Building your own solar powered phone charger from scrap electronics is a great way to reduce e-waste while harnessing the power of the sun. With just a few basic components, I was able to construct a simple yet effective solar phone charger that can charge my smartphone when I'm off the grid.
Gather the Necessary Materials
The core components needed to build a solar phone charger are:
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Solar panel - This converts sunlight into electricity. I was able to salvage a small 5V 100mA solar panel from an old solar powered garden light.
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Battery - To store the energy from the solar panel. I reused a rechargeable lithium ion battery from an old laptop battery pack. Make sure the battery matches the voltage of your solar panel.
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Charge controller - This regulates the charging from the solar panel to prevent overcharging the battery. I extracted a charge controller circuit from a broken solar patio light.
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USB charge module - Converts the battery power into a 5V USB output to charge your phone. I desoldered this from a retro wireless phone charger dock I found at a thrift store.
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Wires - For connecting the components together. I used recycled jumper wires from an old breadboard kit.
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Box/enclosure - To mount all the components together. I used a small plastic food container.
Having a soldering iron, wire cutters, voltmeter, and basic soldering skills will be needed for assembly.
Assemble the Circuit
With all my materials gathered, it was time to assemble the solar phone charger. Here are the steps I took:
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Attach the solar panel to the lid of the plastic box using hot glue. This allows it to sit vertically facing upwards when the lid is propped open.
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Solder the positive and negative wires from the solar panel to the charge controller board's solar panel input terminals.
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Solder the battery's positive and negative wires to the charge controller's battery output terminals.
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Solder additional wires from the positive and negative battery wire connections to the input terminals on the USB charge module.
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Mount the battery and charge controller board securely within the plastic box using Velcro strips.
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Attach the USB charge module to the side or front of the plastic box so the USB port is accessible.
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Securely close up the plastic box, while allowing the solar panel lid to open for sun exposure.
Testing and Usage Tips
With the solar phone charger wired up, it was time for testing.
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I verified the voltage from the solar panel with a voltmeter first. In direct sunlight, it read around 5.1V which was expected.
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I then measured the battery voltage. The lithium ion battery read 3.7V - a full charge. This meant the charge controller was functioning properly.
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Lastly, I confirmed the USB output read 5V by plugging in my smartphone. Within minutes, charging had commenced!
Here are some tips for optimal solar charging:
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Try to place the solar panel in direct sunlight as much as possible. Even cloudy days will generate some charge.
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Angle the solar panel so it faces the sun's rays directly as the sun moves across the sky. Adjusting it periodically helps maximize energy capture.
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Avoid shading the panel with obstructions like trees or buildings when possible.
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Check on the battery voltage occasionally with a voltmeter. When it drops below 3.7V, the battery will require recharging.
With scrap parts on hand, I was able to construct a custom solar phone charger that provides eco-friendly charging power whenever I need it off the grid. Getting creative with recycled electronics opens up possibilities for reducing waste while harnessing renewable solar energy.