Quick options for my fridge power

Mtpisgah

Active member
I am running a Genesis dual battery setup, no issues for four months. This week I added a Dometic CFX3 45 to it. It ran great from 7pm last night until around 6pm tonight and then it killed the battery. The truck still started with no issue, but no fridge. I had the fridge set to low battery protection which could be part of the issue, but I am not sure medium would have helped in the long term (A couple of days parked).

I leave for a 14 day vacation on Friday so my time to figure something out is very short. if I had more time, I would throw a solar system on the truck, but the parts are not in stock locally and no time to order and install.

I am thinking my options are a PLB40, Goal Zero or similar. Charge both batteries while I drive and then the fridge is powered from the second Genesis battery and portable battery over night and while parked during the day. Does this sound reasonable? Is there another option for the short term? can I have the Dometic plugged into the truck and PLB at the same time? i have the Dometic hardwire kit and the fridge is plugged into it. Would the PLB plug into the other outlet? Would a Goal Zero?
 

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Mtpisgah

Active member
You faile to mention what type, size and age it is.
But sounds like your house battery is duff. Have you load tested it ?
I will have to check tomorrow on brand, but it is a group 25 dual battery system. They are about six months old. I have not had it tested but will try to do that tomorrow. What does ‘duff’ mean?

if it is the battery then I could replace it for less than a PLB would cost, but would a new battery solve my issue?
 

jonyjoe101

Adventurer
you need a larger battery, at least one that is deep cycle. Something in the 100ah range. A 12 volt fridge set to 40 degrees comsumes about 20ah per 24 hours, a 100ah lead acid will run it for about 2 days before you have to charge it again. You need to make sure the battery isnt drained below 12.1 volts (50 percent).
If your group 25 batteries have gone below 11 volts, you need to fully charge them back up, start batteries won't handle being discharge that low too many times.
The problem with the goal zeros is they charge too slowly, you would need to have a way to charge them every day.
The alternator will quickly charge your lead acid to about 80 percent but then the batteries start taking less amps as they get closer to 14.4 volts. You would have to drive alot to fully charge with the alternator. Maybe your current batterys havent been reaching a full charge everyday. Next time you get a chance measure the voltage at the battery terminals while the alternator is running, it should be exactly 14.4 volts. I seen some alternators that don't produce 14.4 volts all the time only during startup and as accessory demand more power.
As far as solar, you don't need a large system, I use to run an edgestar 43L 12 volt fridge with just a 75ah agm and a 120 watt solar panel. Never needed the alternator. But you have to have good sun.
 

Mtpisgah

Active member
you need a larger battery, at least one that is deep cycle. Something in the 100ah range. A 12 volt fridge set to 40 degrees comsumes about 20ah per 24 hours, a 100ah lead acid will run it for about 2 days before you have to charge it again. You need to make sure the battery isnt drained below 12.1 volts (50 percent).
If your group 25 batteries have gone below 11 volts, you need to fully charge them back up, start batteries won't handle being discharge that low too many times.
The problem with the goal zeros is they charge too slowly, you would need to have a way to charge them every day.
The alternator will quickly charge your lead acid to about 80 percent but then the batteries start taking less amps as they get closer to 14.4 volts. You would have to drive alot to fully charge with the alternator. Maybe your current batterys havent been reaching a full charge everyday. Next time you get a chance measure the voltage at the battery terminals while the alternator is running, it should be exactly 14.4 volts. I seen some alternators that don't produce 14.4 volts all the time only during startup and as accessory demand more power.
As far as solar, you don't need a large system, I use to run an edgestar 43L 12 volt fridge with just a 75ah agm and a 120 watt solar panel. Never needed the alternator. But you have to have good sun.
Thanks for the detailed response. I have read of people running their fridges from PLB40s for two days and they only have 40ah. Is it the difference in the batteries between the PLB and a lead acid for the run times? Unless there is an easy way to hook up a lead acid to the Dometic, I really do not have time to build a system from scratch.

I will need to check the secondary battery with a volt meter later today. The dashboard meter tells me the main battery is at 14.2 when driving to work this morning which I know has no relation to the secondary. This is in a 2021 Jeep Gladiator, not sure how great the alternator is.

I drive 15 miles each way to work, I am not sure if that is enough for a full charge. Secondary battery power has never been an issue, but I just installed the fridge on Tuesday so it never drew much power before that. I will have the batteries tested today at Batteries Plus (just around the corner from my office) and see what they say.

Solar will be in my future I guess. Between the Genesis dual battery, a PLB/GoalZero/Jackery, and a solar package I will be ok. I just need to figure out something quick and easy for this trip. And yes, I wish we had decided to buy the fridge two months ago and not two weeks ago so I could have this sorted already.
 

jadmt

ignore button user
too late to get by friday but maybe something to think about in the future. unless you live in Fremont, Ca.

 

coastalcop

Active member
with your Friday deadline lithium jumppac find one a local auto supply , costco, walmart maybe. Plug into lighter while driving so its always 100%. Run the battery down on the trip, use the jump pac.


