HiI apologize if this has been covered before. I finally managed to get my solar system connected. I tossed out the old deep cycle 12v and replaced it with (2) 6v 215ah golf cart batteries. They are of course just powering the TT 12v system. I had been reading some discussions where some RV owners could run everything, including the furnace off of their batteries. Many had only one battery on the system. If that's the case, it seems like I could disconnect my batteries from the 12v system and instead connect them to a proper inverter and plug it into my TT's main shore connection. The big question is, how well would this work out in practice? I am not sure how to figure out if two batteries would make it all work. Under normal circumstances, we will not be using the furnace. And we can keep the A/C turned off if necessary. But it would sure be more convenient to power the 12v system AND the AC outlets from one connection. Any opinions??

Sure you can do that. Of course no AC. Some limited Microwave and hair dryer use if need be. You will lose a little power when inverting but not that much. When you put in your inverter you need to be as close as possible to your battery's. I put in a 2k inverter and can do what you are talking about. The thing is though is I bet your trailer runs well on 12 volt as well as your furnace. The only reason I put in the inverter is so I could run a 120 refrigerator. Anyway there are some people here that are very knowledgeable on the subject, they can tell you about wire gauge and inverters etc. JMHO

Maybe I don't understand the question but every TT I have owned has a 12V furnace, so why would you need 120V? The only 120V items are the AC, microwave and some of the outlets but the furnace will run on 12v whether you are plugged into shore power or not.Did I miss something here?Gerry

fitznj wrote:Maybe I don't understand the question but every TT I have owned has a 12V furnace, so why would you need 120V? The only 120V items are the AC, microwave and some of the outlets but the furnace will run on 12v whether you are plugged into shore power or not.Did I miss something here?The OP obviously has a limited understanding of his trailer's dual electrical system ... he's simply asking if it's possible to connect an inverter to run his trailer "whole house" and as already indicated the answer is "Yes, of course". I did just that with a 1000 watt sine wave inverter, installing it in my trailer's front pass through storage compartment where it would be out of the weather, well ventilated, safe from those with sticky fingers, but close to the tongue mounted battery. Currently I power it with just a single G27 battery so my use is limited but within those limits the trailer behaves just as it would when plugged into shore power. With dual 6 volt batteries the OP is even much better off so if cost isn't an issue I'd suggest he invest in a quality 2000 watt sine wave inverter and install it in a similar fashion. Yes, he could set it up with an automatic transfer switch for even more convenience but I find that simply plugging the trailer's main service cable into the inverter when shore power isn't available works just fine. Sure, a larger inverter idling does draw more power than a couple of smaller inverters just turned on as required to feed specific devices but the convenience of powering everything running on 120 vac, including all the receptacles, can't be beat and especially if a remote is mounted inside the trailer a larger 2000 watt inverter can also be turned on/off as required, limiting any unnecessary draw on the battery. Pics of my own installation (7 pics).

If you disconnect your batteries from supplying the 12V system, your lights & furnace will not work.A solution that seems much simpler & less expensive to me:Install a couple of 12V outlets, get a couple of small portable inverters with AC outlets & USB outlets, and plug the small inverters into the 12V outlets. Use the inverters to charge your electronics & watch TV. You can also use the portable inverter in your vehicles. And you are not out a fortune if one of them dies.Depending on the size of your trailer & the number of people using it, you may only need or want one outlet & inverter.You can also use the 12V outlets for 12V appliances.Of course if your heart is set on using a hair dryer and/or microwave, you will need a 1000-2000 watt inverter wired to your 120 V system. But either one of those by itself will suck your batteries down in less than an hour of use. Your solar system will have to do some fast recharging to keep those batteries above their preferred 50% charge state. If you pull them down below 50% you will dramatically shorten the battery life.

Running entire TT off batteries | Good Sam Community

38 Replies

EsoxLucius
Explorer
Aug 27, 2015
I replaced the OEM Dometic RML8555 absorption fridge with a Nova Kool RFU6800. Like it a lot. The 12 volt, 5.2 amp draw is easily handled by 635 watts of solar and 440 amp hours of battery capacity.
MrWizard
Moderator
Aug 26, 2015
the Engle Novakool and comparable 12v fridges will out perform residential 120v fridges power wise
use less power and keep cooler, most of them can double duty as a full time freezer (if you wish)
they have lots of top quality insulation to keep the box cold and reduce cycling
and the compressor uses 50% or less the power of a same cu-ft 120v residential
fridge
my next fridge is going to be 12v Dan Foss compressor
Veebyes
Explorer II
Aug 26, 2015
Crabbypatty wrote:
I purchased my inverters from donrowe.com. This is what they do and wouldn't buy a cheap inverter especially when running some watts. I now have a 2000 watts Xantrax Pro Sine Inverter. The Pro Sine is needed for todays sensitive electronics, other wise you can damage their circuits. So go cheap on inverters then start replacing lap tops, tvs, disc players etc. Soon you will realize that the more expensive inverters are actually reasonably priced.

