TheSamba.com :: View topic - 50qt ARB fridge running off the starter battery

Tue Jun 26, 2018 11:36 pm

I just purchased a 50 Qt ARB refrigerator which i will be placing behind the back seat for an upcoming fly fishing trip to Idaho. For this trip I'm going to be powering the fridge with the starter battery. The fridge has a low battery shut off and I'm gong to be driving every day, so i'm thinking it will work fine for this trip.

For future trips I will be installing a second battery under the back seat and maybe using a remote (foldable) solar panel.

What do you guys think and thanks for your input.

Wed Jun 27, 2018 1:40 am

I have the same fridge but it's wired to the house battery with solar.

At what voltage is the low battery shutoff? I'd be worrying about the van not starting at that point. Might be a good idea to carry jumper cables if you're with a group, or a jumper pack if you're on your own.

Either way, before the drive, lower the temp and get it good and cold when you're driving, then bump the temp up when you're parked so it's not cycling on all night. Some ice packs might help.

Wed Jun 27, 2018 4:21 am

I'd have battery anxiety attempting that. A cheap lead acid battery could be added in a half day using a simple continuous relay that energizes when the key is in the run position. Then you can enjoy your trip and build your system when you return. If not I agree with carrying good quality jumper cables or a jump box.

Wed Jun 27, 2018 5:32 am

Well - its doable. The low voltage cutoff isn't really a big deal - actually it may even hurt the life of your battery. My Dometic has different levels and it will damage my deep cycle battery at its lowest setting.

Like MarkWard said, if you have a jump box you should be fine. Hopefully that jump box will recharge through USB cause I have a feeling you'll need a jump after 2-3 hours of leaving your fridge idle in your van. I don't know though...

When you're ready to do your new battery. I would recommend simply an $100 110aH Walmart battery, BlueSeas SI-ACR (80$), and circuit breakers. Don't go Solar into you try this setup. You will need solar if you plan to stay in same spot for 2+ days

Wed Jun 27, 2018 6:45 am

I wouldn't do that. A starting battery will be damaged by doing that. And you may not be able to start your van one mornning. You could rig something up on a temporary basis and just buy a deep cycle battery or at least a marine battery at walmart and run off that. A jump starter pack might be an idea too.

You could possibly put a layer of insulation inside the fridge and freeze things solid in the bottom while driving, then remove the insulation layer and let it work like ice packs. I haven't tried it, but I read about someone who used the bottom section as a freezer, with a layer of insulation in the middle and the non freeze items on top.

Wed Jun 27, 2018 6:53 am

Deep cycling a car battery will weaken it's capacity for it's intended purpose. Just go ahead and purchase a deep cycle battery and install or place wherever on a temporary basis! Place something under it if you have to sit it on the carpet.

Wed Jun 27, 2018 7:23 am

If you're driving everyday you're probably passing gas stations every day or two. Just buy ice for this trip and have peace of mind.

Wed Jun 27, 2018 11:08 am

I have done this with my engle on a 2 week trip a few years in a row. Started the truck first thing in the morning to have the battery charge back up. Having a second battery in my truck would be a PITA.
I have a bigger group 48 battery though.

Wed Jun 27, 2018 10:21 pm

Thanks for everyone's input.

I'm going to do it with just the starter battery for this trip, with the thought the frig is going to turn off when the battery gets low. I also have a lithium jump battery, so I think I'm going to be ok.

I'll let you know how it goes when i get back from my trip on the 19th. :)

Wed Jun 27, 2018 11:25 pm

...and he was never heard from again.

Wed Jun 27, 2018 11:50 pm

Zeitgeist 13 wrote: ...and he was never heard from again.

LOL.

The anxiety of running things off my starter battery would just be unpleasant. It would be nagging in the back of my mind. I would be constantly starting and idling just because. It will be a good learning experience either way.

Thu Jun 28, 2018 7:54 am

Freytag wrote:

I'm going to do it with just the starter battery for this trip, with the thought the frig is going to turn off when the battery gets low. I also have a lithium jump battery, so I think I'm going to be ok.

Your manual should say at what voltage the fridge will turn off. My hunch it's going to be too low for your battery to be of any use, 10v or something. So the jump battery is a good choice. [/quote]

Thu Jun 28, 2018 8:14 am

I would think fridge would have no problem draining battery down to 11v. This is going to hurt the life of your battery - but maybe its covered under warranty.

With a lithium jump pack OP should be fine.

Thu Jun 28, 2018 8:24 am

maybe try it a few days in your driveway 1st.

and you should be fine with having the jump pack..

do what you can to keep the fridge happy and it'll run less.
don't let heat build up in the vehicle,
keep it out of direct sunshine
cover with a towel (but leave the vents open to breath).

Thu Jun 28, 2018 8:46 am

My Dometic CF-40 had a low/med/high cutout and it worked good on medium. The ARB says it has the same thing with cutouts of 10.1, 11.4 or 11.8. The resting voltage is above that when under load, so 11.8 might actually be 12.2 or something. Anyway, it won't drain the battery enough to not start. That is why they have those cutouts in the first place. I would use the higher setting though since it isn't a deep cycle battery.
http://blog.arbusa.com/?p=46

He may find that each day the battery falls further behind. Once, I was driving around Vancouver Island for a week and we were using the stereo at camp for multiple hours every day with the doors open and after 4-5 days the van was getting hard to start. The voltage looked o.k. after running the engine a bit but that was misleading and it wasn't getting charged back up enough between camps.

But obviously it will work if he is watching it. A jump pack is a good backup plan.

Mon Jul 02, 2018 10:28 pm

The ARB battery cutoff works great. I plugged in the 50qt ARB four days ago, set the temp to 23F and set the battery cutoff to medium. I picked up the van earlier today - the frig was turned off, the frig temp was 51F and the van started right up. Pretty darn cool :D

Tue Jul 03, 2018 3:34 am

Freytag wrote: The ARB battery cutoff works great. I plugged in the 50qt ARB four days ago, set the temp to 23F and set the battery cutoff to medium. I picked up the van earlier today - the frig was turned off, the frig temp was 51F and the van started right up. Pretty darn cool :D
No surprise to me. I've borrowed 4WD's with single batteries and D.C. Fridges and camped for a weekend and never started them and been fine.

On a related note, I used the stock Weekender Fridge across the country with a single battery. Just ran it during the day when the van was running, unplugged it at night. Was April, so no real hot weather. So that can be an option for some folks, sometimes.

Tue Jul 03, 2018 9:55 am

AndyBees wrote: Deep cycling a car battery will weaken it's capacity for it's intended purpose. Just go ahead and purchase a deep cycle battery and install or place wherever on a temporary basis! Place something under it if you have to sit it on the carpet.

Andy, what do you think of having a single deep cycle as starting battery (and running fridge, and few LED's)? I'm thinking a jump pack as back-up.

Tue Jul 03, 2018 10:55 am

Optima batteries are not like they once were, but the red top was designed as a cranking and deep cycle battery.

I am using a large Odyssey Battery as a starting battery. It is an AGM battery to match my deep cycle battery that I use when camping. I have a heavy duty battery switch so that they can be combined if needed. Saved my butt last year during Irma.

Conventional starting batteries are cheap enough that I would not sweat killing one before it's time. You might even find it gets prorated if it dies too soon.

Alternator systems were never intended to bring a battery back from a discharged state. They are more suited to maintaining batteries at full charge. You can expect that using the charging system beyond it's design that things will get extra loads which could lead to types of failures.