Solar when you have more time ! Enjoy the trip either way!
 

plh

Explorer
AGM and lead acid batteries don't last long taking below 50% state of charge before recharging is the issue. So a 100Ah rated AGM really should be babied to use only 50 of those Amp Hours before getting a good charge into it. I'm guessing over an averaged day your fridge will use 24 of those (about 1 amp per hour averaged over the day).
 

Mtpisgah

Active member
too late to get by friday but maybe something to think about in the future. unless you live in Fremont, Ca.

I saw that, it is tempting. Maybe I will order and have it waiting for me when I get home.
 

Mtpisgah

Active member
Yes. A lithium battery of a given capacity, 40Ah for example. Holds more usable capacity over its 40Ah lead acid colleague. At this point you might have to hook up the largest lead acid you can fit then baby that along until you get a better system sorted.
Fwiw,
Lately I been using my Alpicool ’fridge with the Hilux running off its 7 year old group 24 starting battery. Temperatures in 80°s, its been working fine driving 3 hours each day.
I not bothered tracking voltages or anything, But next day, my truck is noticibly sluggish starting and I would not be doing this if I had no means of getting jumpstarted.
I have the battery on a tender for the night to make sure it is fully charged tomorrow. I have a six hour drive tomorrow and that should keep it charged too. I turned the battery protection to high for now and will try it at medium during the trip. Hopefully this will cure the issue and be similar to you running your fridge.

Solar system will be ordered before we get home though.
 

Mtpisgah

Active member
with your Friday deadline lithium jumppac find one a local auto supply , costco, walmart maybe. Plug into lighter while driving so its always 100%. Run the battery down on the trip, use the jump pac.


Solar when you have more time ! Enjoy the trip either way!
I may pick one up either one the way out of town or when we get to Taos if it is still giving us issues with the change in the battery protection level. Solar to be ordered soon.

Thanks, we are looking forward to the trip
 

Mtpisgah

Active member
AGM and lead acid batteries don't last long taking below 50% state of charge before recharging is the issue. So a 100Ah rated AGM really should be babied to use only 50 of those Amp Hours before getting a good charge into it. I'm guessing over an averaged day your fridge will use 24 of those (about 1 amp per hour averaged over the day).
I think my batteries have 68ah based on my recollection. I will pay attention to the time it runs. With more driving I think it will be good.
 
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67cj5

Man On a Mission
Thanks for the detailed response. I have read of people running their fridges from PLB40s for two days and they only have 40ah. Is it the difference in the batteries between the PLB and a lead acid for the run times? Unless there is an easy way to hook up a lead acid to the Dometic, I really do not have time to build a system from scratch.

I will need to check the secondary battery with a volt meter later today. The dashboard meter tells me the main battery is at 14.2 when driving to work this morning which I know has no relation to the secondary. This is in a 2021 Jeep Gladiator, not sure how great the alternator is.

I drive 15 miles each way to work, I am not sure if that is enough for a full charge. Secondary battery power has never been an issue, but I just installed the fridge on Tuesday so it never drew much power before that. I will have the batteries tested today at Batteries Plus (just around the corner from my office) and see what they say.

Solar will be in my future I guess. Between the Genesis dual battery, a PLB/GoalZero/Jackery, and a solar package I will be ok. I just need to figure out something quick and easy for this trip. And yes, I wish we had decided to buy the fridge two months ago and not two weeks ago so I could have this sorted already.
I own a few fridges and I power them all with PLB-40's, The beauty of the PLB's is that they come with a Ciger lead with the big 50Ah Anderson plug on the other end and the PLB will charge quickly from a 12v Cigar socket, I use this setup all the time and while driving I feed the PLB with the Cigar/Anderson lead and when parked I unplug the lead from the Ciger socket because all my 12v Sockets came Live from the ford Factory then My fridge's are running direct from the PLB and when I start the Vehicle I plug the PLB lead back in to the Cigar socket and it fully charges the PLB within 1 to 2 hours, This setup works that well that I just don't have a need for a duel battery system or DC to DC chargers,

The reality is if you are on the move a lot then the PLB only has to power a fridge for around 12 hours whilst parked, and when the fridge is set to around 2*c or -10*c the PLB has more than enough to power my big ARB 78L / 82Qt fridge., I own 2 PLB-40's and One PLB works better than an 80Ah AGM plus they charge a lot faster and even when flat they can charge in around 4 hours +/- and if the PLB has only powered the fridge over night then it can be fully charged in under an hour when used/Charged this way.

Hope that helps, but the PLB is really the best way to power , charge for a person or family on the move.

J.
 
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Mtpisgah

Active member
Well I put a battery tender on the truck overnight to no avail. I disconnected the secondary battery from the main this morning and continued charging. When I took it off a few hours later it was to almost 100%.

We then hit the road and plugged the fridge in. No dice, still not working. I stopped at rei and bought a Goal Zero 500 (could not find a PLB in stock) to get me through this trip. Tomorrow I will probably stop at an auto parts store and buy a new secondary battery if this one does not come to life. Maybe I discharged it too much? The guy at Batteries Plus said it was good yesterday, just low.
 

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