Very new Travel Trailer Off Grid Solar set up question...

Moleman65

New Member
Joined
Jan 15, 2022
Messages
7
Hey y'all,

Forgive me if this has been discussed but I'm very much a newb to this. My wife and I are slowly prepping and learning so we can go off grid and homestead in Colorado. We bought a 34' Travel Trailer and threw on a Renogy system. 4 100w panels, the charge converter and the big 12v 200AH hybrid gel battery. Currently have a small 1000w invertor. I plan on upgrading the invertor to something like 3000w or 4000w but my question revolves around the converter and shore power set up. IS IT SAFE and possible to hook up the invertor (the upgraded one) to the shore power hook up to power the whole trailer. I apologies again if this has be asked. I just signed up for the forum and wouldn't mind any and all feed back.
 

jberger

Solar Enthusiast
Joined
Jun 1, 2021
Messages
214
The inverter is there to turn your 12v-DC battery output into 120V-AC for use by your appliances, etc. When you talk about hooking up an inverter to power the trailer from shore power, that step would appear to be un-necessary, its already AC.

Normally, you would have an Automatic Transfer Switch (ATS) that would allow you to switch between shore power, inverter power and generator power. So if you wired your inverter up correctly, then you could use all 3 sources in the trailer.

Some of the all-in-one inverter systems include the ATS and inverter in the same box. Check out the Victron Multiplus II. https://www.victronenergy.com/inverters-chargers/multiplus-ii
This one will get you battery charging, ATS, inverting, power boost (for those times when you need a burst above the regular limits for a short time) all in one box.

Hope that helps, or at least makes sense.
 

Moleman65

New Member
Joined
Jan 15, 2022
Messages
7
The inverter is there to turn your 12v-DC battery output into 120V-AC for use by your appliances, etc. When you talk about hooking up an inverter to power the trailer from shore power, that step would appear to be un-necessary, its already AC.

Normally, you would have an Automatic Transfer Switch (ATS) that would allow you to switch between shore power, inverter power and generator power. So if you wired your inverter up correctly, then you could use all 3 sources in the trailer.

Some of the all-in-one inverter systems include the ATS and inverter in the same box. Check out the Victron Multiplus II. https://www.victronenergy.com/inverters-chargers/multiplus-ii
This one will get you battery charging, ATS, inverting, power boost (for those times when you need a burst above the regular limits for a short time) all in one box.

Hope that helps, or at least makes sense.
Like I said I'm very new to the game, seeing what I can do to make the system work. The travel trailer's basic systems, like the Lights, one charging port, electric water heater, tank heaters (to prevent the water tanks from freezing), water pump and fridge can run off the battery, oh and the slide out functions, BUT, the TVs and other regular AC plugs and such don't run off the battery. I either need shore power or a generator plugged into the shore power port, which then via the converter back charges the battery as well. The location of the converter is under the fridge and is absolute rats nest of wires. The battery being located on the tongue, I had to keep the invertor near it by about 4 ft, specs from Renogy. that set up is approximately 20' straight shot from the convertor under the fridge. I'm not sure where I would be able to wire it to the ATS you mention. I'm trying to do as much DIY as I can. Reluctantly if I have to go to an RV place I know they will over charge for labor. You put me on the right track so I hope the additional info helps you helps me. I appreciate your input and advice.
 

Browneye

Dr. WattSon
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Nov 2, 2021
Messages
1,071
Location
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4000 watt inverter?
Perhaps you're trying to run air conditioning off your batteries?
In simple terms, 4000 watts AC takes about 400Ah of battery. You would run your battery out in 15 minutes. Not to mention cabling to carry that kind of amperage.

An LED TV draws about 65W AC - about 5Ah on 12V. Your 1000 inverter should be no problem.

Why do you need to run your slide-outs?
 

jberger

Solar Enthusiast
Joined
Jun 1, 2021
Messages
214
Short version, if you don't understand RV electric, please pay the dealer to install this stuff correctly, it's easy to get it wrong, especially grounding, and end up in a dangerous situation.

I'm going to try and be very simple and descriptive, just to make sure we aren't missing anything.
Ok, so you have a 12v power center in there today, that connects your 12v loads to the battery bank. I think that is what you are describing "The travel trailer's basic systems, like the Lights, one charging port, electric water heater, tank heaters (to prevent the water tanks from freezing), water pump and fridge can run off the battery, oh and the slide out"

Is it fair to assume that the 12V power center included a built-in battery bank when you bought it?

