RV shore power plugged into inverter run by 12v battery and 100w solar panels

[Mrssimmons19]

I have the ThunderBolt Magnum 4 25w Solar Panels (100w) Kit, that I use to charge my 12V battery and sometimes the 2nd battery for my RV to use my 750w power inverter for electricity in my RV, my question is when all that is hooked up like it's supposed to be and my inverter is ready to have something plugged in to power on would it be okay to plug in my RVs shore power cord (with 3prong wall outlet adapter needed) directly into my power inverter and have it run my RV like it would at campgrounds ect.....???? I've googled it in so many different ways and can't seem to get a direct answer that I understand fully. I'm new to all of this solar stuff and rv stuff. 

[time2rollagain]

Yes in general this works.  Works to the limit of battery capacity and two batteries may not last long.  And assuming this is a 30 amp RV really needs 3600 watts to run everything normal, the 750 watts will limit what can be run.

Microwave, A/C, electric water heater must remain off.  Fridge must be set to propane only or may draw 350 watts near continuous and drain the battery.  Most coffee makers etc are 1000+ watts.

Run a small tv, charge phones and a laptop is all good.  What else do you expect to run?

There are some inverters that cannot be connected to the RV system and the RV battery as they don't like the negative battery and inverter sharing the same ground.  Need to isolate the battery so that it connects only to the inverter.

[StirCrazy]

wow, 100 watt kit, thats good for trickel charging batteries if you have no draw, but that has been said before..   so Let me see if I got this right, you want to take your shore power and plug it into your inverter.  there are a few problems with this, first your 750 watt power inverter is that max or continuious?  realy unless you are just running a couple lights, or charging a laptop , or leaving the lights off and runnign a fridge thats about all its good for.  the second thing, is unless you unplug you're converter as soon as you plug in your going to blow the inverter so your not going to be able to charge your batteries, as that would just be silly using battery power to charge your batteries.. and that 100 watt solar panel set up isn't going to do nothing.  

what people don't seam to understand about solar is you have 4 to 6 hours of full panel output (or close to it) depending where you live, the rest of the time before is a ramp up and ramp down.  I average when it is all added togeather about 7 to 8h of full output in the summer and 5 to 6 in the winter, so inorder to be self sufficient with solar you have to be able to make all the energy you use in 24 hours in about 5 to 6 hours of solar output.  so my 5th wheel in the late fall when I am using the furnace could use about 100AH in 24 hours, so to replace that I have a solar system (480watts) that puts out 22amps duting the peak time and will recharge 99ah in aproximatly 4.5 hours so in the summer I am charge by noon usaly (less power usage) and in the winter I am at 100% before it gets dark.  I do want more but that is because I want to start running my bar fridge when camping also.  I also have four 6V batteries in there that will give me about a 2.5 day capacity in the winter, 3 or 4 day backup in the summer.. 

so there are ways to do it that don't realy break the bank, if you have to buy your solar system from the rv shop and have the install them then ya it is expensive, but if you cvan do it your self you could get a 400 watt panel for under 200 bucks in the US, a controler for under 150 so thats 550 for 800 watts plus 50 bucks for wiring and brackets...  

[MNtundraRet]

I hope you listened to "WaytoRoll". Otherwise; you are soon going to learned the hard way on your first trip out.

🤔

[way2roll]

Sounds like, instead of "rigging" the system into thinking it has shore power, you need more solar and more batteries and let the setup work they way it was designed. 

[Mrssimmons19]

I'd also just run it the same way I am now with the panels battery and inverter.

[Mrssimmons19]

I'm still getting on my feet in a new state new job still finding a place to park it for good. And until I'm able to have someone help install the solar panel system correctly I'm doing it the cheapest way I can. That's why I asked if you could plug the shore power cord into the inverter as a possible short term solution until I'm fully set up with solar correctly or have a place to plug into an actual better shore power system. I didn't know if it was possible to do or not I'm still figuring the whole solar stuff out all on my own with my daughter. She was trying to figure stuff out and thought hey is that possible to just do it that way obviously not all the time like a normal house or campground power system and not using everything in the camper like normal mostly just the wall outlets for tv mini fridge microwave(when needed) and small ac unit or space heater when needed and the panel system came with 2 lights that light up the whole thing so I wouldn't be using the camper switches for light. Or a water heater because I'm fixing all plumbing still. 

[way2roll]

Fridges and microwave (especially microwave) have pretty large amp draws. More than one battery can support. You either need more batteries and a way to keep them charged or a different power source. A generator would be a simple option although not cheap. Maybe find a state park that's cheap and has electricity, harvest host, etc. I appreciate the creativity and your position, but I am not sure you can perform what you are asking with what you have. 

