battery life

[ErnieSeabee]

I have a 2022 forester 4201 MBS. magic chef refrigerator. With everything off, except the refrigerator ( cool setting 2) the cabin batteries only last about 5-6 hours and drop from 13 to 12 Volts.

Any thoughts how to extend the battery life. Dealer said the batteries all check out and no other abnormal sacrificial draws.

Thanks

[TitanMike]

Originally Posted by ErnieSeabee

I have a 2022 forester 4201 MBS. magic chef refrigerator. With everything off, except the refrigerator ( cool setting 2) the cabin batteries only last about 5-6 hours and drop from 13 to 12 Volts.

Any thoughts how to extend the battery life. Dealer said the batteries all check out and no other abnormal sacrificial draws.

Thanks

"Battery Life" will depend on a lot of factors. First will be the size of the batteries (amp hour capacity). Next is the amount of current drawn by appliances, in your case the refrigerator). Also important is the ambient temperature and the number of times the refrigerator is opened.

Since your RV is a new(er) one I'm guessing that the batteries are low capacity items installed by the dealer and really aren't suited to running a 12v refrigerator.

One thing that will help, regardless of battery size/type, will be a battery monitor that uses a shunt to measure current going into and out of the batteries. The OE monitor installed at the factory is usually just a series of LED's that measure only voltage. Does a lousy job of telling one when the batteries are fully charged and don't measure any draw on the batteries.
A shunt type battery monitor, properly set up, will monitor power drawn from the batteries and power replaced during charging. It can also help manage use

It sounds like you have a residential type refrigerator that has a compressor. This type refrigerator draws more power then the old school propane/120vac type. Solution to your problem may well be to add batteries, whether it's more like what you have in parallel, changing to a series/parallel setup using Golf Cart like batteries (6 volt batteries in series), or Lithium batteries that provide more usable power in the same size battery.

[Reverse_snowbird]

All that TitanMike said.....

Can you tell us how you're camping? Are you camping without electric hookup? Do you use your onboard generator when you're camping off grid?
Did it come with a solar panel to recharge the battery?

Lithium Ion would might help, but you have to make certain that you've got protection that it won't burn out the alternator.

[ErnieSeabee]

I'm boondocking or dry camping wiht no utilities. Charging the batteries wiht the onboard generator. no solar panels. I can't tell the rating from the manufacturer of the battery amp hour rating

[NMWildcat]

How long are you running the generator to recharge? When boondocking I run mine at least 5 hours a day.

[Reverse_snowbird]

You didn't say what kind of refrigerator you have.
Unfortunately, you seem to be getting the same results that others have reported with a refrigerator tied to an inverter. As NMWildcat says, it takes hours to charge the batteries and the batteries are running other things in the rig at the same time, so that decreases the charge to the batteries.

Your options may be to buy a portable solar 'suitcase' panel and plug it directly into the battery. Or drive your rig somewhere. Our engine recharges the batteries faster than if we're 'plugged in'. Of course, the battery must be connected via the battery disconnect switch.

[bikendan]

The OP probably has a 12v only fridge so no inverter involved.

[Aussieguy]

if you are NOT going to use the a/c or other high amp 120v I would get one of the small around 2000 , 2200 Inverter generators to charge up your batteries and run fridge / fans etc



no need to add a lot of hours to the bigger coach generator + can move the NOISE out of the coach

[tomkatb]

You are flying while blind!

Battery voltage is 0-12.6. Any reading above 12.6 indicates a bad voltmeter, something is charging or poor practice. Batteries have a residual charge after being charged. For 1-2 hours. Never should be see below 12.0 volts, 50%

It takes overnight to charge a low battery with a converter.

You need to properly load the fridge.

Over night charging before a trip. The more full It is the longer it lasts. You should add gallons of frozen drinking water, adds to how long it cools.

You need to examine the battery system. You need the size of the battery.

My guess is that your dealer installed the DOT required emergency brake battery. Never intended to operate the fridge. Much to learn.

Your fridge on a hot day likely requires nearly 10 amps dc per hour to run.

Likely your battery is only good for 40. The math is simple. 4-8 hours of operation on a day depending on weather.

Compressor fridges from the dealers seldom can work overnight in warm weather. It’s the math.

You likely need a huge battery. Or plug in every day.

[Reverse_snowbird]

tomkatb,

ErnieSeabee, the original poster has a Class C MOTORHOME. A battery only for brakes doesn't apply. A battery reading of 13+ is normal for his mh. The battery will charge as the motorhome is driven if the 'house' battery is connected as well as charging from the onboard generator.

However, I agree that his refrigerator probably isn't going to last all night and the suggestions for loading the fridge and adding frozen water are good ones. We have a friend who was having trouble keeping his 2way fridge cool and a bag of ice in the freezer and fridge help keep it cool.

With his setup, the best way to keep the mh powered off grid is probably his onboard generator. Most places will allow you to run it til 10pm. and that should help keep it cold til the morning.

[ErnieSeabee]

Thank you