Looking for a solar charger for your phone, your laptop, or even for a back-up generator for your home. You can find products for all three of these needs, but expect to shell out: even smallest solar battery charger runs $30-40. A diy battery charger, on the other hand, can cost you as little as $4-5, and even make use materials you already have on hand.
After a visit to some prepper boards on Pinterest (it's not all weddings and wish lists over there), I discovered that homemade solar chargers are pretty popular with that crowd, and run the gamut from really cheap models that can power up small rechargeable batteries to full-scale generators that will cost you several hundred dollars to build. But if you've got a dead phone battery on a camping trip, or the power's out after a storm, you'll be glad to have one of these on hand.
