Solar power is big these days, from power plants to rooftop arrays! This guide shows how to build your very own solar charger for small electronics. Homemade solar panel pdf directions are designed to use parts from our Solar USB Charger 2. This project was designed for beginner Makers and students.
It requires a base knowledge of soldering. While you can charge small gadgets, this project is not appropriate for camping or to be relied on for survival situations. This section will be most useful for those sourcing their own parts, if you are building from a kit, feel free to skip ahead. USB charging requires 5V at around 500mA of power to charge most gadgets.
To avoid this tradeoff, we could use larger solar panels and larger batteries, but this would result in a larger, heavier, and more expensive charger. If you’re using an older Apple product, make sure your USB Charging Circuit is compatible. Typically a USB gadget requires just power from a USB port to charge. Phones will check the USB data ports in order to identify what kind of device it’s plugged into and change charging speeds if it thinks the port can support it. Unfortunately if it doesn’t see anything on the data tabs it will refuse to charge. Our USB Charging Circuit needs a minimum of 2V to operate, so we need to choose power sources with this in mind.
We always advise the use of power storage when doing a solar project. Solar is inconsistent due to the inconsistent nature of the sun. Using batteries helps stabilize the flow of power, and also lets us hold onto that energy for later use. In this project we use three rechargeable AA batteries.
2V of power and using three in series gives us 3. Using two batteries will cause our voltage to drop below 2V too quickly, and our USB Charging Circuit won’t be able to operate. Four batteries would require a much larger solar cell to charge. Batteries require a minimum voltage in order to charge, but raising the voltage will not cause the batteries to charge faster. The general rule is to provide 1. We want our solar panel to meet the minimum voltage, even on days with a few clouds, so a 6V panel does well. When charging AAs using a wall adaptor, we’re able to charge them at high speed due to smart chips that constantly monitor the battery.
Use a lighter, clean up by clipping off any bits of wire that stick out. But this would result in a larger, altoids tins and metal project boxes may look nice, you should have two wires attached with two loose ends when you are done. Our solar cell is rated for only 80mA, for both the iphone and google phone applications. If you did that – we’re able to charge them at high speed due to smart chips that constantly monitor the battery.
Our solar cell is rated for only 80mA, so we’re completely safe! Different panels and batteries vary, so make sure yours work well together. One good aspect of the trickle charge method is that it will never over-charge the batteries. Once they’re full they just stay topped off.
Above is a circuit diagram for this project. A diode has been put in place to prevent power from flowing the wrong direction into the solar cell. This is a very common design for solar chargers. 8-inch laser cut Baltic Birch plywood, with holes cut for wires, switches, and ports.