Old 3 Way Fridge/freezer - okay to run on single battery?

Submitted: Sunday, Dec 21, 2014 at 20:31
ThreadID: 110492 Views:3917 Replies:5 FollowUps:8
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Hi guys,
I recently acquired a Primus Snowline 35 from my father. It runs 12 v, 240 v and gas, and according to the back of it, it's 75 watts. I'm going across the red centre next year, and I want to take it with me. I have a Nissan X-trail with just a normal car battery, and I'm wondering if it's able to handle the fridge. My dad had it in his old van and is convinced it will be okay, but we're also running driving lights and a UHF radio so I'm not so sure. When we stop, we will be running it on gas, so that's not a concern. But I'm worried it will sap the battery and I won't be able to start the car one morning.
Any advice would be much appreciated!
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Reply By: Athol W1 - Sunday, Dec 21, 2014 at 21:41

Sunday, Dec 21, 2014 at 21:41
Holly Anne
As long as you are only running the fridge whilst the engine is also running then you should not have any problems during the day. How much night driving do you intend to do, it is not a good idea to be driving outback Australia at night due to the wild life that is nocturnal, and you are not seeing what you went there for in the first place. The only time that you may have any issues is with continuous night driving using all those lights and the fridge, as a 75 watts load from the fridge is roughly equivalent to running an additional headlamp (or leaving a headlamp on after the engine is stopped)

When travelling the outback of Australia without back up it is always a good insurance to have an auxiliary battery system fitted in such a way that it can be used for 'jump starting' or have a good set of jumper cables that can be used with your auxiliary battery to enable 'jump starting' of your vehicle. This auxiliary battery MUST be isolated from the main starting battery when the engine is not in operation.

Hope this helps.
AnswerID: 543235

Reply By: Dennis Ellery - Sunday, Dec 21, 2014 at 22:18

Sunday, Dec 21, 2014 at 22:18
You won’t have a problem if you switch to gas when you stop.
If you forget and let it run off your single battery overnight you will have a dead battery in the morning.
AnswerID: 543238

Reply By: kcandco - Sunday, Dec 21, 2014 at 22:44

Sunday, Dec 21, 2014 at 22:44
Hi Holly Anne

75 watts is just over 6 amps. I have had 4 three way fridges over the years and they all drew considerably more than this, in the vicinity of 10 - 15 amps. I would suggest you check the current draw with a multimeter, just to be sure this figure is correct.

Also definitely have the frig wired so that it is only supplied with power when the car is running. Another consideration is that power current draw will probably be too high to use a cigarette lighter type power outlet. You will need a properly wired supply cable. A cigarette type connector even drawing 6 amps will struggle due to poor connection and may cause voltage drop and overheating (melting) problems in the connection. I have personally had this happen and its not much fun once your on the way.

Cheers Kevin
AnswerID: 543242

Follow Up By: oldtrack123 - Sunday, Dec 21, 2014 at 23:12

Sunday, Dec 21, 2014 at 23:12
HI Holly
Not sure what size crank battery you have ,but if it is the same size as in my Xtrail 2w drive, forget running the fridge off it.
You could end up stuck with a dead flat & stuffed battery.[so much depends on a good battery with the Xtrail,[ as you would know from the manual}
The other point you raised about alternator max output also could be of concern.
There may be little to spare with all the other gear , with electric operated clutch & power steering , air con fan .

The battery is not designed for deep cycle duty, such as putting out 6A all night . You would definitely end up with a flat battery in the morning
To do that every night you would need at least 150Ahr DEEP CYCLE AUX battery.