You added a 1000W inverter and a battery, plus a little solar to help charge that 200ah battery or you replaced the trailer's original battery with the 200ah battery. I'm not clear if you have 2 batteries that are separated (one for the trailer loads, one for inverter) or just one that everything ties into. I assume your inverter has a couple of 120v outlets on the back and you just plug in what you want to run from it and it's separate from any of the power center wiring.

Now you want to adjust the setup so that the inverter is hardwired into to 120v outlets on the trailer, and you can switch between using a shore power connection, generator connection and using the inverter to make 120v AC from your 12v 200ah battery.

If all that makes sense, here's what you could try.
Your shore power cord is probably already wired into the 120v side of power center so you could just use an adapter and plug it into the inverter. This would give you 1000W of power on the 120v side of the house. You would need to turn off your battery charger (it's just wasting energy to try and charge the battery from itself) and any large loads like AC, etc. as they would quickly exceed your 1000w available.
Check your outlets and make sure you can get power at each one, this will let you know if everything is wired into the same input on the power center.

You would add the ATS in between the shore power connection and that panel, to provide power from either source.

Don't go overboard on the inverter upgrade. As long as it handles the microwave, you don't need anything more. Typically, the larger the inverter, the larger the stand by losses. No need to burn battery when you don't need to. You aren't going to run an Air Conditioner or Heater off of a 200ah battery for long, so just keep it small and manageable.
 

12VoltInstalls

…myself everything do I…
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if you don't understand RV electric, please pay the dealer to install this stuff correctly, it's easy to get it wrong, especially grounding, and end up in a dangerous situation.
From what I saw working at a service center there aren’t any dealers with any competency to modify or install solar or 120VAC- they are parts replacers.
That just doesn’t seem like good advice.
 

luckielab

Solar Enthusiast
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Nov 26, 2020
Messages
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@Moleman65, if you haven't already stumbled across it, check out the "Vehicle Mounted Systems" sub-forum. There are a few good build threads there from folks with travel trailers.
 

Bvillebob

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Oct 21, 2021
Messages
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One thing people often pay enough attention to is idle power draw of inverters. A cheap 3-4 kw inverter is likely to consume most of the power your 400 watts of panels generate just sitting there doing nothing all day. Pay attention to the idle power specs and remember it's 24x7, 50 watts for 24 hours is 1.2 kWh per day of wasted power. Better inverters waste less power, my 4 kw uses 18 watts at idle.
 

12VoltInstalls

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cheap 3-4 kw inverter is likely to consume most of the power your 400 watts of panels generate just sitting there doing nothing all day. Pay attention to the idle power specs
Smaller inverters can be <30W at idle. Mine is.
Just a cost of being off grid that one extra panel can easily pay.
 

Moleman65

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Jan 15, 2022
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Nice, there is a lot of solid information here. I appreciate it all. Yes I plan on living off grid and will need the inverter to run 24/7 to keep power to the refrigeration and run various small appliances including the microwave but also instapot or air fryer type things. I can and do plan on adding more panels. I have room on the roof for maybe 8 more panels if necessary, however I plan on doing a power shed to plug into eventually. I do facture in idle waste. As for clarity on the other stuff I will reply directly to those posts. I don't necessarily plan to run AC, I'm in Colorado and the land I plan on being on shouldn't get terribly hot that I'll need it. I was contemplating upgrading the propane furnace to a DC operated furnace I found online, but it wont be used much as I'm also installing a wood fire stove in the RV for main heating. The DC furnace would be in the event the woodfire burns out and it gets below a certain temp.
 

Moleman65

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Joined
Jan 15, 2022
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7
4000 watt inverter?
Perhaps you're trying to run air conditioning off your batteries?
In simple terms, 4000 watts AC takes about 400Ah of battery. You would run your battery out in 15 minutes. Not to mention cabling to carry that kind of amperage.

An LED TV draws about 65W AC - about 5Ah on 12V. Your 1000 inverter should be no problem.

Why do you need to run your slide-outs?
I just want to make sure I have all the power I need, minus the AC, the 2 exhaust fans with windows up tend to keep the trailer relatively cool in the 80-90 degree summer weather we went through last summer. As for the slide outs I just mentioned that because those are on the standard battery systems.
 

Moleman65

New Member
Joined
Jan 15, 2022
Messages
7
Short version, if you don't understand RV electric, please pay the dealer to install this stuff correctly, it's easy to get it wrong, especially grounding, and end up in a dangerous situation.

