BMW i3 EV Micro Camper part 4, DIY Efficient Fridge Design

[@samaraericaaa]

I'm interested in seeing you take this thing camping for real!

[@OlinLagon]

Excellent series. Thanks

[@bucabrandon]

Great stuff. Would like to see all this put to the test on a weekend getaway.

[@tawensan7162]

Great info... May do it for next summer.

[@coolfrost6]

I'm pretty sure that if you could find a compressor fridge with the same internal volume i would be minimum 2x the efficiency. I think the the wattage numbers you are finding is the peak consumption when it is cooled down it should only cycle on oncasionaly. But i don't think that there is a compressor fridge on the market that is small enough for the space behind the driver seat, so for this application the TEC fridge is probably the wise choice.

[@connermoyer2353]

Regardless, the fridge will 'die' after the ~30min climate control (and i3) turns off. I'd rather have the compressor fridge running in the trunk off the 12V until bedtime, then put it in the front seats for 'overnight mode'. Added bonus is you don't have to go far (assuming you've already broken down bedding and moved fridge back to trunk) to grab your creamer for that coffee shelf in the trunk :P

[@bmwi3diy782]

Well, the original plan was to use the small Ecoflow River2 plugged into the 12v car socket to charge while i3 is "still alive", so the electric blanket & fridge can stay powered on until the next preconditioning cycle, but your idea is probably simpler & would work as well. I like the idea of having it close to the coffee maker! One advantage of the TEC fridge over compressor is that it can be laid flat in the back too if space is limited.

[@bmwi3diy782]

I found some data on an Alpicool C15 that says it can run at 312watts over 24 hours (13watts avg), so that is a bit better better than my data (must have a very low duty cycle Vs my 50% duty cycle), so you are right. I also found a note that said the startup power can surge as high as 150 watts. At the lowest setting of -20C the reviewer said it consumed 610whrs/day (about 25watts, but that's cold!). There was one mention on a review site that said that small fridges are not necessarily more efficient, showing the C22, C45 units at about the same power consumption! Overall, if you have the space and budget, the smaller compressor fridges look like a good option. Thanks for the feedback!