you could just use a micro USB plug to plug into your device's charging port instead. Close your device back up. Follow the wiring diagram to wire everything up.

Now take all the pieces and glue them together. It is pretty simple, especially if you tack all the pieces together with hot glue first. I used two part epoxy to glue it together. You could use hot glue but it would not be as sturdy.