Fridge and Zig unit are conspiring against me

[keridavies]

Posting this from Alsace on the return leg of my first big Bongo trip. Stops have been a mixture of campsites with electric hookup, basic pitches without hookup, and two stealth nights.

Both the leisure and car batteries are brand new, fitted for the trio.

The fridge is a Vitrifrigo compressor model - which I understand is a good thing - but it's very inconsistent. Sometimes things are fairly cool - although never cold enough to make ice in the little ice compartment - other times it doesn't look like it's working at all.

So, first question: how frosty can I expect my beer to be? Ambient temp has been 18 to 27-ish during daytimes.

With a mixture of hookups and long days driving, I've only once before seen the leisure battery condition lights flicker between the green and the red. That was just before I hooked it up to the mains yesterday evening, after the best part of a night and day when the fridge seemed to run happily on the battery.

Then followed an overnight on the mains, and about six hours driving during the day, with two stops of less than an hour each. But when I returned to the Bingo this evening after four hours on the battery, I was starting to see the green-red flickering again. I was surprised, as I thought it should surely have been brought back to full charge.

So: second question - am I being unreasonable to think that?

I know it's bad for a battery to run it right down, and as it was time to go to sleep, I thought I'd better switch the electrics off completely. I'd rather wake to a bit of spoiled food than a knackered £80 battery.

But despite switching off the 12V circuit, the fridge kept running running! I felt like the Sorcerer's Apprentice. I had to turn the fridge off by its own switch, in fear that it was now drawing current from the car battery.

Could someone explain how it's all meant to work, and suggest what might be going on here?

Sorry for the long post, and thanks in advance.

[g8dhe]

OK, to help we really need to know the make of the power switching unit, is ita Zig if so what version number 1, 8 or 9 are common ? Or maybe a PMS3 unit ?p

[Simon Jones]

If its a Zig CF8 then it has a very crude charging system which you have to change between On Site and Touring to get it to work properly. I've use a separate split charge relay so leave it set to site-mode so it will always charge the LB when on hookup.

Most compressor fridges will happily freeze on the lowest setting. I've managed to freeze a can of coke to the point where it nearly split open with the expansion of the ice.

[briwy]

You may find that the fridge is wired to the Zig unit but to the incoming feed from the leisure battery, ie direct from the LB without going through the Zig. If this is the case then as you say the only way to turn the fridge off is with its own control. I fitted a separate switch in the fridge feed to turn it on/off.

[Jim the Box]

Was than an issue on the bongo you had from Jal, my fridge is not working at the moment and I checked the fuses from the zig unit all seems ok however if I am wired independently from the zig unit I may have a blown fuse or problem elsewhere.