Solar powered 12 volt battery chargers are small solar panels that trickle charge your car’s battery while the sun is shining.
Basically, the solar charger provides a small amount of power to the battery, so that if you leave your car’s door open you won’t be left with a dead battery.
This reminds me: I’ve always wondered why cars don’t incorporate a small switch to turn off interior lights and headlights if they’ve been on for say a hour or two.
The best 12V solar charger I’ve found is the Sunforce 50012 1.8 Watt Solar Battery Maintainer. You can plug this 1.8-watt solar charger into your vehicle’s 12-volt lighter socket and position the panel to pick up the most daylight possible. Or, if you prefer, use the alligator clips to connect it directly to the battery, so you can keep your lighter socket open for cell phone chargers or other accessories.
The Sunforce solar car charger is available from Amazon for $34.95.