DIY running 240v caravan off a 12v battery

[Silveredition]

Hi all,
I have been a caravan hater for years - preferring swags and tents, mainly due to towing my boat everywhere we go…. My wife and I have, however, just purchased her parents Coromal Seka 17ft caravan.. the intention is for trips of 2 or 3 nights at campgrounds or caravan parks in the south west of WA as places like Margaret River, Augusta, Denmark, Busselton etc are all within a couple of hours of home.
The van is set up to plug into 240v power (only a 240v fridge) at a caravan park, which is how my wife’s parents used to use it, but I am keen to be able to camp at places without power for 2 or 3 nights (without a generator).
I am thinking (and open for options!) of buying a 300ah Kings Lithium and a 1500 / 2000 / 3000 watt Kings inverter, and simply charging the battery off mains power prior to going away, and plugging the extension lead from the inverter to the caravans 240v input once at a camp site…
Have I missed anything, or would this work??
I have an Engel in the car, so am happy for the fridge to be off for the 2 or so hours until we get to camp, but would also be interested in getting an electrician to wire in a 2- way switch so the fridge can be on when travelling (not keen on an extension cord around the outside of the van when travelling!!!
In the future, depending on use, I will also add solar through a Victron mppt…
Please don’t comment on the Kings brand… at the moment I am only interested in hearing if my thinking will work - maybe Renogy / Itec / Redarc(!$$!) will be brands I end up with….
Any suggestions would be great - but at the moment this is a ‘cheap as possible’ setup!

 

[cookie64]

Honestly, probably not what you want to hear but... Ditch the 240Vac Fridge and replace it with a 12Vdc, inverters are inefficient and will drain a battery quickly.

Just my thoughts

cheers

 

[discomatt]

As Cookie stated you are possibly better off to get a new fridge, inverters do draw a fair amount of power, but if you added a decent size solar panel you would / might get away with it on sunny days. Depends on fridge draw.
Like everting in life , there is the right way and the wrong way, the wrong way may work but it’s not as well or reliably as the right way

 

[cookie64]

As Cookie stated you are possibly better off to get a new fridge, inverters do draw a fair amount of power, but if you added a decent size solar panel you would / might get away with it on sunny days. Depends on fridge draw.
Like everting in life , there is the right way and the wrong way, the wrong way may work but it’s not as well or reliably as the right way

Would want to be a mammoth Solar Panel with an incredible MPPT Regulator - it may pull 100 - 200 Amps per hour running not allowing for the inefficiency of the Inverter - depending on the fridge size and duty cycle of course.

 

[Albynsw]

I think you should just bight the bullet and put your money towards a 12v fridge if you dont intend on staying at powered sites. Sure you can get a system up and running with inverters and battery banks but you will find yourself looking for a 12v system not far down the track as it wont be efficient enough and you have wasted your money

 

[CTL]

What you are suggesting will work. Just make sure your 240/12 volt charger is not being powered by your inverter as it will be in a loop achieving nothing. Also make sure your 240 volt hot water heater is also not being powered by your inverter.
Cheaper inverters are usually more inefficient than better engineered ones. The cheapies use older technology hence why they are cheap.
Lots of people using newer technology 240 volt digital inverter compressor upright fridges and power them through a 12/240V inverter. With this newer technology they are pretty efficient.
A 200 litre upright 240V fridge will use less than 3 amps per hour with a 70% duty cycle so about 50 amps per 24 hours plus the inefficiencies of the inverter etc. Work on 55-60 amps per day drain from your battery.

 

[Colly18]

Hi all,
I have been a caravan hater for years - preferring swags and tents, mainly due to towing my boat everywhere we go…. .........
Any suggestions would be great - but at the moment this is a ‘cheap as possible’ setup!

First up, how big is your Engel car fridge. We (2 of us) can easily survive a week with just our 50 litre Waeco set at 3 degrees C., using car charging and solar to keep the power up. Let's assume you want a little more fridge space than your Engel can provide, and you may be away from 240v power for 2 or 3 days. We had a similar dilemma recently, contemplating that (with longer trips out bush) it would be good to have more fridge space. Cheapest option was to purchase a Kings 20 litre 12V compressor fridge/freezer on special for $250 delivered (with a cover). So maybe keep the fruit and veg/salad items in the Kings and the meat, milk and drinks, etc in the Waeco? Reviews were pretty good on this size Kings 12v fridge/freezer and we gave it a good test at home to confirm it was functioning well. If it stuffs up, then it's no dramas, as we have the Waeco backup. Carry a decent fold out solar panel setup (or roof mounted one) as required.

 

[Silveredition]

Thanks for the replies… After thinking about it, and looking at the modifications necessary, we decided against buying the caravan, and will stick to a tent… The van really didn’t suit our needs and ended up being too complicated to carry out the required modifications to suit us (so now I am assisting my Father in Law to sell his 1991 17ft Pop Top Coromal Seka in immaculate condition - $12000 if anyone is interested)…
We will stick to tents and swags for the time being…

 

[jowzia88]

The tent is also a good idea, happy for you.

 

[Lost1?]

Good result. Enjoy what you have.