[way2roll]

Not sure I follow. 100W of solar is a basically a trickle charger to keep your batts charged in storage. beyond that, you want to plug your shore power cord into your inverter to run things? If your inverter is wired correctly it uses your batteries to run your 120V appliances. And one battery isn't going to give you many AHs. Why wouldn't you just plug your shore power into an actual pedestal/outlet? Maybe I don't understand what it is you are asking. 

[Mrssimmons19]

I don't have a place to plug it in at the moment that's why I'm using the panels but my 12v battery doesn't last very long at all without having to be charged and that's only running my small fan at night and my 22" tv maybe 5hrs a day. I have my RVs 2nd battery that's supposed to run the inside but it's not working right now.  

[Mrssimmons19]

So I thought if I took my shore power cord and put it directly into my inverter hooked up to the battery and solar panels that it would work the same way it does plugging it into a regular outlet power source. 

[ewarnerusa]

I used to do it just like this, it works fine...but it is critical that you disable the onboard converter when doing so. Otherwise the converter gets energized by the 120V AC from the inverter and it tries to do its job of providing 12V DC charging. This will cause it to try and charge the 12V DC batteries while also drawing power from the batteries via the inverter.  An energy draining loop is created...

On my TT, the converter AC input was pigtailed into the AC breaker (GEN). I bought another AC breaker from the hardware store, popped it into an available slot in the AC board, and removed the converter power input from the GEN pigtail and wired it to the new breaker. Then I used that breaker as an on/off switch for the converter. You'll have to investigate how your converter is powered and find a way to disconnect it.

Also note that your whole camper 120V AC system will think shore power is available, so don't use things that are beyond your inverter/battery capacity or it will overload the inverter. Make sure a propane fridge is on gas only, water heater on gas, don't use the air conditioner or microwave or other high-draw AC items.

[Mrssimmons19]

Alright thank you I'll give it a try, I won't be using the water I have to fix all the plumbing stuff the only think I need to work is the wall outlets for my small tv mini fridge sometimes my microwave(when needed) and I have a small ac unit I use for the summer and tiny space heater in the winter but I won't have everything plugged in at the same time anyways. I'm still remodeling the whole camper so I don't need much all at once I just wanted to know if it was okay or possible to plug the cord into that kind of power system instead of a house or campground kind of system. Until I can get the solar panel system hooked up properly. 

[ewarnerusa]

I'm not completely clear on which of your batteries you are going to use to run the inverter, but in either case you would want the converter disabled so you are not trying to charge a battery with a battery. You will get the convenience of all the camper's AC outlets being live, just like if you were plugged into true shore power. But that doesn't mean it can operate just like when plugged into true shore power. A single (or even both 12V batteries working together in parallel) will not be able to operate much. Small TV no problem, mini fridge maybe for a short while, AC unit no chance, space heater no chance. The solar will not increase the capacity to operate things really at all, but it will provide a little charging when there are no other electric loads in use.

[way2roll]

This. 

You will need more or different power if you want to operate even minimal amp draw things for any amount of time. Microwave also will not work on one battery. If you want to go batteries, then you need more of them, and a LOT more solar or a way to charge them. Even then you are pretty limited, and you won't be able to run the AC and probably not a heater and will use up most of your amp hours with a microwave even on short bursts. This is a math problem. You have a certain amount of amp hours you need. Microwave takes X amps to run at Y length and frequency. How many amps does your microwave require? Add up the amount in a day you require it and total it. Same with your fridge, etc etc. Sum all the amps required for everything you plan on running and that is your total required amps to support usage. Then see how many batteries you need to support that demand. Then you have to consider the charge rate to keep your batts working while drawing a charge. I think you'll quickly realize that unless you are extremely frugal even with a large battery bank and a lot of solar, it will be challenging. By contrast a generator (which wouldn't really be more than a good solar set up - if that) is pretty endless with a power supply sans the fuel required to keep it running. Generator hours at any campground needs to be applied here. Another option is a cheap campground. Some state parks are as low as $25/night with electricity. Usually state parks don't have water/sewer but dump stations are an easy remedy. Geography is also a consideration. In the northern half of the US most campgrounds close in the winter. 

So, like I said before. Lots of factors. You need to know your need, what you need to support that need and the most cost-effective way to get there. 

Not saying it can't be done, but it's a math problem. And as with most things, usually throwing money at will solve most of those problems. Rving can be cheaper than conventional living but it has to be set up right. But it's not always cheaper.