3 Way Fridge Not Working

Sir Liamalot wrote: »

I generally prefer diesel heaters because I already have a big fuel tank I can reload anywhere.

Fair point ... but again, would require a retro-fit (that makes three now, all taking the vehicle off the road, which is a problem in itself).

Sir Liamalot wrote: »

Alternator is standard engine driven one in above references...

Ah, right. But that doesn't do anything when you're parked in a field for six days, so not really relevant to the current discussion.

Similarly, for a retro-fit, there's only so much insulation you can pack into the space available; any increase will require a compromise on storage space inside or outside of the fridge, which - in my case - are both non-negotiable.

The (domestic, compressor) fridge that works for me is declared to use 191 kWh/year, which I assume is based on being housed in a bricks-and-mortar dwelling that tends to remain in the 16-26°C temperature range. That's more likely to be a real-world consumption of an extrapolated 300kWh/an when the appliance is surrounded by air at 30-40°C

So lets say 6kWh for the week in the field, or about 800Wh in a 24-hour period, of which at least 10 hours are dark. That's ... 30Ah from the battery, 30A from the sun-on-the-roof - does that sound right?

D'y'know, SirLiam, you're a terrible man for trying to fit the circumstances to the solution!

Sir Liamalot wrote: »

yer brand new factory fresh job needs a heating, refrigeration and power production overhaul outtov the gates. Throw ~€5k of obsolete inadequate and inappropriate hardware in the skip that was worth about €1k except is was "designed" for the recreational markets so qualified for a 5x performance exclusive markup.

I bought a house and a motorhome at the same time (and for the same price :cool: ) fifteen years ago. The house's heating, refigeration and power has all had to be renewed at a cost of considerably more than 5k, and running costs are considerably higher than a couple of bottles of gas every month (although the house gas bottle does last a longer :pac: ).

So while I accept that much of what goes into shiny new recreational vehicle is overpriced, as far as mine is concerned, all of it has given good service in that time. Of course, the only "fatal" problem was fridge-related, but that was (still is) a critical flaw in the charge relay - the fridge was doing what it thought right, based on false information. Ancient history now, though.

Sir Liamalot wrote: »

You can still turn the engine independently of the wheels when yer desperate although I design to avoid it.

But us lesser mortals have to work with what has already been designed, and in my field, with neighbours at a distance of +/-1m I'd be thrown out of the field with no right to appeal if I ran a smelly old diesel for twenty minutes. So a solar solution has to be a complete solution, no burning diesel instead of gas as a back-up.

Sir Liamalot wrote: »

Arah yee've all got small van problems! Think bigger, buy a truck!

It's not that small - six adult berths, seven belted seats - and functions perfectly well as a cargo vehicle when required. But changing a perfectly good vehicle, more or less designed to order, to accommodate a different type of fridge is not a reasonable proposition, even if I have a current C-licence.

Sir Liamalot wrote: »

First off that sounds like an A-rated fridge.


Get a more efficient one.

Again, suggesting a fridge-no-freezer of half the volume of the fridge-freezer that is just about sufficient for my needs is not an appropriate solution. It doesn't matter how many A-stars that Klarstein model has, it's not going to keep my choc ices frozen, so it's actually worse than the Dometic I'd like to replace.

Sir Liamalot wrote: »

Assuming zero solar or split charge input and a 200Ah battery...let's say 100Ah disposable after lighting etc.. so let's say about 4 days.

You can go around in circles with these things. Since I fitted my compressor fridge I've never worried about powering it or had to turn it off except when it was in storage.

I'm trying to get out of the circle! But working within the real-world constraints of retrofitting into an existing space, my personal requirements in terms of size and style, would you still say that a fridge with a notional consumption of three times your Klarstein example would run happily for two days with a 300W panel supplying 2x110Ah batteries?

I've stepped out of the absorption versus compressor fridge debate but let me give my real-life experience of a B2B charger.
I bought a Stirling B2B 50amp charger over 12 years ago (before solar) to keep my batteries (2X100amp) charged while touring.
I wired it as per instructions with a new dedicated connection from the engine battery and choose 55mm² cable for the job to more or less eliminate any voltage drop.
Result:
After a long night of battery use down to maybe 20% or 25% depth of charge, I get a full recovery to 100% charge after a couple of hours drive and ready for another night of winter off-grid. In such circumstances, my 200watt of solar via a quality MPPT charge controller contributes very little.

A real-life experience:
In 2017 we did the winter markets for ten days in The Alsace during which the daytime temperature hovered around 2°C and nighttime below zero. The heating was on 24/7. During the relatively short drives between the town/villages the B2B kept the battery up no problem. As for the gas, we consumed a full 13kg bottle of propane over six days.

PS. a separate generator or running the engine while stationary is not an option for us due to our social conscience

Sir Liamalot wrote: »

If you connected the 50mm² from your alternator B+ to you house battery across a contactor you'd get a pretty similar result Niloc. I stopped fitting B2Bs because it's the recommended cable does all the work. I've gotten better results by bypassing the £600 boxes.

So what you are basically saying is that a four-stage charging regime (Bulk, Absorption, Float and Equalisation) is of no benefit over a simple alternator charging. Don't B2B units emulate the profile of mains chargers.
I must have something right as my leisure batteries have lasted on average seven years when most fail after three or four with luck.