Adding Batteries / Refer Support

[ThruTraffic]

I’ve got a 2011 Phoenix Cruiser 2551 and am having to replace the refrigerator. The dead one is a Vitrifrigo AC/DC compressor unit that pulls 65w. Two batteries just aren’t enough to support this rig with that type refrigerator. But I really am not interested in moving to AC/LPG.

So I’m considering adding two batteries and using part of the small storage compartment next to the battery compartment. I know the existing fiberglass compartment bottom isn’t strong enough but I can weld/fabricate a rack that would be.

So I’m curious if there are other AC/DC refrigerator owners who have experience in this context.

Any of you run AC/DC refrigerators? How many batteries does your rig have? What are your general thoughts and experience with this?

TIA

[theoldwizard1]

ThruTraffic wrote:
...

• How do you recharging your batteries and how often ?
----- Engine, generator, 400w solar

Trying to charge deeply discharged batteries with the engine alternator will never give you a FULL charge. If this is part of your game plan, get a DC-DC charger.

[CA_Traveler]

time2roll wrote:
12.70 plugged in is just not working. Time to review your charging system.

True unless you have a 5 stage charger like my Magnum where the 4th stage switches to OFF mode and 12.7V after a delay until charging is again needed.

[ThruTraffic]

time2roll wrote:
On shore power the batteries should be about 13.6 volts. Time to review your charging system.

Duh, sorry, forgot to hit the ‘use’ switch yesterday after I parked. ?? Now charge voltage is 13.3. Dumb de dumb de dumb. LOL

[time2roll]

On shore power the batteries should be about 13.6 volts. Solar should bring the battery to 14.2+ during initial charging and about 13.4 volts the rest of the day. Again generator and the on-board charging system should initially raise the battery to 14.2+ volts. This may take an hour or so and then hold that voltage for a couple hours before dropping to 13.6 volts. Need to know the on board charging systems to know exact numbers.

12.70 plugged in is just not working. Time to review your charging system.

[Tom_M1]

The Vitrifrigo looks like it is a decent unit. Have you considered repairing it? I had a pickup camper that had a Norcold AC/DC fridge. It consumed about 3.5 amps on 12 volt when the compressor was running. I had a 100 watt solar panel and 210 amp/hours of battery. I could barely manage on days with full sun. Had to run generator on days that were less than ideal. A residential fridge will be worse.

[ThruTraffic]

time2roll wrote:

We really need to know more about the expected usage. And I assume you turn the fridge off while stored between adventures. Since you mention generator charging it would help to know what the actual charging voltage is and the hours per day spent charging.

Right on on shore power my solar charge controller is showing 12.70v and the inverter monitor is showing 12.7 input as well. In sunlight the solar panels are usually pushing ~18v to the controller; wattage varies, a lot. Hours per day would be a research project given sunlight variations.

Yes, rig not in use, refer not in use.

I use very little juice. The refer is my big consumer. I may run a fan at night, and use my computer a couple of hours a day and a light or two although I'm very frugal with that. I don't watch TV or listen to a radio. Furnace fan is a big consumer in the winter if really cold.

[time2roll]

The reports I read from people with a residential fridge will generally say there is no problem with two batteries even for camping one night without power. Plugged in or in transit is never an issue. For extended off grid 500+ watts solar is good but not enough to avoid using the generator.

We really need to know more about the expected usage. And I assume you turn the fridge off while stored between adventures. Since you mention generator charging it would help to know what the actual charging voltage is and the hours per day spent charging.

You might find some reports by putting "residential" in the search box.

[ThruTraffic]

2oldman wrote:

ThruTraffic wrote:
Compartment floor isn’t strung enough.

2 Li batteries are about 60lb. It won't hold that?

no

[2oldman]

ThruTraffic wrote:
Compartment floor isn’t strung enough.

2 Li batteries are about 60lb. It won't hold that?

[ThruTraffic]

theoldwizard1 wrote:


• How long do you want the refrigerator to run for ?
----- However long it takes to keep it from thawing out and the food spoiling. 🙂
• What type of batteries do you currently have ?
----- The pair that just died:
---------- Interstate SRM-27
---------- https://www.interstatebatteries.com/products/srm-27
---------------- These were in the rig when I bought it used. They appeared to be new and they were working well. They lasted about a year; two months of that road use. The rest of the time the rig was off.
• Are all DC connections clean and tight ?
----- Yes, I maintain the batteries.
• How do you recharging your batteries and how often ?
----- Engine, generator, 400w solar

[ThruTraffic]

2oldman wrote:

ThruTraffic wrote:
I know the existing fiberglass compartment bottom isn’t strong enough but I can weld/fabricate a rack that would be.

Get lighter and better batteries, like Lithium.

If you use a lot of battery you have to recharge. How you do that?

Compartment floor isn’t strung enough. Recharge comes from engine, generator or 400w solar on the roof.

[ThruTraffic]

MrWizard wrote:
You said two batteries, do you mean one engine and one RV battery or do you mean two RV house batteries, Class B, has limited battery space

One engine two RV..

[wa8yxm]

CA Traveler wrote:
Typo wiz??? 6V 220Ah golf card battereries in series are 12V @ 220Ah. It takes 4x 6V batteries in series/parallel for 12V @ 440 Ah.

theoldwizard1 wrote:
If the batteries are getting fully recharged daily, and you have a pair of 6V golf cart batteries (about 440 Ah @12V)

Remember with golf car batteries the usable power is 1/2 the total poer and that's only at the 20 hour rate. faster discharge rates run the battery down faster faster (That's faster ... squared).

MARINE/deep cycle you can only use about 20 percent and again Faster squared.

[MrWizard]

220 ahrs
110 ahrs to 50%

110/6 = 18 hours of run time
50% duty cycle compressor on off = 36 hours battery duration

You said two batteries, do you mean one engine and one RV battery or do you mean two RV house batteries, Class B, has limited battery space
But only one RV house battery offers limited fridge run time approx 8 hours of compressor runtime about 16 hours battery duration to 50% level, batteries should not be allowed to reach the point were the fridge shuts off, that is too much discharge for the average battery ,
A few times like that and the Battery never recovers full capacity and dies a quick death