What Size Fits the M1?
The M1 has no dedicated fridge bay, but the truck bed floor area is generous. 12V fridges from 35L to 65L have all been run successfully in M1 builds. The practical limit is less about width and more about how much floor space you want to dedicate to the fridge vs. gear storage.
Common sizes in the M1 community range from 35L (compact, solo use) to 63L (2-person or longer trips). The tradeoff: larger fridges draw more power and take more floor space. Most owners report 45–50L is the sweet spot for 2-person weekend trips, enough capacity without taking over the floor.
Power Draw & Battery Sizing
A 12V fridge is typically the largest single power draw in an M1 build. Unlike a fan or lights (which run intermittently), a fridge compressor cycles continuously, especially in warm weather.
Rough estimates for a 45–50L compressor fridge (e.g., Dometic CFX3 45). Real-world daily draw varies significantly with ambient temperature:
- 50°F ambient: approximately 12–18 Ah/day (compressor cycles rarely)
- 70°F ambient: approximately 20–25 Ah/day (typical spring/fall camping)
- 90°F ambient: approximately 30–40 Ah/day (summer desert or hot weather)
Add your fridge draw to your other loads (fan ~20 Ah/night, devices ~3 Ah) and you're looking at 50–65 Ah per day in typical summer camping. A 100Ah LiFePO4 (80Ah usable) barely covers one night without recharging. Most owners running a fridge upgrade to 200Ah battery and pair it with solar. See the battery guide and solar guide for sizing that accounts for fridge draw.
Placement in the M1
The M1 has no designated fridge location, which gives you flexibility but requires some planning. Common approaches from community builds:
- Floor at the foot of the bed, most common. Easy access, no hardware required, and the fridge can be grabbed in or out of the camper easily. Works well for most 45–50L sizes.
- 80/20 slide-out, a popular DIY mod. The T-track system makes it easy to build a fridge slide that pulls out through the rear hatch. Adds ~5–10 lbs but makes access much cleaner, especially when the sleeping platform is deployed.
- Truck cab while driving: some owners move the fridge to the back seat during drives to keep the bed clear for gear storage. A running truck's accessory outlet can power a 12V fridge, and many fridges come with a long enough DC cord.
Compressor vs. Thermoelectric
Use a compressor fridge, not a thermoelectric cooler. Why:
- Thermoelectric coolers only cool ~20°F below ambient. On a hot summer day at 95°F, that's 75°F, not cold enough to safely store food. They also draw constant high current regardless of temperature.
- Compressor fridges maintain a true set temperature (like a home fridge), cycle on/off efficiently, and work in any ambient temperature. They cost more upfront but are the right tool for the job.
Community Picks
Payload Considerations
A loaded fridge adds meaningful weight to your build. Don't forget to account for:
- Fridge unit weight (empty): typically 30–45 lbs depending on size and brand (45L 12V compressor units are 40+ lbs)
- Food and drinks: easy to forget this, a loaded fridge adds another 10–30 lbs
- Mount hardware or slide: additional 5–10 lbs for any mounting solution
Use the payload calculator to add your fridge + contents to your build and see the total margin.