Coach battery replacement suggestions

[vanderwerff]

Anyone have good advise on coach battery replacements? Would like them to last at a minimum of 10 hours if possible without recharging.

[babock]

Can't answer your questions unless you can tell us what load is on your batteries for the 10 hours.

[vanderwerff]

Full size Frigidaire

[vanderwerff]

[babock]

Originally Posted by vanderwerff

Attachment 170446

That is not enough info since it isn't on 100% of the time. Also, what else is consuming power and how much.

You need to do a complete energy audit to come up with what battery capacity you need.

[McCormickJim]

following

[vanderwerff]

I just want the fridge to be powered only. if we are out in desert riding. I Would like fridge to last over night... or while we are not at camp.

[babock]

Originally Posted by vanderwerff

I just want the fridge to be powered only. if we are out in desert riding. I Would like fridge to last over night... or while we are not at camp.

Plug in the camper to a kill-o-watt meter and see how much it uses. You can do this in your driveway. Until you know how much power it uses over a 24hr period, you will be guessing on how much battery you need.

[Flybob]

To do this correctly, you need to measure the power used during a 24hr period as mentioned. Just as a rough example if the fridge runs 25% of the time it would require 340AHR worth of battery to run the fridge for 8hrs. This is a rough number and assumes nothing else is running on the battery. To avoid a costly mistake, suggest you do some measurements prior to making a decision.

[garbonz]

Making a couple of assumptions and a SWAG, using a 1000 watt inverter, when that baby is running it will pull about 80 amps of 12 volts. At even a 25 % duty cycle that would be 200 amphours and maybe 300 plus at a 40% duty cycle. So, just the frig alone would need between 400 and 600 amp-hours at a 50% SOC if you manage to full charge during the day.

Maybe someone here has one of these frigs or similar and will actually know.

[babock]

Originally Posted by garbonz

Maybe someone here has one of these frigs or similar and will actually know.

It will take someone who has the exact same fridge and someone who camps in the exact climate. Since the OP is in southern California and he is camping in the desert it could be really high.

[tomkatb]

According to the label you need1000 watts to run it an hour. Four 6 volt batteries would give you 3 hours continuous. 230 amps.

This is not a very efficient fridge. I thought typical was 20% of that. 150-200. Four batteries might do that.

[Tom48]

That's the reason that DW won't even let us look at a coach unless it has a gas refrigerator. We spend most of our time off hook ups. Start with the assumption that you probably can't carry enough batteries to run that house for 24 hours. Then after you determine your usage needs get some estimates as to how much of that usage can be replaced by solar. We just run two golf cart batteries without a residential fridge, have the whole house on a 2000 Watt pure sine inverter that runs part time as needed, and with 380 watts of solar, our batteries are virtually always charged.

Pretty sure off-grid living with a res frig is going to take some combination of a large battery bank and continuous replenishment such as say 400 to 500 watts of solar on your roof. If you have the skills to do it yourself that's not a really expensive project. Look at WindyNation.com

[wrapperman]

Originally Posted by vanderwerff

Anyone have good advise on coach battery replacements? Would like them to last at a minimum of 10 hours if possible without recharging.

We have a 2013 378 XL with the same fridge. I replace my stock batteries with 2 Trojans T1275. I wanted to see how long mine would last and I got over 12 hours without shore power. During the run time the battery voltage never dipped below 12.01 volts. I then disconnected the batteries, waited 2 hours then tested the batteries. They were still 12.2 volts. If you used 4 12 volt batteries or 4 6 volt batteries you will be fine. Outside ambient temps were 85 degrees. Limit opening the fridge doors during that time.
Just last month I parked my rig and forgot to connect to shore power and the fridge was still running 24 hours later but it was a cool day.
I paid 159.00 a piece for the batteries.
This is from personal experience.

[vanderwerff]

Thanks

[wrapperman]

Originally Posted by vanderwerff

Thanks

If unsure buy a couples of solar cells. You will then be fine for sure.
Happy camping.

