Morning everyone, I just thought I'd write up a little review on how I have made a counter top fridge/freezer into a 12v compressor fridge for a fraction of the cost, I will be honest this set up will use about 25% extra power compared to a purpose-built but the whole set brand new only costs £171. But it is possible to make for a lot cheaper as mine only cost £80. The set up First I found a counter top freezer on Facebook for £20 the reason I went for a freezer over a fridge is because the freezer is a little bit better insulated save a few amps. Then I bought 1100 watt inverter stay away from the "ebay £25 jobbies" there power rating is that of fiction spend about £80 on a decent one. It needs to be no less than 1000watts because when a fridge kicks in there is a big 600-700 watt draw for about max 10 seconds then mine goes down to about 80watts Then finally you'll need a thermostat switch to kick the power on and off. Here i went for a mechanical switch because it doesn't use any electricity again trying to save any amps I can. But an electronic one will get you better accuracy and allow you to see the fridge temperature Here you can wire the thermo switch either to a large relay to the power cable turning the inverter on or off this is the most efficient way depending on the type of inverter you have. But I had to wire mine to the fridge cable because when my inverter get power it doesn't turn itself on. So near the plug I cut about a 5cm section out to get access to the brown live wire I then cut this. Soldered a wire going to the thermostat switch then back again. This might not help anyone but I just thought I would share this with people its a fun little project that could save people some money. It you have any questions let me know
Sounds like you’ve been busy. 80 watts is over 6.5 amps on 12 volts. Is that constant? If so great for travelling. Not so much when camped and a couple of amps less than an absorption fridge but significantly more that a quality proprietry unit ( possibly running at 2 to 3 amps but only intermittently.) not dissing just not convinced.
I did a little test run last night in the house because I still have my old absorption one installed, what a nightmare of a fridge that is it works if I'm 100% level drives me round the bend Anyway my rooms was 17°c inside fridge was 15.2°c took 20 mins to get down to 2°c then took 2 hours before it went back to 6°c when it kicked back in. But this time is completely dependent ambient temperature the hotter it is the fast it will heat up
Some inverters will have remote enable switches. Others, you can put a couple of wires across the inverter's enable switch. If you use a pure sine wave inverter, the fridge will run quieter than with a cheaper inverter. Quite often the big inverter is actually two half-sized inverters in the same box, the second one only comes on when the load gets really high, which improves the efficiency. The fridge only has to run for part of the time at 80 watts unlike the absorbtion fridges. BUT if you cannot turn the inverter off, the inverter's standby power consumption may equal the average power consumption of the fridge, so it will actually use twice the power that a 12 volt compressor fridge uses.
Excellent point there are alot of things to consider when doing this, i personally when for KRIËGER 1100w inverter because amazon had a returned one for £50 it also should only draw half an amp in standby mode. what I gain from this route compressor fridge plus 240v in the van for £80 for me is idea because I do a lot of off grid camping by that I mean I love me a good lay-by.
