Battery/12v Fridge Help!

Sounds to me like;
A. ether the battery won't carry a load (Battery Load Test)
B. Battery is no longer charging up fully (voltage check after running a sufficient period of time)
C. The fridge's circuit is drawing allot more than it used to. (Measure the fridge's current/watt draw or run longer duration tests with a power bank).

 

Load test at O’Rileys came back that both batteries are outputting over what they’re rated at (Rated: 860CCA, Output: 880+), so according to what they said, both batteries are good.
I’ll pick up the power bank tonight & run some tests on the fridge, & also take out the Genesis system & hook up just a single battery to see if that changes anything. The voltage reading in the cab still shows 12.6v though after sitting for just a few minutes.

 

That eliminates the most probable culprit. Testing the fridge off a power bank may not show your problem. It's only testing the fridge and it's cord. If there's a poor connection or other issue with the truck it won't show up with that test. If you can't detect that it's using more power when running from a power bank I'd go back to the clamp-on amp meter, measure the current out of your aux battery with only the fridge running (when it's cycling) and compare it to measuring the fridge's current at it's DC power cord when running off something else like the power bank. If there's a difference it's going to be that the test at the battery is higher current. That difference, if there is one could be your issue, it's power consumed by the wiring to the fridge (the truck). I would expect to see very little difference in those 2 measurements.

 

Is your fridge tripping off due to low voltage?? If you are powering the fridge via a cigarette light type plug, I'd start right there. I swapped mine out with Scotty down rigger plug and fixed all of my operational voltage weirdness.

$31 Scotty #1125 Depthpower Hella Electric Plug and Socket Black, Small

https://www.amazon.com/Scotty-1125-...54&sprefix=scotty+down+rigger+,aps,255&sr=8-4

 

We’ve never had the fridge actually kick off, but I’m constantly playing battery watcher throughout the day. Just doesn’t seem like it would/should drop a battery to under 12.2v in roughly half a day - that’s what I am trying to avoid so I am not damaging them with under voltage cycles.

 

If you want to avoid damage, have you set your Fridge's shutoff voltage? There is usually 3 settings. When the fridge reads a certain low voltage, the fridge shuts off instead of killing your starting batteries. Dometic does it, and I thought ARB did too.

This obviously isn't solving your issue, just might set your mind at ease.

Looks like ARB and Dometic match for these settings now. This is for the ARB Zero, which i think you said you had. Also looks like HIGH still shuts off pretty late... dang... i'm surprised it's that low of voltage, lol.

 

Ours does include the battery shutoff - I have ours set to the “medium” protection.

Seems like I get conflicting info when trying to to figure out how low I should be letting voltage on these batteries get… Generally if it get to 12.2 or 12.1 I’ll go ahead & start it up.
Medium protection from ARB is all the way down to 11.4 before it auto shutoffs.

 

My experience was the first time I ran my Dometic fridge off my starter battery overnight I killed my starter battery. Your lead-acid battery isn't the best solution to run your fridge off of. A lithium as a second or "house" battery is better for that. I bought an EcoFlow power station. Then I got a 100w solar panel. Since I kept the fridge in the cab I ran an outlet off the OEM inverter in the cab. So the fridge ran off the EcoFlow and the EcoFlow was fed by the inverter (having to remember to turn on the inverter was a hassle) and the solar panel. That worked out.

Remember lithium batteries you can run almost dead without damaging them. Lead-acid if you run them below 50% you are risking damage. I'm guessing you've discharged your lead-acids too low and they now have a shortened life.

Now I've added a wedge camper and building that out with 200AH of LifePo, 200W of solar, and a 2,000w inverter.

 

Do you have a voltage booster installed?

It may be that after a couple years the charge voltage hasn’t been optimal for your AGMs and now they are showing the wear.

Im assuming the alternator cable and all that was upgraded with the DC power alternator as well?

To my understanding the older Genesis systems ran just a generic mechanical relay battery isolator, newer systems run what’s effectively a Littelfuse version of the BlueSea battery isolator. These systems aren’t super optimized for dual battery health either. I mean I run the blue sea stuff but the dc-dc chargers out nowadays tend to perform better.

