How long can i run a fridge of battery

Hey guys, I am looking at picking up a Waeco CF40 whilst they are on special ($500) but was wondering how long I can run it off a battery for. I If required I think I can squeeze a second battery next to my main (if i rotate it 90 degrees) and that should be fairly cheap, but I was wondering how long I would get off that or if I would have to go solar to run it for any decent amount of time.
I looked around but was still confused as I have no idea how power ratings and such convert into actual time.
 

REDDOG IAIN

New Member
Depends on how much you use it in a day, a compressor fridge will easily consume 60-70 amps 24 a day, get another battery and make sure it is wired in such a way that they are both charged but only one is drawing power.
 
Depends on how much you use it in a day, a compressor fridge will easily consume 60-70 amps 24 a day, get another battery and make sure it is wired in such a way that they are both charged but only one is drawing power.
Don't you just leave them on all day? I'm wondering if I could get 3 days max, but more likely 2 days.
 
Depends on how much you use it in a day, a compressor fridge will easily consume 60-70 amps 24 a day, get another battery and make sure it is wired in such a way that they are both charged but only one is drawing power.
Don't you just leave them on all day? I'm wondering if I could get 3 days max, but more likely 2 days.
So I guess i'll get about a day and a half from a 100AH second battery...
 

cam04

Well-Known Member
If you have the contents already cold and the battery is a fully charged 130 ah then you should expect 2-3 days without recharging unless you are on Groote at Christmas time - hot.
 
If you have the contents already cold and the battery is a fully charged 130 ah then you should expect 2-3 days without recharging unless you are on Groote at Christmas time - hot.
Cool. It would be fine if it ran out at some point on the 3rd day as long as it made it to somewhere around 11AM anyway.
I'll now have to see if I can squeeze in a second battery or not. I assume I need a deep cycle, anything else I should watch out for? Any other rookie mistakes that I can make (because I will)?
 
D

Deleted member 69390

Guest
How long is a piece of string - usage comment above related to open and close the lit and letting the cold out - not switching them on and off.

How long is that piece of string - depends on type of battery, condition of battery, battery capacity, temp the fridge is set up - use as a freezer or just a fridge, outside temperature, does it have an insulating cover, location of fridge undercover or in light (sun), in a closed car or in the open, day time or night time, how much you open or close your fridge, size of power wiring and it goes on and on.
 

unko84

Active Member
It sounds like your only going to be putting a 60ah battery in the small space. depending on the battery you should only use between 30 to 50% Maximum of your batteries if you want longevity in your batterys, more then a year usage.
an avg. fridge uses about 5 amps per hr ??during the day and about half that at on a cool night
go over kill on the wiring thicker the better at conserving your amp hrs, less stress on the motor in your fridge so uses less power
 

cam04

Well-Known Member
Cool. It would be fine if it ran out at some point on the 3rd day as long as it made it to somewhere around 11AM anyway.
I'll now have to see if I can squeeze in a second battery or not. I assume I need a deep cycle, anything else I should watch out for? Any other rookie mistakes that I can make (because I will)?
Correct isolation system for your car, heavy enough cable to charge and run the fridge, tie the battery down correctly etc. etc. Most info can be had online. Post up what you propose to buy first and the local experts will all give opinions.
 

peterfermtech

Well-Known Member
One of those fridges at around 25 deg. you can work on about 40 Amp/hr per day if in the shade and not in the car. A 100w solar panel can keep up and probably cheaper than a second battery.
regards
 
@peterfermtech Problem is that that only covers me during sunlight whereas a battery I'm hoping will last a while.
@cam04 I only have a 2006 Kia Sorento and where the battery is now, should allow me to rotate it 90 degrees and just fit between the fuse box and the engine cover\shroud. Then it would be a simple matter of making a bigger base plate to fit 2 on. I hoping that this will be the simplest solution to get a second battery underneath. Its hard to see in this image, but you can kinda see there is plenty of room around the current battery. I don't want it inside the car because it's still so nice and new in there (plus I already have trouble fitting everything else in there). I don't actually know what size my current one is, so hopefully, I can fit something with a decent life in there.
I'll also look at a dual battery isolator (or whatever they are called) from 4wdsupercenter or equiv.
https://imgur.com/a/TGosKSj
https://imgur.com/a/k74haMs
@unko84 What dies when you run the battery down 100%? Can I just add more acid or does the actual battery die? I'll probably only use it around 4-6 times a year, would that make a difference?.
 

Aaron Schubert

Moderator
There are a lot of variables when it comes to fridge consumption, with the main two being the make and model of the fridge and the ambient temperature it is running at. A decent fridge around that size under 30 degrees ambient temperature shouldn't use more than around 30 - 40 amp hours a day.

Normal deep cycle batteries have a cycle life of about 1500 times, when you only use 30% of their capacity. Take it down to 50% and you halve that. Go lower and you get much less cycles - essentially the more power you use the the shorter the battery will last. Essentially a 100 amp hour battery is only good for 50 amp hours if you want to preserve its life.

Maybe you should look at a portable battery pack that can be removed, and just plugged into the back of your vehicle.

Aaron
 

cam04

Well-Known Member
You won’t get a full size battery in there. Maybe get the biggest you can and supplement it with one of those folding solar panels from the super centre. They do 120a panels at a decent price. If you can’t have a big puddle of power you can keep trickling some in to maintain a smaller puddle. Cheers.
 

peterfermtech

Well-Known Member
You need a battery of minimum 80A and a 100 watt solar panel. A 100 watt solar panel will during sunlight hours replace the power you use all day.
Alternatively get a 130 Amp battery which will last you 3 days and expect to throw the battery away after a few years. Still a cheaper and better alternative than buying ice.
regards
 

itlldoo

Well-Known Member
fridge temp management is the key, you just do things different with the power supply you have.
one battery, never put warm or room temp items in it , draws heaps to get things cold, pre freeze long term meats and place in the bottom, limit the opening and closing and turn it off overnight and drive for a little while during the day all should be good.
two batteries, allows you to go for longer without starting your car ( 2-3 day camps) but still some management required,
two batteries + solar+ management = 4-5 day camps with no driving is possible, overcast days will change things a bit with the recharge.
the best i have had, is using the fridge as a freezer pre charge your fridge, ie get it cold on 240 power before you leave and pre freeze your meals have a esky or cool box for the food for the day and transfer frozen food as you need them, using this method i did 5 weeks up the cape on a crank battery with no solar and the 40L Engal never skipped a beat. if your going longer and need to refill your frozen stuff i found most butchers will cry-vac and freeze stuff overnight if asked for pick up the following morning. so with just a bit of management one battery and one fridge is doable.
 
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RDM

Active Member
To give you and idea I can run my 50l Waeco CFX off my 120ah second battery for about 2 days in the middle of summer and about 4 in winter on average but this is very dependant on what is in the fridge how many times its opened I also run lights ect and am not too conscious about power consumption so I could probably get it up some without too much issue. Also the battery is about 50%bigger again than the battery in your picture so I doubt you could get a battery of any decent capacity in there to be honest. A removable power pack such as an ark pack is probably your best option.
Personally I would avoid running a fridge off your start battery for any extended period with the engine off.
 
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