We used our Coleman 40 qt thermo-electric cooler for the first year and part of the second season. Initially we powered it off the vehicle 12v system only while driving, relying on ice packs when parked. On really hot days, or for traveling to hotter locales, this would not be sufficient to keep food cold, but normally it worked just fine with ice bottles over a long weekend in the mountains.
Once we installed the solar panel and battery array we found that we had sufficient power, even on more cloudy days, to charge the house batteries and run the cooler. The limits of a cooler are in its constant power draw and in its cooling relative to ambient temperature. At 5 amps constant draw it should in theory be able to stay plugged in 24/7 and not kill the 260ah battery array (5amps x 24hrs = 120ah). We found that after running for a bit the cooler only drew about 4amps. The cooler fan is noisy so we did not run it at night.
I conducted a bit of research into RV refrigerators and found that while the 3-way units (propane/12v/120v) were popular for off-grid excursions, they worked off absorption and were somewhat fussy about being level. We did not want to install propane as we already had a naphtha stove and did not want a second fuel source to worry about. In addition there would be the question of where do you put the propane bottles given our van was never setup for this. Most RV forums said you could not run 3-way units reliably off 12v power. The final concern was how much off level was acceptable without damaging the unit? We were not going to purchase leveling equipment just for a fridge.
There are however compressor-style fridges available that can operate constantly at 30 degrees from level without issue. After a sufficient amount of research into the technology and options I found one that fit the space we had for our kitchen and averaged about 2.5 amps – 1/2 the amps of our cooler: the Nova Kool r2600 2.4 cubic foot/63 liter fridge/freezer. I created a rough-in for this unit and we continued to use our cooler believing it would get us by for the season.
When we were planning our first longer trip we realized that the ice in cooler wasn’t going to cut it for food keeping as the ice held out only for a long weekend. It wouldn’t do to be dependent on ice as to when and how long one stopped. We shopped around and bought the Nova Kool unit out of Binnacle in Halifax as it was a substantial cost savings over the ones I could find locally in Edmonton even when I factored in expedited shipping. This gave us an additional 20 litres of cold food storage and 3 litres of freezer space.
Initial testing of the fridge was to leave it running in the parked boogie van after installation. The batteries were in good shape in the morning over several days testing, being at or above 13v when the sun came up. We will need to ensure we have some airflow in the van during the day to keep the interior as cool as possible, however, the solar array will produce all the power required to run both the refrigerator and charge the house batteries entirely. Below is the unit in our updated kitchen.
I installed a separate 12v power port inside the electrical box so the unit can be plugged in constantly. I plugged in the 120v power cord to our shore power power bar as it will prefer this if available.
We upgraded our fridge with a plastic veggie tray from a home outfitting store which makes it all the more fridge-like.
On our first longer trip (11 days) the fridge got a real test. It rained regularly, there were some dark sky days, and some of the camp sites we stayed at were relatively dark with little morning or evening access to sunlight. Even with the fridge constantly plugged in our little solar/battery array was never below 12.7v in the morning. We did not find the unit to be noisy at night, nor was ventilation a concern with our open design. We crammed the fridge and freezer prior to departure and were able to enjoy the ability to keep food like home whilst on the road, including ice for drinks. The tray made it easy to bring out the veggies in one fell swoop, thus shortening door opening time, which in turn kept the freezer from icing up too much.
If your setup allows for some sort of 12v power array we would highly recommend looking into a compatible compressor refrigerator/freezer to extend your range and food storage capability. There is not comparison with any form of icebox for longer trips.