[Closed] Solar powering a fridge/coolbox

If you had say 12 hours good sunlight and 12 hours nothing then your panel would need to be at least 2x65w to both drive the fridge and charge the battery to run it when there was no sun.  Then when there was no sun you need at least 12x 5.5A say 70Ahr battery to last 12hrs but actually probably twice that as you should never flatten them.  Better using a proper solar battery than car battery as they are designed for deep discharge rather than high current

I think

I can't see solar providing close to enough power to keep a fridge cold. If by fridge temp you mean 4-5C.

I suspect 65W is just to maintain the temp and it'll use a lot more than that to get it down to temp initially which is where solar panels would fail.

I have 285w of panels on my camper which will run a proper compressor fridge + USB chargers etc 24x7 in UK summer, but not winter (it'll take the edge off but the batteries (2X100A) will be run down in a few days. It'll run it 24x7 in south of france winter.

With a non-compressor cool box you've not no chance with 65w channel.

A 12v coolbox won't actually lower the temperature in any meaningful way.

It works on being cold or ice assisted and keeping it there or at least slowing down the heat up.

I have 2*150watts of solar and 2*120ah batteries in the van. I still don't use 12v on the fridge as even on the brightest days it takes all of the watts and it's just much more effient on gas

What you want is a 12v compressor fridge but your probably looking at a best part of a grand to set your self up with a system that will work.

If it's only for a week or 2 gas really is your best bet if you want stuff to be cold cold .

Look for a "3way fridge" folk used to pretty much give them away from caravans as the vanlife crew want no gas appliances for some reason. - they are enjoying a resurgence now due to shortages of the alternatives.... I'm showing 15-20 for about 100-150 quid on Facebook market place

I have 200w of Solar running a Weaco compressor fridge, 80 litres. I leave it running all summer, and the inside of the van gets hot in the day so it works fairly hard.

However, once you've factored in the cost, bulk and weight of panels and the battery, I'd just get a gas fridge and gas bottle. Either a gas coolbox, or a 2 or 3 way second hand caravan fridge. If you get a caravan fridge, you need to box in the back so warm air rises and exhausts out the back and it must be in an open sided shelter to avoid dangerous fumes (same as a gas coolbox)

Got to agree with 12v fridges not doing much apart from cooling things a bit.  If you are close to said granny maybe you are better with one of the super cool boxes and then replenishing cool packs from granny's house every day or two.

A 12v coolbox won’t actually lower the temperature in any meaningful way.

They do, if it's not super hot. Usually about 16C below ambient which in current weather is good and cold. Suitable for drinks etc but not reliable enough for meat long term. But ok to keep meat cool until dinner.

One with a thermostat is better so you could stop it freezing stuff overnight.

it’s s france

Ah. Then it won't be so ideal.

I know someone who lives off grid who does this but they had to buy a fancy waeco compressor fridge.

Agreed - Old Skool 12V is not the way to go unless you are prepared to run it on gas. Compressor fridge and enough batteries and enough panels is $$$ for few weeks holibob.

Up until 25 years ago all but the fanciest yachts in the med (the inside of a yacht in the med during the day needs experiencing to understand) with a medium sized top loading coolbox built into the galley worktop and a sodding big block of ice dropped in the bottom, replenished whenever you got a chance (every few days). You taught people that it was not a fridge and it was opened on pain of death unless absolutely necessary and all was good with the world.

Buy a big coolbox and put a drain hole in the bottom if there is not one already (and position it somewhere where the melted icewater can drain out). Buy half a sheet of kingspan or similar and a roll of gaffer tape and make your cool box a little insulated jacket/box, included an insulated lid cover. Then bug some ice in the bottom every few days and learn to live frugally. Buy everything from the cooler section so already cold if possible.

edit to add - camp on an allotment all summer? Would that not be a hanging offence by the old boys in the UK? They might literally have pitchforks!

They do, if it’s not super hot. Usually about 16C below ambient which in current weather is good and cold. Suitable for drinks etc but not reliable enough for meat long term. But ok to keep meat cool until dinner.

Over about a fortnight of not being opened it might get to 16 below ambient if it wasn't started cold or assisted with ice.

Let's remember that the peltier coolers found in non compressor units are ~c 15% as efficient at cooling as a reverse carnot cycle refridgerator. Your 65w won't go very far

Just buy fresh foods daily. Your on holiday, you will have time.

Evaporation fridge? Might at least help keep stuff fresh till tea time.

More details here…
http://rebuildingcivilization.com/content/build-evaporative-refrigerator-no-moving-parts-no-electricity

Doesn’t actually cool very much but might be a nice project anyway.

