The Sunforce 50022 5-Watt Solar Battery Trickle Charger gives you another reason to love the sun - it will help keep your vehicle's battery charged anywhere anytime. Just plug this helpful 5-watt trickle 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 included battery clamps to connect it directly to the battery so you can keep your lighter socket open for cell phone chargers or other accessories. Regardless of how you hook up the battery charger you'll never get caught off guard without the juice you need to start your car. The amorphous solar panel is completely weatherproof charges in all daylight conditions and has an integrated blocking diode that protects against battery discharge at night. The 50022 is the ideal choice for automobiles recreational vehicles (RV) tractors boats electric fences telemetry and more. It has a maximum power output of 5 Watts and 350Mah. With a maximum temperature range of -40 to 176-degrees Fahrenheit this unit measures 14 x 0.75 x 13 inches (WxHxD) and weighs 4 pounds.