We spent 28 hours on research, videography, and editing, to review the top options for this wiki. The electrical charge in 12-volt batteries slowly depletes over time, so if you have a car, ATV, boat or RV that sits unused for weeks at a time, you’ll want one of these solar chargers to keep the battery topped off. These gadgets can help extend the life of your battery, and some even include a controller to prevent harmful overcharging. When users buy our independently chosen editorial picks, we may earn commissions to support our work.
8. TCXW 30-watt
Resistant to breaking because it’s bendable, the TCXW 30-watt is made of durable PET and polycrystalline solar cells, and it works even on cloudy days. It features a reverse blocking diode that prevents discharge at night, and it is lightweight and easy to move.
- Alligator clamps included
- Suitable for any 12-volt battery
- Too tall at 20 inches for some uses
|Rating||4.2 / 5.0|
7. Suaoki 18-watt panel
The cells of the Suaoki 18-watt panel boast a 22-percent efficiency, better than many other products on the market. This one conveniently allows you to charge your battery via the cigarette lighter socket rather than having to open the hood and clamp to the battery.
- Weighs less than one pound
- Water- and heat-resistant
- Requires direct sunlight
|Rating||3.6 / 5.0|
6. Mighty Max 10 Watt
Designed to maintain any 12-volt battery, the waterproof Mighty Max 10 Watt comes with everything you need to easily harness the power of the sun. The alligator clamps are pre-attached, and it has pre-drilled holes on the frame for easy mounting.
- 6-foot long cable on the clamps
- Compact design fits almost anywhere
- Charging controller not included
|Brand||Mighty Max Battery|
|Rating||3.9 / 5.0|
5. Sunway Multi-Function
Want to maintain your car, truck, or RV battery and charge your phone or other electronic device? You can do both with the Sunway Multi-Function, which has a USB port in the housing and lets you stay juiced up wherever the sun shines.
- 6 watts of output
- Versatile 8-foot cable
- Cannot withstand exposure to rain
|Model||6W solar panel charger|
|Rating||3.8 / 5.0|
4. Powereco Solar Panel
Available in 10, 20, and 30-watt models, the Powereco Solar Panel is waterproof and equipped with a sturdy anodized aluminum frame and anti-reflective glass for maximum efficiency. Be aware, though, that you’ll need to buy a separate controller to prevent overcharging.
- Weighs just two-and-a-half pounds
- Easy to set up and use
- No reverse diode to stop power drain
|Rating||4.1 / 5.0|
3. Sunway Solar Portable
At just 14 inches long and 5 wide, the Sunway Solar Portable is a compact model that you can tuck neatly on your dashboard or attach to the windshield with suction cups. Adding to the convenience, it lets you maintain your battery through the cigarette lighter socket.
- Durable plastic housing
- Blinking led indicates charge status
- Covered with ultra-clear pv glass
|Model||3W solar trickle charge|
|Rating||4.9 / 5.0|
2. Eco-Worthy 20-Watt Polycrystalline
The Eco-Worthy 20-Watt Polycrystalline is a sturdy option with a controller that protects against overcharging and unintentional discharge. The manufacturer is so confident in the quality of this product that it comes with a 25-year power output warranty.
- Also has a 5-year materials warranty
- Includes 2-meter extension cable
- Corrosion-resistant aluminum frame
|Rating||4.6 / 5.0|
1. Battery Tender
The Battery Tender is a great choice for keeping any 12-volt battery conditioned. It features a built-in microcontroller that prevents overcharging, and reverse-polarity protection so that it does not drain power when your battery is fully charged.
- Five watts of output
- Waterproof for inclement weather use
- Built-in temperature sensor
|Rating||4.9 / 5.0|