I did the maths on this when building our van (somewhere there is a thread on it) and the summary was we ended up buying a Dometic 12V compressor fridge which happily runs off our 160 W solar in the summer (and solar charged battery overnight). Our old powered cool box just hammered the power and like the comments above, wasn’t good for keeping diary or meat until anything but that evening.

This is a timely thread, as I'm just looking at getting a some solar stuff for our van. We have a 'fancy Waeco compressor fridge', which is 45W and draws between 0.6Ah and 1Ah according to the spec sheet. It's switched off at night (say 10pm to 9am)

There's very little else in the van to be powered - a couple of LED strip lights that might be on for an hour a day, a tiny water pump that's run for about 30 seconds a day and charging of phones occasionally. It's all driven off a 110Ah leisure battery, which is fully charged from the mains before any trip

So, I was planning on getting a 100W 'suitcase' panel, as I figured that will easily do us for a long weekend (the battery itself will normally do that), and will probably just about do for week-long trips in the UK, and definitely fine in sunnier climes. Sound reasonable?

Thinking about this again.....this might work.

A bog standard ebay bought 2nd hand 240V undercounter 'granny' fridge
A 160W panel and mppt controller
Some over engineered and chunky cables as short as possible (to improve efficiency)
A leisure battery
A inverter capable of handling the peak power needs as the fridge turns on.

I reckon if buy well with the fridge in terms of efficiency, you mount the solar panel at 45% in the right direction in direct sunlight (a sizable efficiency improvement over a flat mount on top of a van) and you promise yourself you won't open it more than needed you might blag it working without an expensive 12 compressor fridge in a bit of the world you are going to be.

That 100% works convert but you'll need more than one leisure battery .

hinking about this again…..this might work.

A bog standard ebay bought 2nd hand 240V undercounter ‘granny’ fridge
A 160W panel and mppt controller
Some over engineered and chunky cables as short as possible (to improve efficiency)
A leisure battery
A inverter capable of handling the peak power needs as the fridge turns on.

I reckon if buy well with the fridge in terms of efficiency, you mount the solar panel at 45% in the right direction in direct sunlight (a sizable efficiency improvement over a flat mount on top of a van) and you promise yourself you won’t open it more than needed you might blag it working without an expensive 12 compressor fridge in a bit of the world you are going to be.

You'll need a AAA+ rated fridge e.g. https://www.inventorappliances.com/compact-and-mini-fridges

A pure sine wave inverter man enough for the start up load e.g. Victron 12/500 Phoenix

A deep cycle leisure battery and enough solar to charge it through the day.

Have a read:

https://www.vwt4forum.co.uk/threads/home-fridge-in-camper.1359314/page-4

That 100% works convert but you’ll need more than one leisure battery .

I'm not sure. Depending of the size you might blag it with one. You've only got the one night to get through until the next charge. Safer with more obviously.

The Hyundai Ioniq 5 comes out soon. Get one of those, you can just plug normal 240V appliances into it. Just make sure you get out and charge it every few days 🙂

Thinking about it, even our normal Ioniq has an option to run the 12V socket off the main battery for camping etc. It has a 38kWh battery, so it could run a 65W fridge for ... *sound of calculator tapping* ... three weeks ish whilst leaving you enough power to drive to a nearby charge station.

38kWh battery, so it could run a 65W fridge for … *sound of calculator tapping* … three weeks

Provided you don't open it it should be about 15 below ambient by then

I was looking at these to go in our camper.

https://www.amazon.co.uk/Alpicool-Refrigerator-Portable-Camping-Electric/dp/B08F76NKSG

Having said that, I've got 200w of solar, and 220Ah of batteries.

Even going budget build with that fridge and some cheap batteries and panels, I reckon you're well over £500.

Other considerations with a home style fridge... Are the shelves going to rattle constantly or fall to the bottom of the fridge, is the door going to fly open, is it going to work when you park on an incline, and is all your food going to slide off the shelf and fall out when you open the door. All of these issues are covered with Waeco style fridge...it's even got a divider in the door so your milk/wine can't fall over.

* Obv not applicable to the OP as he's camping, not campervanning...

A 12v coolbox won’t actually lower the temperature in any meaningful way.

It works on being cold or ice assisted and keeping it there or at least slowing down the heat up.

My Halfords coolbox disagrees. I've run it in the back of the bus for days at a time and in a caravan (where it was admittedly at least part insulated) for longer. Doesn't need massively chilled down beyond an hour or so running before putting cooled stuff in.

Don't know how it would handle continental temperatures (badly I'd assume) but they're really not as bad as is being made out.

I have a 160W panel, 110ah battery, Victron MPPT charge controller and a 12v compressor fridge in my camper conversion that happily runs full time during the summer months. I didn't bother with hook up as this is all the battery has to cope with, well and a few LED lights that use naff all.
A decent panel and controller will make a difference.