what runs on battery without inverter?

[Lornanaugle]

So confused about inverters


Anybody know how long the refrig would last if it was just on battery?
I know that I could put it on gas.

Nancy

Regarding the refrigerator: My first time out in the trailer in sunny San Diego, I thought, ok, I can run the fridge on the battery--we have solar and an inverter. Not so! I drained the battery in a day!

I learned and now I know!

Lorna

 

[tdf-texas]

Regarding the refrigerator: My first time out in the trailer in sunny San Diego, I thought, ok, I can run the fridge on the battery--we have solar and an inverter. Not so! I drained the battery in a day!

I learned and now I know!

Lorna

Even running the fridge on 12v connected to the tow vehicle is a loosing battle. The fridge pulls a lot of amps! Escape now modifies the control board on the fridge so that it doesn't auto switch to 12v - you have to manually switch it. Too many people had bad experiences with the auto switch.

 

[The Quilting Lady]

Is it difficult to get to the double 6 V battery in and out? My husband would take the battery into the house and leave it in the laundry room during the winter and it would start up just fine after that.do we have to have an outside latch for that or can we get it in and out through the inside bench?

 

[Jim Bennett]

Is it difficult to get to the double 6 V battery in and out? My husband would take the battery into the house and leave it in the laundry room during the winter and it would start up just fine after that.do we have to have an outside latch for that or can we get it in and out through the inside bench?

No need to take the batteries out, they should just be kept at full charge. I have always left batteries in over the winter, and never had a problem. If they are discharged though, they will freeze.

 

[ReagentGrade]

Nancy,

In my experience, the biggest 12V power hog is the furnace. Although the heat comes from propane, the fan must run. That fan takes more power than any other 12V device. If you plan to boondocking in cold weather, that could be a concern. Solar would solve that. I don't think the ceiling vent fan does not use as per as the furnace fan.

The fridge, when cooling on 12V, also takes a lot of power. I always run mine on propane so I don't have personal experience with that. When on propane, the fridge still uses 12V for the control circuits, but that's pretty minor power draw.

I second the motion about solar. The panels used for RV are pretty sturdy. Glass covered panels would not be a good thing for an RV.

Rich

 

[CoolCampingKid]

Ms.Quilting, I have a small hatch on my 5th wheel (don't shoot me it is a stick build for now) where I can plug in my portable solar panel cord in . You may want to talk to Tammy about that ... On an important note, the longer the cord to the portable panel the more "voltage drop" you will get so keep it a reasonable length. Also with a portable panel you will need a charge controller so it does not over charge your batteries. My charge controller is in my camper. Keep in mind that solar is not needed if you are plugged in or plan to mostly camp with full hook-ups. Keep asking questions until you feel comfortable about this information. Electricity can be confusing but when you are self contained all your resources need to be managed carefully to improve the camping experience! Have fun out there campers!

 

[rubicon327]

Regarding the refrigerator: My first time out in the trailer in sunny San Diego, I thought, ok, I can run the fridge on the battery--we have solar and an inverter. Not so! I drained the battery in a day!

Just to avoid confusion for those that are learning about their electrical systems, the inverter would never come into play with the refrigerator. The inverter is only wired to outlets. The fridge when on 12V (if you have a model that is capable) is fed directly from the battery.

 

[The Quilting Lady]

Even running the fridge on 12v connected to the tow vehicle is a loosing battle. The fridge pulls a lot of amps! Escape now modifies the control board on the fridge so that it doesn't auto switch to 12v - you have to manually switch it. Too many people had bad experiences with the auto switch.

I was hoping I could leave the refrig on battery for one night in case I had to check in to a hotel for some reason..... do you think it would still drain a double 6v?

 

[Karen H.]

I was hoping I could leave the refrig on battery for one night in case I had to check in to a hotel for some reason..... do you think it would still drain a double 6v?

Absolutely no reason to run it off the battery in this event...keep it on propane.

 

[Rossue2]

Will absolutely drain your batteries and sound an alarm on fridge. Don't ask me how I know this happened in the middle of the night

 

[The Quilting Lady]

Oh, ok Karen and Rossue, Thanks for the info. So only run on battery when you are going down the road. So if I stop to go into an restaurant for an hour what is the best thing to do?

 

[Dave Walter]

Oh, ok Karen and Rossue, Thanks for the info. So only run on battery when you are going down the road. So if I stop to go into an restaurant for an hour what is the best thing to do?

There is no reason to ever run the fridge on batteries. Just leave it on propane at all times (driving, stopping, camping, etc). No worries.

 

[rubicon327]

If the fridge on 12V is 350W as Alan said in post #20 then it is not really useful at all in my mind. I think many falsely believe that is the mode they will use when towing (because no 120V obviously and some may prefer propane off while underway). Solar and/or tow vehicle would be charging battery....but sounds like not fast enough. Can someone justify the need for the 12V DC mode at all? Do you actually use it successfully? I'm only familiar with the older 5CF Dometic that is propane and 120V AC and this has always worked great.

