How to Build a Solar 12 Volt Battery Charger

by David Sandoval

Twelve-volt batteries (such as automotive or marine batteries) require periodic recharging. One way to recharge a battery is by using a small solar panel.

A solar panel converts light into electrical energy. Electrical current from a solar panel flows in a single direction -- from the solar panel to the battery -- even when the solar panel is isolated from light (such as on cloudy days).

Cut two pieces of wire, and strip one-half inch of insulation from the ends of each wire. Place the first ring terminal over one end of the first wire, and crimp the terminal to the wire. Place the second ring terminal over one end of the second wire, and crimp the terminal to the wire.

Attach the free end of the first wire to the positive terminal (which is marked with a "+" or "POS" indication) on the solar panel. Attach the free end of the second wire to the negative terminal (which is marked with a "-" or "NEG" indication) on the solar panel.

Place one of the screws through the hole on the first ring terminal, and through the hole on the positive battery terminal. Place one of the nuts on the end of this screw, and tighten the nut so that it holds the ring terminal snugly to the battery terminal.

Place the remaining screw through the hole on the second ring terminal, and through the hole on the negative battery terminal. Place the remaining nut on the end of this screw, and tighten the nut so that it holds the ring terminal snugly to the battery terminal.

Tip

  • check Check the battery once every half hour while charging. If the battery becomes hot to the touch at any time while charging, immediately disconnect the solar panel from the battery, and discontinue charging the battery.

Items you will need

About the Author

David Sandoval has served as a trainer and technical writer since 2000. He has written several articles online in the fields of home improvement, finance, electronics and science. Sandoval has an Associate of Applied Science in microelectronics from Northern New Mexico College.

Photo Credits

  • photo_camera solar cell research image by Albert Lozano from Fotolia.com