Battery or Gas for fridge ???

[Gina M]

Hi everyone. We are going to be staying on a field for 3 days with no EHU. I was wondering if it is best to put the fridge on gas or run it off the battery? We have solar panels on the roof of the van. Sorry if it's a stupid question, Steve says to run the fridge on gas but I am not sure.

 

[Marty Gilly and Pup]

Gas gas gas until it runs out. Then go buy more gas.

 

[stevewagner]

A normal 3 way fridge usually only runs on 12 volt when the engine is running. We always run ours on gas when off grid.

 

[Spriddler]

I'd always use gas as the fridge is more efficient on gas than 12v from the (unstated) capability of your solar/hab battery(ies).
Besides, most motorhomes are set up to run the fridge on 12v only when the engine is running as the current required would flatten a single fully charged battery in around 4 to 6 hours.

 

[bigwood]

I might be wrong but the fridge can only be run off 12 volts if the engine is running, it is with ours.
When we are off grid without hook up we run the fridge, heating and hot water on gas.

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[tacr2man]

Run it on gas as it is not very efficient on 12v as it is absorption type fridge as Spriddler says

 

[Off da Grid]

If you want to save gas turn it off at night. It’s an insulated box after all
When ours wasn’t working on gas we used freezer blocks changed twice a day. Refrozen in the site freezer.

 

[Gina M]

A normal 3 way fridge usually only runs on 12 volt when the engine is running. We always run ours on gas when off grid.

Thanks, it's the first time we have gone without EHU for 3 days and I am really nervous about losing all of the food I have packed in the fridge and freezer.

 

[Pausim]

Gas. A 6kg bottle of propane contains 84kWh of energy a 100Ah battery is about 1.2kWh.

 

[stevewagner]

Thanks, it's the first time we have gone without EHU for 3 days and I am really nervous about losing all of the food I have packed in the fridge and freezer.

Fridge on gas will be fine

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[Spriddler]

Thanks, it's the first time we have gone without EHU for 3 days and I am really nervous about losing all of the food I have packed in the fridge and freezer.

According to the manual my Dometic 3 way fridge uses 187-257 grams of gas per 24hrs based on 25C ambient temperature.
The level of consumption depends largely upon how often you open the fridge door and how much shopping stuff at ambient temp you put in it. I always take stuff from the fridge at the last possible moment and return it to the fridge as soon as I can. I never leave the door open, even if just taking out the milk to put a splash in my tea.

 

[Smudger55]

Having learnt that you use gas rather than batteries, I was surprised to to learn this, when not on EHU, roughly how long would a say 6kg gas bottle last if you cooked, heated and used fridge?

Don't you know also worry about lpg supply, but then running battery down not good either.

So if you are away from EHU doesn't it become a "stressful" experience?

Sorry I'm interested to know life without EHU as we have never tried it. Cheers Smudger55

 

[Gina M]

Having learnt that you use gas rather than batteries, I was surprised to to learn this, when not on EHU, roughly how long would a say 6kg gas bottle last if you cooked, heated and used fridge?

Don't you know also worry about lpg supply, but then running battery down not good either.

So if you are away from EHU doesn't it become a "stressful" experience?

Sorry I'm interested to know life without EHU as we have never tried it. Cheers Smudger55

I am about to find out !!! getting stressed already, not even there yet!!!

 

[stevewagner]

Looking at the post above a 6kg gas bottle would keep the fridge going for 24 days so if you factor in cooking and heating should last at least a week but would depend on how long the heating is left on for. We have 2 x 11kgs Gaslow and have never run out. We camp in all four seasons and rarely have EHU. We do have 2 x 100amp lithium batteries as well so are pretty much self-sufficient.

 

[TheBig1]

We have always rallied away from electric hook up, even long before solar panels were cheap enough. We could go 10 days on one battery and longer with a 6kg cylinder (up to 14 days). Now with solar, indefinitely on 12v but gas remains limited

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[Spriddler]

Having learnt that you use gas rather than batteries, I was surprised to to learn this, when not on EHU, roughly how long would a say 6kg gas bottle last if you cooked, heated and used fridge?

You can obtain the gas consumption rate from the manual for the equipment. You then have to make an assessment depending upon how much cooking/heating you do and how much hot water you use.
I have two 6kg Gaslow refillable cylinders and over time I've gathered a good idea WRT how long on average one will last before I have to change to the second one. In 9 years with that set-up I've never run out completely and hardly ever have EHU.

 

[Gina M]

What this space if this trip goes well without EHU, then I will agree to go without in future

 

[Spriddler]

What this space if this trip goes well without EHU, then I will agree to go without in future

It's my experience and it seems to me from various posts about fridge performance in general that in hot weather they cool just as well (on gas) at a lower setting (e.g. on number 5 or 6 out of max 9 on my dial) than at a higher setting. I'm a bit fussy about food hygiene/safety (esp. chicken) and have a thermometer in my fridge and at mid dial settings it remains at between 2 and 5 degs. Any lower than 2 deg and I risk frosted cucumber syndrome.

