Dometic CFX5 Refrigerator Tow Vehicle Installation with Solar Power

**jd1923** · August 17

After deciding on which model to buy, what size would fit, and whether to go single or dual zone we went with the newest Dometic model CFX5. The single-zone 45L model fit perfectly in the front curbside area of the truck, behind the toolbox and in front of the wheel in arms reach from the passenger side truck door, so convenient holding cold water and food while towing!

I built a stand to fit the cooler above the corner of the wheel well and bring the control panel to the proper height, just above the truck rail. Notice one stand support is cut short to clear the wheel well. There are four 6mm threaded sleeves built into the bottom of the fridge to hold it down. I let the refrigerator sit for 48 hours after having it sideways when mounting the platform. It looks very good installed, doesn’t it?

**jd1923** · August 17

We took a 5-day trip and we absolutely loved having the extra cooled water and fridge space. On our way back home we stopped at a butcher, removed the drinking water from the fridge and set the thermostat down to freezer temps. It kept our steaks, chops and hamburger meats nicely frozen on the way home.

On our first trip, I had 12VDC from the truck batteries wired to the fridge to run while driving. When camped we merely plugged in the fridge using a 110V extension cord plugged into the Oliver. The 110V connection will override the 12VDC, so you can have both wired to the CFX5 (not true in earlier models).

Edited August 18 by jd1923

**jd1923** · August 17

I came up with the idea to add a 100W Renogy flexible solar panel and a small Victron MPPT 75/15 SC. My goal was the solar energy should be enough to replenish the truck starter batteries while running the CFX5 refrigerator and our Pepwave router system. I had already upgraded the TV with a HO alternator and AGM batteries. The solar addition should keep my TV starter batteries fully charged, except in the mornings after running the router and fridge without sun overnight. After a few hours of late morning sun fully charged again.

I have a spot in the bed where I could mount a second solar panel if needed. Those of you who have a truck cap should mount 2-3 of these 43x23” Renogy flexible panels in a heartbeat! I will share links for components used in a later post.

I got the installation done Friday. I deleted the solar wire terminals and used butt crimp connecters and heat shrink adding a few feet of flexible 10/2 wire (left cable in the picture). The black wire pair is coming up through the bottom of the toolbox from the cooler. The short wire on the right exits the toolbox and goes stgright down to the frame where I intercepted the 4AWG wire from my DC2DC charger installation adding a simple single bolt buss for lowest possible resistance.

Yesterday I thought I should trim the panel narrower. The Renogy panel is 23” wide and the standard truck toolbox is 21”. The job would have been easier if I had trimmed it before mounting it, but it came out very nice with a little extra effort. I used a boxcutter and a 1 1/4" bracket clamped to the edge of the panel and trimmed that amount off both sides, filing the edges smoothly afterwards. VHB tape was used to mount the solar panel to the toolbox lid and to mount the solar controller inside the box.

I also purchased an inexpensive waterproof grill cover to protect the Dometic CFX5 cooler. They make an insulated cover for about $150 but I wanted more airflow than insulation and wanted a cover that would easily come off and on. I have a 1” piece of Styrofoam inside the cover to insulate the top from direct sun.

Edited August 18 by jd1923

**jd1923** · August 17

I’m really happy with the results! The 100W panel is regularly getting 70W, during the day, sitting flat, not angled to the sun. When getting high of 75W it handles the 5.6A required by the CFX5 with compressor running (observed 0A with compressor OFF, 3.7A lowest reading with compressor running and 5.6A highest reading), plus another +0.4A charging the TV starter batteries. This adds to 6A provided by solar. The Pepwave router was also running behind the scenes and it draws +/- 1A.

This particular Victron SC has a terminal for 3 pairs of wires (see graphic). One pair for the battery (BATT), Solar Panel input (PV) and LOAD an output circuit. I thought this is a handy extra. I could have wired the CFX5 cooler to battery, but this LOAD circuit allows for special monitoring (the Pepwave is wired directly to the batteries).

Edited August 17 by jd1923

**jd1923** · August 17

We will have a real test on a 3-week trip to SW CO Sept-Oct. Soon, I will determine whether a 2^nd solar panel will be necessary. The 75/15 solar controller can certainly handle 200W total.

Yesterday at 4PM I pulled the truck back into our garage, so no more solar power. The truck starter batteries were at 12.54V at the time. The CFX5 was set at 25F with a few water bottles in it. At midnight, I set the thermostat up to 36F. Now after running for 20 hours without solar power, the start batteries voltage is 12.11V (-0.43V loss in 20 hours). I’m certain my truck will start fine today at this voltage.

Edited August 18 by jd1923