I'm going to try and be very simple and descriptive, just to make sure we aren't missing anything.
Ok, so you have a 12v power center in there today, that connects your 12v loads to the battery bank. I think that is what you are describing "The travel trailer's basic systems, like the Lights, one charging port, electric water heater, tank heaters (to prevent the water tanks from freezing), water pump and fridge can run off the battery, oh and the slide out"

Is it fair to assume that the 12V power center included a built-in battery bank when you bought it?

You added a 1000W inverter and a battery, plus a little solar to help charge that 200ah battery or you replaced the trailer's original battery with the 200ah battery. I'm not clear if you have 2 batteries that are separated (one for the trailer loads, one for inverter) or just one that everything ties into. I assume your inverter has a couple of 120v outlets on the back and you just plug in what you want to run from it and it's separate from any of the power center wiring.

Now you want to adjust the setup so that the inverter is hardwired into to 120v outlets on the trailer, and you can switch between using a shore power connection, generator connection and using the inverter to make 120v AC from your 12v 200ah battery.

If all that makes sense, here's what you could try.
Your shore power cord is probably already wired into the 120v side of power center so you could just use an adapter and plug it into the inverter. This would give you 1000W of power on the 120v side of the house. You would need to turn off your battery charger (it's just wasting energy to try and charge the battery from itself) and any large loads like AC, etc. as they would quickly exceed your 1000w available.
Check your outlets and make sure you can get power at each one, this will let you know if everything is wired into the same input on the power center.

You would add the ATS in between the shore power connection and that panel, to provide power from either source.

Don't go overboard on the inverter upgrade. As long as it handles the microwave, you don't need anything more. Typically, the larger the inverter, the larger the stand by losses. No need to burn battery when you don't need to. You aren't going to run an Air Conditioner or Heater off of a 200ah battery for long, so just keep it small and manageable.
I have a couple resources to help figure out the wiring, like mentioned below most dealer shops don't do custom work and in my short experience and the experience of others I know finding a dependable, TRUSTWORTHY dealer is insanely rare in the RV world.

Yes the travel trailer came with a standard smaller 12v battery. It was small and wasn't holding a charge so I upgraded it to the 12v 200ah one. It is connected to the factory connection to the trailer systems. The solar charge controller is then attached to the same batter and the invertor as well on top. And yes I'm trying to see if the invertor can safely be plugged into shore power to power the other systems that don't typically run off the battery but shore power only. My travel trailer isn't designed like.... a toy hauler that is more designed for boondocking out in the desert to play with ORV toys. It's designed to park at RV camp sites that have shore power. Thank you for the suggestion to turn off the A/C and convertor. A quick look at the panel they both have their own breaker switch. So I will experiment turning off the convertor and still using shore power to make sure there aren't any negligible effects. As I stated in another reply, I shouldn't and don't plan on needing the A/C system during the summer and I'm trying to reduce the heat use as well. The whole goal is to be able to reduce the propane usage and use the solar as much as possible. If I need to add more panels I planned on it, as well as a second same sized battery. Per Wills advice with invertors I plan on going slightly bigger than I THINK I need so that I have plenty. The 1000w invertor I can use on the solar system on the mobile work shop and use most things so it wont go to waste. I figured a 4000w invertor for the Travel trailer would be solid to cover all my needs without hick-up. I planned on at least 4 more panels with the additional batter and the needed larger charge controller to handle the system. My main concern was running the short extension cord to the shore power (yes I have the adapter) from the invertor to power the other systems. Thank you for your input and insight.
 

Moleman65

New Member
Joined
Jan 15, 2022
Messages
7
One thing people often pay enough attention to is idle power draw of inverters. A cheap 3-4 kw inverter is likely to consume most of the power your 400 watts of panels generate just sitting there doing nothing all day. Pay attention to the idle power specs and remember it's 24x7, 50 watts for 24 hours is 1.2 kWh per day of wasted power. Better inverters waste less power, my 4 kw uses 18 watts at idle.
I appreciate the insight. IF my assumption works, it won't be idle overnight it'll be in use for the refrigeration and minor things like phone charging etc.... it would be running 24x7 so I do plan on adding extra panels and maybe an additional battery to compensate. Although Colorado gets around 300 days of sunshine a year I want to plan on having enough power to run at least a couple days comfortably. I do have a back up generator I can charge the batteries with if they do get drained too quickly.
 
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