Why should I waste my batteries on a freezer? With 8 hours a day (roughly) solar time and 16 hours too dark for solar any freezer will use power from the battery bank 2/3 of the time and only 1/3 direct from the solar panels. This causes additional power losses in battery charging and also means a shorter battery bank lifetime. I changed my freezer (another Walmart Black and Decker) so that the times are reversed ie. 1/3 power from battery bank and 2/3 direct from solar panels.

Simply purchase a $16 Lowes (20 segment) ELECTRONIC plug in timer. I set mine for a total of 5 3/4 hours in time in the eight hour “day” and then 11 minutes every hour for the other 16 hours. Result is is; 1/3 battery power 2/3 solar direct power. Fluctuation is from -20C (about -5F) to -12C (about +10F. Which is fine for long freeze storage as the food spoiling micro organisms only start to grow again (slowly) above 9.6C ( +15F) so the food is safe. Although some people have remarked that frequent temperature fluctuation can rupture cell walls and spoil taste this is ONLY true when between 0C and 4C when undergoing frequent freeze/defrost at which point the water expands a massive 10% volume (AKA floating Icebergs)and can rupture food cell walls.

Just remember set times to keep max temp below +15F plus some safety margin.

Is your freezer conversion still working? As I plan to something similar…

Cheers

Dermot

My main concern is, what do most people use for a freezer then? Do they go without or do they run a second unit for freezing?

Also, I’ve been looking at Haier chest freezers, but would you suggest anything in particular to purchase?

For your project, I’d try to find a waterproof tub or box that fits inside your chest freezer rather than sealing the freezer itself with caulking. The caulking may eventually leak. If you use the digital temperature controller method, you could put its temperature probe in your water bath and then set it to maintain a temperature just above freezing. That should work nicely.

I like your web site by the way (assuming it’s trilliumhillfarm.com, and not trilliumhill.com!). Vermont looks beautiful, and I’d like to get over there someday. My neighbour’s daughter and her family live on a farm somewhere in Vermont too.

I think the process would be the same as yours except that I am going to have water in mine and will need to seal the joints with caulking. My question for you is did you cut the original thermometer out of the freezer? What was this process like?

Thanks for any thoughts.

Well, well, it seems there is at least one actual manufacturer. Haier apparently sells a lot of products to major retailers like Walmart and Home Depot, so it shouldn’t take much to have them stock it- people just need to ask for it and buy it. Here in Canada, they don’t seem to have them, but I’m going to keep making inquiries until they do.

Have just been reading your website. Just wanted to thankyou. Throughly enjoyed the read. Some great info.

Cheers Patrick

It’s a pity, but then I don’t think they could make them as cheap as my one anyway! It really wasn’t hard to set up, and it’s been working great so far.

Let me know how you go!

I am outraged that this is not made available to regular consumers. Have I just not been looking hard enough, or is the concept of chest fridges really that rare?

I want to try this set up stateside in a camper… I have found a vendor for the Fridgemate MkII in a 110v model, but the description says nothing about whether or not it can handle the kickback of an inductive load. Are you implementing a relay or capacitor to handle inductive load, or does the MkII have a built in capacitor?

I am referencing Tom Chalko’s PDF document from mtbest.net on this subject. Within said document Tom states that the Jaycar WT2300 thermostat he tried first failed after six weeks of use when the relay started suddenly producing large and bright plasma arcs in his kitchen!!

I am REALLY trying to avoid anything that could be a fire hazard, and so the relay contacts must be able to handle inductive load.

It seems a nobrainer… if yours is still working, then it must be able to handle it??