 

[Karen H.]

Oh, ok Karen and Rossue, Thanks for the info. So only run on battery when you are going down the road. So if I stop to go into an restaurant for an hour what is the best thing to do?

There are many threads on this subject but here's the bottom line. Before leaving for a camping trip, plug the trailer into the house power to cool the refer--do this the day before. Put only cold food in the refer to maintain low temps. When underway, run the refer on propane. Or if you're averse to that for whatever reason (or on a ferry) you can run the refer off the battery but it does pull a lot of power; whether that loss is made up by solar input or tow input is dependent on a number of factors. The other option is not to run the refer at all when underway. Several people have cited that the refer will stay cold for several hours while underway. Again, this would depend on several factors including ambient temps.

In three years, I have never run the refer off the batteries. It's either on propane or, if I'm at a powered site, it's on 120v.

 

[gbaglo]

And, don't open the fridge door if you can help it.
We place cheeses, sandwich meats and butter in a container that can be quickly removed from the fridge so that the door isn't held open while you root around.

 

[cpaharley2008]

Cannot emphasize solar and dual 6 volts will keep you charged and short times on battery will not hurt. When traveling I leave it on propane except when hooked to electric, then I manually switch over.

 

[rubicon327]

If the fridge on 12V is 350W as Alan said in post #20 then it is not really useful at all in my mind. I think many falsely believe that is the mode they will use when towing (because no 120V obviously and some may prefer propane off while underway). Solar and/or tow vehicle would be charging battery....but sounds like not fast enough.

Just out of curiosity I looked up the 12V specs on the RMD8555 which seems to be a popular fridge. It draws 130W, so that is ~11 amps at 12V. So on paper with perfectly charged dual 6V batteries with 232 amp-hrs you would be drained in about 21 hours. In reality this would be much less because the battery is used by other things, batteries aren't perfectly charged and available amp-hrs are likely less than 232 depending on the rate battery is drained. Anyway this was just an exercise to get a ballpark on how long dual 6V batteries may last with fridge on 12V. Obviously you would have some coincident charging typically from tow vehicle or solar but the question is how much. I saw a post from John David from 8/2016 that said he did great with his fridge on 12V but he also had 320W of solar. That is double what ETI currently installs with their standard solar option.

 

[vermilye]

Just out of curiosity I looked up the 12V specs on the RMD8555 which seems to be a popular fridge. It draws 130W, so that is ~11 amps at 12V. So on paper with perfectly charged dual 6V batteries with 232 amp-hrs you would be drained in about 21 hours. In reality this would be much less because the battery is used by other things, batteries aren't perfectly charged and available amp-hrs are likely less than 232 depending on the rate battery is drained. Anyway this was just an exercise to get a ballpark on how long dual 6V batteries may last with fridge on 12V. Obviously you would have some coincident charging typically from tow vehicle or solar but the question is how much. I saw a post from John David from 8/2016 that said he did great with his fridge on 12V but he also had 320W of solar. That is double what ETI currently installs with their standard solar option.

While this is, as you stated, an exercise, I'd like to add a couple of points to make it a bit more realistic:

First, to avoid damage to your batteries, they should not be drawn down to less than 1/2 of their capacity, so that takes us down to 10.5 hours.

As to recharging, while the 320 watts of solar might keep the batteries charged while running the refrigerator under ideal conditions, real world results will be a bit less. For example, I have 195 watts of solar on the roof & a 160 watt portable panel. On paper, the 355 watts of solar should give me almost 30 amps of charging current. Real world, I've never seen better than 20 amps of charging current from the combination.

Right now, with the portable panel aimed at where the sun would be if it wasn't for the clouds and light rain, combined with the roof top panels, my current charge rate is 1.1 amps with the solar controller in the bulk mode. Under clear skies I would be getting 15+ amps in the middle of a winter day, better during the summer, but with real weather, low angle winter sun, etc it is what it is. A couple of days like this in a row will leave you wanting.

Even with a pair of 6V batteries, I wouldn't count on being able to run the refrigerator on 12V for any serious length of time. If you must, I'd be more comfortable with doubling the battery capacity, and adding more solar or plan on using a generator to recharge the batteries. Propane makes far more sense for most users.

 

[rubicon327]

John, great info. Thanks. Do you really need to cut my initial 21 hours in half? The "20hr" test that mfr's use to determine amp-hrs is supposed to ensure that amps are provided at a usable voltage (above 10.5). So I'm assuming that 232 AH is a true number to use more or less if you have dual Interstate 6V's.

 

[Lornanaugle]

...we now only run the refrigerator on battery when we travel and it's hooked to our vehicle. Our manual states that we should not run propane while in motion.

Also, glad to see others are finding the mechanics and electrical overwhelming. I just don't understand it and your replies have simplified this topic for me. Thanks for responding and Thanks for asking the question!

L-