national park

Powerful Solar Power Solution for your Small Travel Trailer

After a year of trips with our Scamp 13’ (33 nights, 23 locations, 7 trips), we’ve gained a good understanding of how the trailer functions and which accessories provide added benefit.  Because our adventures often involve locations without electricity (such as some State and National parks and boondocking campsites), one excellent solution we implemented is a solar panel system.  The system ensures that our small travel trailer has the power needed to run the most essential functions (e.g. indoor LED lights, water pumps, heater, fans, and perhaps an electric tongue jack).  Most small travel trailers are powered by an on-board 12 Volt DC battery when off-grid or 110V AC onshore power when hooked up to a campsite’s electrical outlet (which is then converted to 12V DC).

The trailer’s battery is usually around 12.7 volts when fully charged and a good rule to ensure long battery life is to keep the trailer’s battery charge level above 12 volts (about 50% of its capacity).  A battery voltage meter should always be used to monitor the trailer’s battery voltage throughout each trip (we had Scamp install a SeeLevel II system when our 2020 Scamp 13’ was being built and Scamp now installs voltage monitors on its 2021 models).  There are aftermarket voltage monitors that simply plug into the 12 volt DC port in the trailer.  Here’s one with a BLUE display and here’s one with a RED display.

We’ve found that a basic 100W solar briefcase (two 50W solar panels which fold up on each other into a briefcase when not in use) is all that is necessary to provide enough power for essential systems in our Scamp 13’ (as long as the camper has sun exposure every few days).  The solar briefcase is nice because it is relatively light and can fit in the back of the tow vehicle when not in use.  We use an auxiliary battery power bank, a Jackery 500, for charging our phones, cameras, drone, and television when boondocking to reserve all of our Scamp’s 12V battery power for essential devices/functions.

The items needed to create a reliable solar system for your small travel trailer are:

1. High quality 100W solar briefcase (monocrystalline)
2. 2 pin waterproof male/female connector for the plastic battery box (houses the trailer battery)
3. 20 foot solar extension cables
4. 50 foot solar extension cables
5. Solar crimper tool
6. 12AWG (thickness) Wire (about 12 inches black / 12 inches red)
7. Solar panel cable connectors
8. Solar panel connector assembly tool
9. Multi-meter Tester
10. Portable Power Station

Update Sept. 2022:  after a few years, the bag that came with our solar panels split apart (it was always too small and difficult to deal with).  Here’s a much better bag!  Also, we’ve found having 50 foot cables which can extend the 20 foot cables to be a great option when the campsite is in shade most of the time and the longer cables can get the solar panels out into the sun!

Monocrystalline solar panels have the highest efficiency rates (more power per square foot) and perform best in low light conditions, so that’s the type we chose and we’ve been very pleased with the performance.  Make sure you choose a solar panel briefcase which comes with a charge controller.  The charge controller will keep your small travel trailer’s battery from overcharging.  On a recent trip to Joshua Tree National Park, we were down to 12.3 volts one morning.  As soon as the solar panels were plugged into the battery, the power registered 13.6 volts and maintained that steady voltage through most of the day.  When the solar panels were unplugged at sunset, the Scamp battery registered 12.7 volts (100% charge)!  We were staying at a Boondockers Welcome location without any hookups and relied on our Jackery 500 to charge our phones and other non-essential devices (including watching TV at night).  So, as long as there is sun every few days, the solar panel setup will keep the small travel trailer battery charged almost indefinitely!

Once you have the items needed to create your solar system, you will need to connect everything together.  Solar panel briefcases which come with charge controllers usually have a couple of metal clips on the end of each cable (black and red) which attach the solar panel cables directly to the small travel trailer battery (similar to the clips on car jumper cables, by clipping on to the red and black terminals of the battery).  Sometimes these clips are attached directly to the cables coming out of the solar controller and in other cases are separate and have connectors that plug into cable connectors coming out of the charge controller.  In any case, it is cumbersome to use the clips if your small travel battery is covered by a plastic housing box (like with our Scamp 13’).  We would have to take our plastic battery housing on and off each time we used the solar panels if we used the clips.  So, to make things easy, use a waterproof 2 pin male female connector port on the case.  Before installing onto the plastic battery case cover, some black and red 12AWG wires need to be soldered onto the inside port half, and ring terminals crimped onto the ends of the wires so they can connect to the trailer battery (Ring Terminal 12-10 Crimp Connectors, 5/16” Home Depot).  (If you are not familiar with soldering, either have a friend do it or hire an expert.  Otherwise, skip this step and just use the clips directly onto your battery terminals and omit the battery port.)  Once the inside port half has its cables, drill an appropriately sized hold in the plastic battery case cover and mount the port (the outside piece of the port screws into the inside piece to hold it in position on the case).  Then, screw down the ring terminals to the red and black battery terminals and close the battery housing box.  The last step is to solder the outside male connector (which plugs into the battery port) to the 20’ solar extension cables.

Depending on how the solar briefcase is configured, it might be beneficial to create two short cables (red/black) with the 12AWG wire and add MC4 connectors at the end which the 20’ solar extension cables can plug into (they should already have MC4 connectors on them, sometimes male on Black and female on Red).  Some solar briefcases are already configured with these short cables and connectors and it’s important to understand which connectors are male and which are female so they plug in appropriately.  Having short cables connected to the charge controller will allow the solar briefcase to be folded with the short cables still attached to the charge controller.  With this setup, all one needs to do when arriving at the campsite is open and position the solar panels, lay out the solar extension cable, and then join the connectors at the solar panels and plug the other end of the solar extension cable into the small travel trailer’s battery port.

It may be helpful to have a digital multimeter to check there is continuity from one end of the extension cables to the other and also to verify power is coming out of the extension cable at the male side of the port.  On my first attempt, no power was coming out of my extension cable.  So, I tested the continuity of the cable using the meter (makes a tone when the connection is continuous).  I found that one of the factory installed connectors wasn’t making a good connection and, after I reinstalled the connector, everything worked great!  You can also tell right away if your system is working just by checking your voltage.  If everything is good, the sun is out, and the panels are plugged into the system, the voltage will go up to the 13 voltage range right away (almost like the trailer is plugged into an electrical outlet).

Once you discover solar and how effective it is, you will never want to leave home without it!

Disclaimer:  You will get the same great Amazon price by clicking on the links here compared to buying directly on Amazon, but by buying here you will also be supporting the continuation of this website as we get a small commission from each sale.  These are products and procedures we use for our own Scamp that we selected and developed from our own research and experiences.  However, we do not endorse any specific product and cannot guarantee that the products we use are exemplary and the procedures we use are complete, accurate, detail the correct recommended procedures, or apply to your model small travel trailer.  It’s always best to double check with your manufacturer or operation manuals to ensure you are doing everything correctly.