what runs on battery without inverter?

[alanmalk]

If the fridge on 12V is 350W as Alan said in post #20 then it is not really useful at all in my mind. ...

Whoops, senior memory moment.
Don't know where the 350 watt number came from. Looking at the specs I can see that 12V fridge operation uses 170 watts (the first number is the 120V power rating).

See the details in the thumbnail below.

And I did measure the voltage on the batteries with the fridge running on 12V while connected to the tow vehicle. At fast idle I was seeing 12.4V at the batteries with fridge on, and 13.8 with fridge off. Clearly my charging circuit is loosing considerable voltage between the alternator and the trailer batteries which I attribute to skinny wire, mostly in the truck. Bottom line, I can not run the fridge on 12V while driving and expect to arrive at a campground with charged batteries.

--
Alan

 

[Rossue2]

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.

My real world experience was: full sun on solar panel all day, then about 2 PM switched to 12V for fridge. Around 4 AM the alarm sounded.

Edit: dual 6V batteries were almost new as I had replaced the Group 29 12V and had never run them below 3/4 charged previously.

 

[vermilye]

My understanding is that when determining amp hours at a 20 hour rate, the amp hour capacity of the battery is divided by 20 (the hours) to determine the load that will draw it down to 10.5 volts in 20 hours.

For example, a 232 amp hour battery would have a 11.6 amp load (232/20). The problem is 10.5 volts is a dead battery. Do that too many times & it will kill the battery. Around 12V is considered 50% of a batteries capacity, and drawing it down more than that will shorten its life.

 

[dfandrews]

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.

I concur, with the exception: When using the Puget Sound Ferries, you must turn all propane off while on the vessel. The frig. then auto-switches to 12V DC.

(You then must remember to turn the propane back on, when you're back on land. Otherwise, your battery Will be drained. (Ask me how I know).

 

[parfsten]

So... seems like the installed inverter has limited use - I have it on my build list and am now wondering, since I mostly dry camp whether this will really have any practical value that a portable plug in inverter can't meet. Useful discussion... !

 

[rbryan4]

So... seems like the installed inverter has limited use - I have it on my build list and am now wondering, since I mostly dry camp whether this will really have any practical value that a portable plug in inverter can't meet. Useful discussion... !

Patricia, Alan and others have it right. If you plan to boondock, just determine what you want to run with it. If you go all 12V appliances and accessories, there's no need for an inverter. Regardless of which type of inverter you want to use, it has to provide the wattage necessary for that. In the case of our built in 1500W inverter, that gives us enough output to run most any appliance, at least for a short time.

 

[alanmalk]

So... seems like the installed inverter has limited use - I have it on my build list and am now wondering, since I mostly dry camp whether this will really have any practical value that a portable plug in inverter can't meet. Useful discussion... !

A few years ago when I was still 100% tent camping I purchased a quality portable 1000 watt pure sine wave inverter. The last 2 years I have used my new Escape for 85% of my camping. The inverter has been used exactly once in the entire period!

Someday I may be able to justify the expense to my wife... :ermm:

--
Alan

 

[rubicon327]

My understanding is that when determining amp hours at a 20 hour rate, the amp hour capacity of the battery is divided by 20 (the hours) to determine the load that will draw it down to 10.5 volts in 20 hours.

For example, a 232 amp hour battery would have a 11.6 amp load (232/20). The problem is 10.5 volts is a dead battery. Do that too many times & it will kill the battery. Around 12V is considered 50% of a batteries capacity, and drawing it down more than that will shorten its life.

This is my understanding exactly. My number of 21 hours was taking the battery completely down to 10.5V so I get why you cut my number in half now for a more realistic number. Fridge may alarm before it is allowed to get that low anyhow. Interesting to see Rossue's 14 hour example which shows even with full sun and solar the fridge on 12V is a hog.

 

[Jim Bennett]

A few years ago when I was still 100% tent camping I purchased a quality portable 1000 watt pure sine wave inverter. The last 2 years I have used my new Escape for 85% of my camping. The inverter has been used exactly once in the entire period!

Someday I may be able to justify the expense to my wife... :ermm:

--
Alan

That sounds like us, Alan. We have nothing to use that would draw that much. Even out tiny 200W one easily runs the TV and laptop at the same time, on the rare occasion we need it.

If for some reason in the future we find a reason to want one, I will just deal with it then.

 

[The Quilting Lady]

I concur, with the exception: When using the Puget Sound Ferries, you must turn all propane off while on the vessel. The frig. then auto-switches to 12V DC.

(You then must remember to turn the propane back on, when you're back on land. Otherwise, your battery Will be drained. (Ask me how I know).

Yes, I have read signs saying no active propane tanks in a few gas stations, tunnels and also before entering a tunnel that went under water. I figured it would be hard to get outside and turn it off in the middle of moving traffic. Fortunately ours wasn't turned on.