[jimmoore13]

This is an excellent calculator.
https://www.rapidtables.com/calc/ele...alculator.html
Always use 12 volts, because that's what the batteries deliver.
If your fridge draws 500 watts on a 50% duty cycle (hot summer day), the calculator shows a 41 amp draw...at 50% duty cycle, that's 20 amp-hours per hour on average....over 10 hours, that's 200 amp-hours.

That kind of draw suggests a 4 x 6-volt golf cart batteries bank. Their capacity will be a bit over 400 amp hours, but a crude rule of thumb on battery use is that you confine use to about 1/2 the capacity. Thus, the 4x6-volt batteries bank will safely deliver a bit more than 200 amp-hours.

Since daytime is your concern, add solar. Problem solved.
This kit is simple and relatively cheap. You can have 4 x 100 watt panels feeding through a single charge controller straight to your battery bank. No conflicts with the "house power" and "shore power" through the RV's converter. Seamless and easy. This setup will deliver about 30 amps of charge in sunny weather....giving you a net gain of 10 amps/hour with just the fridge running. In other words, with your 4-batteries bank and the solar, you'll go to bed at night fully charged.

https://smile.amazon.com/WindyNation...olar+panel+kit

Renology is another excellent brand.
I use a single panel system on my single group 24 12-volt battery, and I never run out of power. Of course, I'm running a small, 3-way fridge on propane, but before bed, I run a 360 watt electric blanket through an inverter for 30 minutes to take the chill of the bed in our PUP. That's 15 amp hours all by itself. My battery starts off with a USABLE capacity of about 35 to 40 amp hours. My furnace draws 5 amps on about a 50% duty cycle on a cold night. Then there's the pump, lights, hot water heater ignition, and so on. My puny 12 volt battery has just enough to get to the next day's sunshine safely, and then it gets fully recharged by late afternoon. (Colorado is reliably sunny.)

My panel is mounted flat on the roof...painless and secure. They say a bit of dirt on the panel affects power very little.

There are rigs that have 3 pairs of 6-volt golf cart batteries, but, with solar, it's unlikely you'd ever need a bigger battery bank unless you are a profligate power hog after dark.

[jimmoore13]

Originally Posted by vanderwerff

Attachment 170446

You need more info on this fridge. I suspect the 8.5 amps draw at 120 volts - that's 85 amps at 12 volts - is peak draw at startup. That actually exceeds the continuous capacity of a 1000 watt inverter!

Most appliances have a starting amperage draw and a much lower running amperage draw. It would be worth it to dig out the owner's manual and see if Electrolux provides this info.

As others have said, 85 amps will drain a massive 4 x 6-volts batteries bank in 2 1/2 hours. That just doesn't make sense. You'll be chained to shore power or a generator with that kind of draw.

[FFred]

You can help the fridge stay cold by using frozen pocket packs, in the freezer.

If you have a lazer thermometer you can get a plastic water carry bag that will fit into the freezer compartment ,,fill it with water and a pound or two of salt.

Freeze it solid and find the temperature it is melting at with the thermometer, and measure the temp of the food section below.

Colder food will require more salt in the home made eutetic plate.

Its cheaper and easier to save cold,rather than electric for limited use.

Have fun , it works!

Tho for real extended boondocking a propane reefer is the only solution.

[ScottBrownstein]

Sorry I missed this before. I have a lot of experience with this specific model and since, other modern energy star models. Not your father's frig! Most are inverter powered and go through a complex cycle with a variety of power consumptions. Max draw on this unit is around 48 amps, but only for 15 minutes or so every 7 or 8 hours. Then it drops down to 12 or 13 amps for an hour and then idles down at around 5 amps for 6 or more hours. It has a variable speed compressor. Average draw is about 8 amps or 100 watts at a 100% duty factor. Ambient temperature matters, but not that much since Energy Star ratings must be done at 90 degrees ambient.

With 2 good deep cycle batteries at least 12 hours, with 4, 24 hours....