 

[Lenny HB]

I might be wrong but the fridge can only be run off 12 volts if the engine is running, it is with ours.
When we are off grid without hook up we run the fridge, heating and hot water on gas.

Every van we have had fridge runs off the cab battery with the engine running & without the engine running you can select 12v and it will run off the hab battery.

 

[Spriddler]

Every van we have had fridge runs off the cab battery with the engine running & without the engine running you can select 12v and it will run off the hab battery.

Yebbut, you have so much solar that you sell your spare to the National Grid.

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[Gina M]

It's my experience and it seems to me from various posts about fridge performance in general that in hot weather they cool just as well at a lower setting (e.g. on number 5 or 6 out of max 9 on my dial) than at a higher setting. I'm a bit fussy about food hygiene/safety (esp. chicken) and have a thermometer in my fridge and at mid dial settings it remains at between 2 and 5 degs. Any lower than 2 deg and I risk frosted cucumber syndrome.

I have it set on high at the moment while on hook up at home. When we leave I will turn fridge down to lowest setting as it will be so cold I am confident it will keep the food safe for the journey. Food hygiene is my main concern too. I have had food poisoning twice in Thailand and India

 

[Gina M]

Every van we have had fridge runs off the cab battery with the engine running & without the engine running you can select 12v and it will run off the hab battery.

But for how long, that is my worry.

 

[Spriddler]

I have had food poisoning twice in Thailand and India

That's probably due to relying too much on GPS.

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Incidentally, when I'm driving and my fridge is on 12v it isn't thermostatically controlled and only just about maintains the temp it was at when on 240v or gas regardless of the dial setting. I think it's the same for many (most?) fridges on 12v when driving. Your fridge User Manual should have that information.

 

[TheBig1]

I have it set on high at the moment while on hook up at home. When we leave I will turn fridge down to lowest setting as it will be so cold I am confident it will keep the food safe for the journey. Food hygiene is my main concern too. I have had food poisoning twice in Thailand and India

I am fully aware that some folk don't understand it, but putting the fridge on full is actually counterproductive. Absorption fridges work by applying a small amount of heat to the sealed system, causing the liquid to gas off and so cooling the inside of the fridge. Too much heat and it actually warms up too much causing the fridge to warm above ambient temperature

Setting the fridge to half way at most works best

 

[TheBig1]

But for how long, that is my worry.

running a fridge off the hab battery will flatten a 100ah battery in less than 10 hours. If you have LOADS of solar it can work in daylight, but needs a relay fitting to cut the feed if solar can't keep up with the supply need

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[rb62]

But for how long, that is my worry.

Run it on gas when not on hook up then you won't have to worry!

 

[Lenny HB]

I am fully aware that some folk don't understand it, but putting the fridge on full is actually counterproductive. Absorption fridges work by applying a small amount of heat to the sealed system, causing the liquid to gas off and so cooling the inside of the fridge. Too much heat and it actually warms up too much causing the fridge to warm above ambient temperature

Setting the fridge to half way at most works best

I know a lot of people say that but I've never found it to be the case. I've only had the big fridge/freezers in Motorhomes and turning them up higher the colder they get.

 

[Lenny HB]

But for how long, that is my worry.

I said I can turn it to 12v didn't say I did. Mine takes 14 amps on 12v.

Mine is set with a solar regulator that gives a signal to the fridge which makes it switch to 12v when the batteries are charged and there is enough solar. It does it in 30 min bursts so as not to flatten the batteries.
I have 300 Watts of solar and 3x78ah gel batteries.

 

[Toady]

I run my fridge on hook up before leaving home with freezer packs in ice box.

When travelling, I am on 12v.

When parked up off grid then if sunny, I use 12v but if cloudy then on gas.

My tip is to place the freezer packs in main fridge area during the day and move back to freezer overnight.

Also, add an external fan to your fridge vent and an internal fan in the fridge.

I have added temp gauges to the fridge and freezer so I can monitor without opening fridge door.

 

[PaulOH]

Many different viewpoints from MHers with many different setups - all of it very informative!

I once parked for 1.5 hours in the middle of a 5 hour drive and forgot to switch off the battery . Before we resumed the journey I noticed this and checked the leisure battery button on my Austin Maestro-esq electronic control panel, which gave me a red light - this was following 3-days off-EHU - so not very surprising.

The second leg of the journey was higher speed and motorway cruising, fridge on the battery again, and the (titchy) freezer-box was starting to freeze an icepack by the time we got home, battery button giving a strong green light!

I was so happy!!