 

[War Eagle]

I ditto the "depends on your needs" crowd. The original owners of our all-electric 2010 EggCamper needed to run two 120V CPAP machines during the night while touring and boondocking in Alaska without solar. They mounted three 12V deep-cycle batteries on the tongue and ran dedicated high-quality wiring to a high-quality 1000W inverter mounted to a cabinet near the bed to run the CPAPs. They also upgraded their tow vehicle with a high amp output alternator and ran dedicated wiring to charge the batteries while driving during the day to their next camp site. Does everyone need to do that? Nope. But that's what they needed, and it worked for them. (On a side note, they also told us they plugged a 120V crock pot into the inverter and set it down in the sink to slow cook food while driving down the road during the day to their next destination. That way they always had a hot meal waiting for them inside the camper when they stopped to set up camp for the night, and their batteries were still topped off for the night. Again, it worked for them.)

 

[The Quilting Lady]

So my next question would be..... approx how many hours will the refrig in the 21 foot last on a tank of propane? I would be afraid I would use my propane up quickly.

 

[cpaharley2008]

Nancy,
Your quest for an answer is hard to fulfill as there are too many variables. You have experience with your other unit, how often did you refill the propane. Some people go through them in 2 weeks others, like myself have yet to refill both tanks, even after 2 years in my 21 and 2 trips across the country using propane. So it depends on your use.

 

[alanmalk]

So my next question would be..... approx how many hours will the refrig in the 21 foot last on a tank of propane? I would be afraid I would use my propane up quickly.

A very precise number from the Dometic manual, page 12, is 380 grams of propane per hour. But it is also almost totally meaningless number if you use your trailer like most folks. That is: You run the stove, furnace, hot water heater and perhaps a BBQ grill from your tanks at the same time you run the fridge. And how much do you use each, etc, etc.

In our camping routine we keep the trailer warm, cook, wash and shower quite a bit and go through a single tank in about 2+ weeks. This is what you will learn from experience. My vote for saving propane is to skip the showers but Susannah vetoed that idea. Same with paper plates. Go figure...

--
Alan

 

[algonquin50]

I always thought the inverter/converter ran everything...including 12v.
I would ask ETI as I know that I have never seen any camper run directly off of 12v bypassing the system. That would defeat the whole purpose of the 12v fuses, etc. It is also very easy to add solar to any system after you purchase. be glad to do a phone call if you think I know anything.

 

[thoer]

I always thought the inverter/converter ran everything...including 12v.
I would ask ETI as I know that I have never seen any camper run directly off of 12v bypassing the system. That would defeat the whole purpose of the 12v fuses, etc. It is also very easy to add solar to any system after you purchase. be glad to do a phone call if you think I know anything.

The converter that comes standard with the trailer converts the incoming AC into DC when the trailer is plugged into shore power. It also regulates the charging currents and voltages to the batteries while connect to shore power. Included with the converter are fuses for 12V lines and circuit breakers for 120V lines. 12V power runs thru those fuses, but the converter itself has no real application when running only off battery power.

An Inverter is an option on Escapes and it can invert DC back into AC to either one AC outlet or all the AC outlets depending on which optional model you opt for.

From the Escape site;

Inverter 1500W with one additional 120V outlet .
* This option will require Dual 6V Batteries $650.00
Inverter 1500W Includes Transfer Switch and all 120V outlets.
* This option will require Dual 6V Batteries $950.00

 

[float5]

So my next question would be..... approx how many hours will the refrig in the 21 foot last on a tank of propane? I would be afraid I would use my propane up quickly.

It is supposed to use less than a pound a day, however, I doubt that applies to hot weather.

 

[rubicon327]

I always thought the inverter/converter ran everything...including 12v.
I would ask ETI as I know that I have never seen any camper run directly off of 12v bypassing the system. That would defeat the whole purpose of the 12v fuses, etc. It is also very easy to add solar to any system after you purchase. be glad to do a phone call if you think I know anything.

All references in this post to 12V power implies through the WFCO power center which has the fuse block and converter section and separate 120V breaker panel. The inverter is a separate animal wired directly to the battery with 12VDC input and 120VAC output.

 

[The Quilting Lady]

Thanks everyone. I learned a lot. I don't need an inverter. I can run refrig on gas and not worry that it will run out anytime soon and I can do it while driving. A portable solar panel would be a good thing to keep my battery topped off. I will add a couple more 12 v plugs for boondocking.
Thanks, thanks, thanks!

 

[rbryan4]

I always thought the inverter/converter ran everything...including 12v.
I would ask ETI as I know that I have never seen any camper run directly off of 12v bypassing the system. That would defeat the whole purpose of the 12v fuses, etc. It is also very easy to add solar to any system after you purchase. be glad to do a phone call if you think I know anything.

As was already mentioned, the inverter is completely separate from the WFCO fuse bus and converter. The WFCO power distribution panel and converter are stock - an inverter is totally optional.

But, to your comment about where the power comes from, when we say the power comes from the batteries, that doesn't mean it is "bypassing" the WFCO. When you're boondocking, power is indeed coming from the WFCO, just like when you're connected to shore power. Question is, what's the real power source? It's the battery/batteries. So, batteries to WFCO, which supplies the trailer.

The only exception that runs from the batteries directly in my trailer is the power jack, because I connected it directly to them.