 

Thanks for this suggestion. I've been using my original cord that came with a truckfridge tf51 i bought 4+ years ago. I cut off the cigarette outlet side and put an anderson power pole connector that i connect to the truck. I've been having issues for multiple camping trips now that my voltmeter next to the fridge (connected to the same blue sea fuse box but different circuit) shows 12.2+ v but the fridge was reading 10.8v and close to cutting off. The power circuit looks fine (tested with voltmeter and visually inspected the run). gonna try a new cable next trip. a regular cigarette power cable works but I don't have a spare cable with an anderson connector on it.

 

I’m curious if maybe I just need to swap out the accessory battery w/ another Group 34, but a Lithium instead.
The Odyssey batteries claim they can do 400-cycles @ 80% depth of discharge, which I know for a fact I’ve only come close to that possibly once - I am usually pretty hyper focused on keeping their voltage up.

 

I'd explore why that voltage is different on the fridge circuit compared to the other circuits. A simple (fridge connected) vs (fridge disconnected) voltage measurement on the fridge circuit might be telling. If there's another circuit fed from the same source (battery) it should display a similar voltage reading. I could think of a few reasons that might happen; a poor connection in the fridge circuit, bad cord or internal problem in the fridge. If it was a battery issue then I'd expect both circuits to be affected similarly when the bad battery was hit with the fridges load.

 

How long have you had your batteries? Had an AGM Odyssey battery in my 3rd gen for ~3 years and it was no longer able to run my fridge. Turns out the stock alternator doesn't put out enough juice to fully charge AGM batteries. For 2nd gens, youre going to need to install a voltage booster:
https://www.tacomaworld.com/threads/agm-battery-charging-alternator-voltage-booster.611314/
https://www.tacomaworld.com/threads/the-northstar-agm-battery-voltage-booster-upgrade.604478/

 

Chiming in here about lithium. Ive had my setup for about 3 years, and no issues. I have dual inputs solar (200w) and alternator. I have an Iceco VL60ProS fridge thats newer, but about the same age as the dual battery setup.

I wanted to say that you don't necessarily have to get the best lithium, if you are going that route. When i bought mine, there were more expensive options.

Ill bow out now, since im not as knowledgeable in this subject.

 

You can't just swap an AGM for a Lithium. They have different charging profiles. You'd be better off putting the Lithium elsewhere, and using a DC-DC charger to charge the Lithium.

 

IMHO I dont trust their (or any handheld) "battery testers" any further than I can throw them. I brought my truck there to buy a new battery after having to jump it 3x that day. I knew it was cooked, but the rep insisted on "testing" it before selling me a new battery. I gave in and let him do his thing.

My old battery passed with flying colors, despite not holding a charge to cold start after more than a few hours. I bought/installed a new battery and haven't had any issues since.

If you want a useful test, you gotta get a real load tester (one of the big bastards) that actually loads the battery, and doesn't just "simulate" a load to extrapolate an imaginary measurement.

 

Way to many potential culprits in this problem to just fire off a solution. Suspect it's a combination of several factors making a absolute solution difficult.
Not much help I know.

 

watching this thread - i was intending on getting the same exact thing from genesis offroad one day since i was tired of constantly running my 12v dometic off the stock lead-acid in our 2015 taco. i thought the genesis offroad setup would completely solve the issue and let me run the fridge constantly for days at a time, but i guess that's (potentially) not the case?

 

I avoided this whole thing by going the power cube route. Then you only use the truck for truck things. They have been around long enough now that you can find 500watt or up to 1000watt storage for 150.00 on marketplace. Get a solar panel to charge it and you are off.

We actually have two now. One 500 watt and one 750watt. It's mobility and fast uptake 400watts means you can literally plug it in getting gas and 1 hr later it's 80% full. If you leave with them fully charged and set up solar panels, you will return from a camping trip at near 100% power, and we camp in the hot desert for a week at a time with Popsicles. I recommend having two smaller capacity rather than one larger. They do heat up after prolonged use depending on ambient heat they will shut down for a cooling cycle. Hence my discovery of two smaller units not one larger.

Its truly the simple way to go. They are amazing.

Edit: look at this. I love this brand... 350 bucks... absolutely solves every power wish or want you could ever need.

 

we just finished a camping trip a few weeks ago, and i had intended to run the fridge off my battery and solar panel during the day. backyard tests proved it worked fine w/o any problems, and the battery essentially stayed at 100% all day.

the thing i wasn't expecting was our site had a ton of trees, and the clouds were relentless that weekend. chasing small patches of sun (if even even available) every 10-15 min SUUUUCCCKKKEEEDDDD.

times like that i wish i could just leave the fridge plugged into an aux battery in the taco.