Introduction
Building your own solar generator is an inexpensive way to get started with solar power. With just a few common household items and basic electronic components, you can make a simple solar generator capable of charging phones, batteries or other small devices. In this guide, I'll walk you through each step of the process to build a tiny solar generator from scratch using only about $5 worth of scrap parts.
What You Will Need
To build the solar generator, you will need the following materials:
Solar Panel
- Small 0.5W to 3W solar panel (can salvage from a solar yard light or garden light)
Battery
- One rechargeable AA or AAA battery
Wiring and Electronics
- Jumper wires
- Diode (1N4007 or similar)
- USB charging module/board
Box (optional)
- Small plastic food container or project box
Tools
- Wire cutters
- Wire strippers
- Soldering iron and solder
- Hot glue gun
Total Cost: Around $5
Most of these parts can be salvaged from old devices or purchased very cheaply. The solar panel is the most expensive component but small 0.5W to 3W panels can be found for $2 to $5.
Step 1: Prepare the Solar Panel
To start, take apart a small solar powered yard light or garden light to salvage the solar panel. Carefully open up the plastic housing and desolder the solar panel from the circuit board inside.
Be sure not to damage the metal tabs on the back of the solar panel that will be used for connections later. Also, set aside any batteries or circuits from inside the light - we may be able to reuse some of these components.
Step 2: Wire Up the Battery and Diode
Next, we need to connect the rechargeable battery to a diode to prevent discharge at night.
- Strip about 1/2 inch of insulation from the ends of two jumper wires.
- Connect one end of the diode to the positive terminal of the battery using a jumper wire.
- Connect the other end of the diode to the negative terminal of the battery using the other jumper wire.
The diode should only allow current to flow in one direction - from the solar panel to charge the battery - preventing the battery from discharging back through the panel at night.
Step 3: Connect the Solar Panel
Now we can wire up the solar panel to our battery circuit.
- Cut two more jumper wires and strip off 1/2 inch of insulation from both ends.
- Attach one wire from the positive tab of the solar panel to the positive end of the diode.
- Attach the other wire from the negative tab of the solar panel to the negative terminal of the battery.
This will allow power generated from the solar panel to charge the battery through the diode.
Step 4: Add a USB Charger (Optional)
To make our solar generator more useful, we can add a USB charging module. This will allow us to charge phones, tablets or other USB devices.
- Solder the input terminals of a small USB charging board to the battery's positive and negative terminals.
- Attach a USB cable to the output port of the charging board.
Now we will be able to charge USB devices directly from the power stored in the battery.
Step 5: Enclose in a Case (Optional)
For a more finished look, you can mount all of the components inside a plastic food container or project enclosure.
- Drill holes for wiring to pass through and mount the solar panel on top.
- Use hot glue to hold the components in place securely.
The case helps protect the electronics and makes the solar generator fully portable.
Usage Tips
That's it! To use your new solar generator:
- Place the solar panel in direct sunlight to charge the battery during the day.
- Connect phones, batteries or other USB devices to the USB port to draw power as needed.
- Bring it indoors or cover the panel at night to prevent discharge.
Some usage tips:
- Rechargeable NiMH batteries work well for higher capacity.
- Maximum power output depends on the panel size - 0.5W to 3W is ideal.
- Add a charge controller for optimal charging and device protection.
And that's all there is to it! With just a few dollars worth of basic parts, you can build your own portable solar power source.