Intro: DIY Solar Charging USB W/ Battery
In this instructable, you will learn how to design and wire a circuit that will allow you to harness the power of the sun to charge your phone and to charge a battery for later use.
Step 1: Gather Your Tools
All tools and parts (as seen in picture) necessary to complete the project are listed here.
- 5V Solar Panel (mine is 130mm x 150mm)
- 5V Powerbank (mine is 1000mAh)(this will include the USB and Battery)
- Wire (stranded wire is best)
- Soldering Gun
- Wire Strippers
- Electrical Tape
- Heat Shrink
- Multi-Meter (optional but recommended for testing)
- Screwdriver (may be needed to take powerbank apart)
Step 2: Soldering the Solar Panel
Although solar panels vary in shape and size tremendously, most of them should have two circuit leads which are labeled with a plus(+) and minus(-) on the back side. Wire location is very important when connecting them later on so be sure to mark one or use different colors (I used black and black/white) for clarity. Solder one end of each wire to the plus and minus as seen in photo.
- Take two wires and strip the insulation on each end of it carefully with wire strippers about a quarter inch.
- If this is your first time soldering, be very careful on not using too much solder or burning the solar panel. A good tip is to gently hold the soldering gun on the wire and add some solder to the metal lead, then heat the solder up and place the wire into the metal until it is fully submerged.
Step 3: Disassembling the Powerbank
The Powerbank contains two very useful parts used in this design. It holds the USB (input/output with a switch) and the battery. Most are fairly easy to disassemble as they either slide out of the metal/plastic frame or are held in by hidden screws usually found behind graphic tape.
Once the Powerbank is taken apart it is now ready to be adapted into the circuitry.
Soldering the USB and battery are now the next thing on the list.
- Strip the ends of 4 wires this time.
- Take another piece of wire and solder it from the positive(+) marked metal lead on the USB.
- Solder a separate wire to the negative lead on the USB, leave both of these wires alone for now.
- Next solder another lone wire to the negative (usually flat and metal) end of the battery.
- Lastly solder a wire to the positive end of the battery (usually indented metal).
Step 4: Finish Soldering
It is now time to connect all the positive ends together as well as the negatives ends, this will complete the circuit. Make sure that you remember your heat shrink or it will need to be redone.
- Slide a strip of Heat Shrink (about 1 1/2 inches for insulation) onto each of the wires connected to the solar panel to be used later. (This step must be done now.)
- Place the Solar panel positive wire end towards the positive ends of the USB and Battery and solder them together (direction labeled in photo). Solder the 3 ends together and slide the heat shrink over it, with the soldering as centered as possible.
- Do the same with the 3 negative wires as well, then slide the heat shrink for the solar panel wire over the solder.
- Lastly use a hairdryer or some other warming device to finalize the heat shrink (be careful to not use/overdo soldering gun if you use it for this as this can melt the heat shrink).
Step 5: Testing Phase
Now that your circuit is complete, be sure to electrical tape any loose wires so that they do not break away or come apart from the rest of the design.
Be sure to test the wires and circuit with a multi-meter or connect a phone/device to make sure it works well.
Step 6: Building the Frame
A frame that holds this can be made out of anything. I have designed one in Autodesk Inventor to 3D Print and am waiting for it to print. You can design a frame yourself or print what I have already designed if you have access to a designing software and a 3D Printer. (See photo)