Playing cards and renewable energy don’t seem to have much in common. However, a DIYer has posted details about how you can use your playing card to make a charger for AA and AAA rechargeable batteries that might be gathering dust in your desk drawer. The highly affordable and easy conversion process takes just 15 minutes of your time and a couple of solettes (small pieces of laser cut solar panels).
The materials required for the simple DIY process include a few solettes, adhesive copper tapes, super glue, four small magnets and playing cards. The process starts by folding the card in a way that the AA or AAA battery can fit snugly inside the folded shape, after which the copper tape is pasted on both ends of the card, which serve as the connection between the solar panel and the battery.
After the shape is ready, solar panels are attached in a series connection, which combines the output of the device to about 1.5 volts – enough to charge your battery. Magnets are then attached at both ends of the playing card so that the battery can be held in place while recharging under sunlight. While this ends the basic DIY process, you can also add a LED light to serve as an indicator that the charger is actually working and a schottky diode can also be added to make sure that the battery doesn’t discharge into the solar panel at night. Head over to Instructables for the complete DIY process or check out the video description below.