Very similar to my setup. My 5er is now setup like a cruising boat. All 12V needs are drawn from the battery bank. No more cheap & nasty converter/charger. The 2000W inverter charger provides pure sine wave power to those sensitive AC circuits & power supplys to laptops & chargers. Good insurance for long service life of devices.
Crabbypatty
Explorer
Aug 26, 2015
I purchased my inverters from donrowe.com. This is what they do and wouldn't buy a cheap inverter especially when running some watts. I now have a 2000 watts Xantrax Pro Sine Inverter. The Pro Sine is needed for todays sensitive electronics, other wise you can damage their circuits. So go cheap on inverters then start replacing lap tops, tvs, disc players etc. Soon you will realize that the more expensive inverters are actually reasonably priced.
westend
Explorer
Aug 26, 2015
JiminDenver wrote:
westend wrote:
JiminDenver wrote:
if we all had to do it one way, most of us would be disappointed.
True dat. :B That's almost signature material, Jim.

I run a 120V fridge and all of my 120V entertainment gear (Disc player, stereo receiver, TV--thinking about adding a turn table, too :C) off 235W of solar and 315AH of batteries. I use a Xantrex Prosine 1000 W inverter. the inverted power is currently distributed to a single receptacle and the fridge by direct wire. At some point, when I have more batteries, more solar, bigger inverter, and wish to run an A/C, I'll install a transfer switch so everything is seamless.

Thanks.

How big is your fridge and how much does it draw. I'm considering adding a energy star 2 or 3 ft mini fridge for the longer trips. I'd love a two door but they are a few inches too tall.

Would a Engel or such be a better choice? Maybe except the solar puts out more power than my wallet does money. Minis go cheap on CL. ;)
1.8 cu ft.---draws 80W. 1/4 duty cycle. I am limited by height in the location. I might add another along side this one. AFAIK, any of the DC compressor fridges will draw about 3-4 amps/hr. With nearly the same duty cycle. ISTR, it would be 4/5 the power draw compared to a 120V fridge but 8 X the initial cost.
Vulcan_Rider
Explorer
Aug 22, 2015
Almot wrote:
Vulcan Rider wrote:
Except for the little red multi-meters, I don't trust any of their {Harbor Freight} electronics.

Oh, those $5 multimeters :)... Yeah, if you only need to know whether there is "some" DC in the wires, and positive or negative. Half-decent meters start from $20-30.

My experience is somewhat different.
I've had 3 of them.
All were accurate to .1 volts DC on the range used for automotive systems.
Within a couple of volts at 110 VAC.
Don't know how accurate the ohmmeter is but you can easily tell the difference between 100 ohms and 1000.
My only complaint is the lack of a minus sign for DC voltages.....so you really can't tell the difference between positive and negative.....except for the red and black probes.
Almot
Explorer III
Aug 22, 2015
Vulcan Rider wrote:
Except for the little red multi-meters, I don't trust any of their {Harbor Freight} electronics.

Oh, those $5 multimeters :)... Yeah, if you only need to know whether there is "some" DC in the wires, and positive or negative. Half-decent meters start from $20-30.
Almot
Explorer III
Aug 22, 2015
JiminDenver wrote:
I'm considering adding a energy star 2 or 3 ft mini fridge for the longer trips. I'd love a two door but they are a few inches too tall.

Would a Engel or such be a better choice? Maybe except the solar puts out more power than my wallet does money. Minis go cheap on CL. ;)

Engels sell fast on CL, and not too cheap. They are popular. I forgot the name of some cheaper Chin-gel clone from Ebay that people are also satisfied with. "Star"-something.

Novakool also have a decent reputation (not to be confused with Norcold), but they only make built-ins, not portables. They have some 7 cu.ft 2-door side-by side model that is low but wide.

Tundra - now Dometic - is about the same. Except for Engel, they all have German Danfoss 12V compressor, so the differences are minor. (Can't say about Ebay clones though).

12V a "better choice" than standalone 110V?
Portables have never been too efficient, they are too small, and thin lid. Can be noisy too, since the motor is not hidden in the cabinet.
Built-ins? If you add insulation (standalone 110V already have enough), expect it to be 10-15% better - since there is no inverter loss. And 4 times more expensive.
Veebyes
Explorer II
Aug 22, 2015
When choosing an inverter, be careful what you buy. Cheap is just that. Saves some $$ short term but could cost big time in the long run.

There are sine wave inverters, the cheap ones, & there are pure sine wave inverters, the much more expensive ones. Sine wave inverters do not produce the same AC as your house current or shorepower. Pure sinewave inverters do.

Powering very sensitive electronic things with a sine wave inverter is asking for trouble. Oh it is not likely to self destruct on the first use with a regular sinewave inverter but over time there is the very real risk of something expensive giving out because it is not being powered by pure sinewave AC as it was designed to do.

So, for anyone planning to use an inverter for anything more than the very rare occasion, a good education on the differences between sinewave & pure sinewave inverters is in order.
Vulcan_Rider
Explorer
Aug 22, 2015
youwillforget wrote:

Harbor Freight has cheap inverters

Except for the little red multi-meters, I don't trust any of their electronics.

I got a "heavy duty" 3 range battery charger and it is junk.
It might make a good boat anchor.....as it is HEAVY.

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Running entire TT off batteries

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