How to find the best solar panel kit for your RV camper

How do I select the parts for my solar power system that will fit your caravan camper? Here are a few suggestions.

To run the lights only

This is a very small setup that is suitable for not much more than running the LED lighting in your camper. However, it's a cheap setup and easy to get started with. But be aware that you will probably have to change all the equipment if it turns out to be too weak.

Components	1 x 20W, 12V solar panel 5A PWM controller 18Ah battery (lead-acid) / 216Wh / 100 usable watt-hours**
Charging time	About 6 hours from 50%* in optimal conditions
Price	Approximately $100
Suitable for	Simple LED lighting, at 20W, about 5 hours usage

To top the batteries if off-grid once in a while

It's the same as the previous setup, except that the battery is larger. The battery charge will be slow, but if you only use it for some lighting, water pumps, and some smartphone charging once in a while, you should be fine. If the camper is being unused for a couple of days (at least in the summer), the solar panel should be able to make sure the battery is always fully charged.

Components	1 x 20W, 12V solar panel 5A PWM controller 80 Ah battery (lead-acid) / 960Wh / 450 usable watt-hours**
Charging time	About 25 hours from 50%* in optimal conditions
Price	Approximately $150
Suitable for	LED lighting, at 20W, about 22 hours usage Water pumps, at 35W, about 12 hours usage Smartphone charging, at 5W, about 90 hours

All-around off-grid kit

The price per watt on solar panels (PV) is dropping each year, and purchasing a 200W module today cost less than what you had to pay for a 100W module just a few years ago. Also, the capacity per size unit has increased, making it possible to get more power from your RV rooftop than before.

In this setup, we have increased the solar panel so that the battery will charge faster. This enables more continuous usage, and you can allow yourself to add an inverter to run more power consuming appliances as well. We have also exchanged the PWM controller with an MPPT controller, which is more efficient.

Components	1 x 200W, 12V solar panel 20A MPPT controller 80 Ah battery (lead-acid) / 960Wh / 450 usable watt-hours**
Charging time	About 2-3 hours from 50%* in optimal conditions
Price	Approximately $360
Suitable for	LED lighting, at 20W, continuous when the sun shines, and about 22 hours usage when dark Water pumps, at 35W, continuous when the sun shines, and about 12 hours usage when dark Smartphone charging, (may require an inverter) at 5W, continuous when the sun shines, and about 90 hours when dark Laptop charging, at 60W, continuous when the sun shines, and about 7,5 hours when dark
May work for	RV Fridge, at 180W, continuous under optimal conditions when the sun shines, about 2 hours when dark. However, there is a risk that the fridge can damage the battery if it doesn't cut the power source if the voltage is below 10.8V. Battery damage can probably be avoided by connecting the RV fridge to the solar charge controller load output instead of directly to the battery. But you should probably increase the AMP rating to at least 30A or 40A for the controller to avoid damaging it. Also, by running av RV fridge on this setup may use up all the electricity, so that you have nothing left for other appliances.

* A few words about lead-acid batteries

Although lead-acid batteries are less expensive to buy than Lithium-based batteries, they have a major drawback in that only up to 50% of the total capacity can be used. After 50% have been used, the voltage will drop to a point that is too low for most 12V appliances. Also, and more importantly, going below 50% (about 10.8V) could damage the battery and even make it unusable.

Building your own solar charging system? Use our calculator

Figuring out the best configuration can be challenging, and especially to figure out what the minimum specifications of your charge controller should be. Luckily, you can use our visual charge controller calculator, where you "build" a virtual solar panel setup, to get the minimum solar charge controller requirements right away.

Updated July 23, 2020