FollowupID: 830181

Reply By: Tony F8 - Monday, Dec 22, 2014 at 06:46

Monday, Dec 22, 2014 at 06:46
You say you are going across the red centre, but any particular route. I only ask as if you stay on the blacktop you at least will probably have someone come past who can jump start your vehicle. A 3 way fridge will draw down your battery in the xtrail in no time. As mentioned your alternator would possibly struggle to keep up, if you wanted you could fit a low voltage cut off, at least it would save the battery but not the food in your fridge should you ever forget to put it on gas.
AnswerID: 543244

Reply By: Zippo - Monday, Dec 22, 2014 at 12:59

Monday, Dec 22, 2014 at 12:59
As per Athol's response. You only need to forget to switch to gas one night and you're up the creek without a paddle. To be reasonably assured of avoiding that problem, you will need either an auxiliary battery setup OR a jump-starter. The jump-starter involves less work and will cost you less if you hunt down the frequent sales at the auto shops.
AnswerID: 543255

Follow Up By: Gronk - Monday, Dec 22, 2014 at 13:59

Monday, Dec 22, 2014 at 13:59
I went around Australia in a dual cab with a 3 way fridge and NO aux battery...

And because I didn't want a flat battery, I disconnected the fridge every time I stopped ( even for 20 mins ) and fired it up on gas..

I'm assuming everyone can still think these days ??......if so it doesn't take much brain power to remember to disconnect the fridge whenever stopped....or for the ones who can't think....get a relay that switches with the ignition !!!
FollowupID: 830203

Follow Up By: Zippo - Monday, Dec 22, 2014 at 14:31

Monday, Dec 22, 2014 at 14:31
Gronk, you are entirely right. But despite the best of intentions, sometimes - and it only needs to happen once - distractions can cause people to overlook things.

I've done similar trips as far back as the 70's with an Engel MRFT514 in the back seat of a sedan, no auxiliary, no jump-starter (did they exist then?) and no relay for "automation". Only once did I forget to turn it off, when we camped out near Wingellina. Next morning it was a tough push start for the two of us to get going again.

Last trip (this year) was aux+DC-DC+jump-starter. I'm too old for this push-starting crap.
FollowupID: 830204

Follow Up By: Bushranger1 - Monday, Dec 22, 2014 at 15:22

Monday, Dec 22, 2014 at 15:22
I would not run a 3 way fridge on gas inside the back of an Xtrail or any other enclosed space for that matter.

Apart from the build of dangerous fumes there is a real risk of fire.
How do I know that, well one of the guys on a trip with us years back left his fridge on gas in the back of a Hilux with a canopy & when we went off for a walk the smoke in the distance was his car on fire!
We got the fire out but not before plenty of damage had occurred. It seems an aerosol can had leaked then the fridge flame ignited it.

FollowupID: 830206

Follow Up By: Bazooka - Monday, Dec 22, 2014 at 16:42

Monday, Dec 22, 2014 at 16:42
Exactly Stu. Holly won't forget to put the fridge on gas at night because she'll ALWAYS take it out of the vehicle first - assuming she values her truck and possessions. Your friend's unfortunate experience is not as rare as it might seem.

Just to reiterate what a couple of others have said Holly. The thin wiring to power outlets in some of these vehicles is next to useless for 3 way fridges - which are very inefficient on 12 volt anyway. On gas they'll freeze - which is another potential problem if you leave the fridge on high overnight. I'd get a special outlet with a decent plug and heavy wiring fitted - preferably wired to the ignition or via a dashboard switch.

FollowupID: 830212

Follow Up By: Member - kev.h - Monday, Dec 22, 2014 at 21:24

Monday, Dec 22, 2014 at 21:24
Hi Bazooka
Forget the dash board switch only got to forget to turn it off once instead fit an ignition controlled relay then the fridge will only run when the car is running
FollowupID: 830225

Follow Up By: Bazooka - Monday, Dec 22, 2014 at 23:04

Monday, Dec 22, 2014 at 23:04
Depends on how you wire it Kev.Only problem with an illumiated rocker switch is that occasionally you might initially forget to switch it ON.
FollowupID: 830232

Follow Up By: Bazooka - Monday, Dec 22, 2014 at 23:08

Monday, Dec 22, 2014 at 23:08
FollowupID: 830233

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