#148330  by LordCrumb
 Sat Jan 19, 2019 8:25 pm
Hi everyone!

New to the camper world.. currently working on converting my van into a half camper, half work van for when I work out of town.

Regarding fridges, how do these get powered? do they run off an inverter that's on all the time, or do they get wired into a second battery? I have a Deep Cycle Dual Battery Isolator setup for a couple of lights and a 12v TV, but was just curious if there was a particular fridge I needed to get.. but if its run off an inverter, it wouldn't really matter would it?

If anyone has any recommendations for a fridge brand/model that would be helpful too. Sort of 'bar' size, but large enough to hold lunch/dinner items plus a couple of bottles of water?

Thanks!
 #148333  by Growlerbearnz
 Sun Jan 20, 2019 7:03 am
IN general there's 2 kinds of fridge used in a motorhome:
-compressor fridges (Similar system to your home fridge, runs off electricity, usually 12V and 240V so often called "2-way" fridge)
-Absorption fridge (burns gas to power a complicated chemical cycle which cools the fridge. Runs off gas for ages, will also run off 12V or 240V using a heating element instead of gas- but it's very inefficient running off power. Often called "3-way" fridge)

There's a good run down here: https://www.caravansplus.com.au/guides/ ... -a-75.html

Which one you choose depends on how much power you have. 3-way fridges are great for smaller caravans or for a budget fitout, since they don't require solar. A compressor (2-way) fridge will cool faster, but you need about 400W of solar panels and minimum 200Ah of battery just to run the fridge, so it gets expensive fast.
 #148340  by LordCrumb
 Sun Jan 20, 2019 11:27 am
Thank you. I have been in a proper, full fledged camper and now that you said Gas, it reminded me that particular one did run off the gas bottles.

I guess I would be worried about safety in a regular van if using that system.. will have to continue research I think :)
 #148345  by Neddy
 Sun Jan 20, 2019 5:00 pm
In comparison with the same capacity 3-way fridge, Compressor fridges are :-
Smaller.
Lighter.
Cheaper.
Colder.
More reliable.
Safer.
Unaffected by tilting.
Longer lasting.
Easier to install.
Cheaper to run (free, once you are properly set up)

An 85 litre fridge draws an average current of just 1 amp. This small power requirement would require a 50 AmpHour battery and a 100 watt solar panel in the Summer or a 150 watt panel in the Winter.
These figures are for the fridge alone but will give you some idea of the modest power requirements of an electric fridge of this size.
Currently I have a 12v 130L compressor fridge and am finding that a 100amp House battery is quite adequate for my needs. I doubt that you need a fridge that big and might well consider that an 85 liter or a 65 litre fridge would suit your needs. The smaller the fridge, the lower its power consumption.

The strongest argument for a 3-way fridge would be if you wanted quite a large fridge and were unable or unwilling to fit sufficient solar power to run it.

With just a few LPG refills costing roughly the same as a suitable solar panel it wouldn't take very long for an electric fridge to pay for the extra solar power needed to run it. Having done so, running costs are effectively zero and you are spared from the very frequent LPG refills that many people are saddled with.

There are many brands of 12v compressor fridges out there, but the best utilise Danfoss compressors and I would suggest that you go for any one of those.

Neville.
 #148348  by Karmann57
 Sun Jan 20, 2019 7:11 pm
What Neddy said. I have a small 12 volt fridge and 100 amp hour agm battery. I have a 160 watt portable solar panel which you can buy off TradeMe for not a lot of money and no installation required, simply clip the panel lead onto your battery.
The fridge runs overnight using around 15 amp hours and the panel recharges the battery by 11:00am on a sunny day and powers the fridge during sunlight hours

https://www.trademe.co.nz/motors/carava ... 6cef917e3e
 #148362  by gmatt
 Mon Jan 21, 2019 9:34 am
An MPPT controller is needed as well? What price do they go for and which is best? thks
 #148364  by Karmann57
 Mon Jan 21, 2019 10:48 am
gmatt wrote:
Mon Jan 21, 2019 9:34 am
An MPPT controller is needed as well? What price do they go for and which is best?
You don't have to get an MPPT controller, the small portable panels come with a PWM controller attached which will serve your purpose. I purchased an MPPT Votronic for possible future instal of a fixed panel on the roof, but the portable unit works perfectly . I have seen some larger more expensive portable panels with MPPT Controlers.
 #148368  by Derb
 Mon Jan 21, 2019 12:19 pm
A real plus with 12v compressor fridge is you dont have to jump through hoops with the gas installer with regard to gas installation regulations for proximity to windows, chimney positioning, sealing cubicle from the cabin etc etc ad-nauseum. It is a bloody minefield. You can do the work yourself with a 12v fridge. Just do the math on "real" costs of supporting equipment for the fridge vs 3-way. Is the battery/solar arrangement going to be up to snuff in winter with little solar available? Cheers.
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