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Pros and cons of plugging Shore Power into Inverter to power RV AC/DC

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austi003

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Oct 11, 2019
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My uncle has the Renogy 200W starter kit, and for years he simply plugs his shore power into Inverter when boondocking which allows him to use AC/DC in his 5th wheel like he was plugged into Shore. He obviously cannot use the A/C, but he can use lights, TV, water pump, hair dryer for his wife, etc.

I was considering doing a similar setup in my travel trailer now, but wanted to see the Pro's/Con's. In Will's videos and books, he recommends a fuse bank to wire 12V appliances into, so it made me wonder if plugging shore into the Inverter is a bad idea.

I understand there will be some efficiency losses due to the DC (Battery Bank) --> AC (Inverter) --> DC (Converter for 12V) conversions, but do not yet know enough to know if the losses are significant enough to not consider doing so.


One other side question from one of the comments on his 400 W DIY video... he mentioned running a ground from the Inverter to the negative terminal of battery bank. I was under the impression I needed to run inverter ground to a vehicle chassis ground. Am I effectively grounding the inverter if I just run it to the negative battery terminal?
 
Deno said:
If you're setting up your own house wiring, such as in building a van interior that had none before, then yes you always fuse your 12v lines. Unless you like unexplained smells and fires in small spaces. Most deaths are from smoke inhalation, not burning alive.
Click to expand...
I fully understand the purpose of fuses. I did not plan to run new line off of my battery bank to connect back to my 12V sources. That is why I'm trying to understand if I can run my shore power through the inverter or whether that is a bad idea.
 
Are you saying he plugs the Rvs shore power plug into the inverter which is being powered by the batteries? There by powering the RV as if it was plugged into a outside shore power source?
Battery powers inverter-inverter powers RV thru the shore power cord which then charges the battery?
If that’s what your asking I wouldn’t think that’s a good idea.
 
MrNatural22 said:
Are you saying he plugs the Rvs shore power plug into the inverter which is being powered by the batteries? There by powering the RV as if it was plugged into a outside shore power source?
Battery powers inverter-inverter powers RV thru the shore power cord which then charges the battery?
If that’s what your asking I wouldn’t think that’s a good idea.
Click to expand...

Mostly correct, except that the shore power cord would not charge any batteries. I would use the battery disconnect on the main house batteries as I do not want the RV Converter attempting to charge though off my solar battery bank. My Solar battery bank will be completely separate from the main house battery.


My other option is to wire my solar setup directly back into the main power system of my unit, that is just beyond my level of comfort or knowledge and I'd rather not pay for a professional install
 
Deno said:
I think OP's uncle has an inverter-charger.
Click to expand...
I'm not trying to charge any batteries... just trying to get my solar battery bank to power the RV's main system (via Shore plug) without needing to do the advance install of connecting back into the wiring of the main unit. He is able to plug the shore cable into his inverter, so I know it works, I just don't know at what cost or what it might be doing to his batteries longer term.
 
Oh he is talking about inverter chargers. They do not convert dc to ac then to dc. It has a seperate converter circuit for battery charging, thats all. A good one to buy right now is the victron. Ul listed and high quality, low stand by consumption.

And yeah, I would just go with an all in one unit as other people mentioned above. Has charger/inverter/ats etc. Its easy

And the losses are very small in any of these systems. The biggest self consumption will come from inverter standby. The latest victron has a low self consumption, but costs a ton. The MPP all in one units are moderate. If you buy an older inverter charger, the inverter standby will be horrid.

But yeah, they are a good option. What pros and cons beside self consumption were you curious about?
 
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Deno said:
Without looking up Will's videos on the MPP all in one units, as that should be something for you to handle, what you are describing on your relations trailer is an inverter-charger. It's meant to run off mains voltage (aka 'shore') and do whatever charging of the batteries etc is necessary. They've been around for awhile. And yes the trailer has 12v lights. Yes they run off the batteries. And yes the inverter/charger is maintaining charge on the batteries. Nothing new..

Since you're building your own setup and want to simplify, the all-in-one units are an inverter/charger plus MPPT. You plug in batteries, solar, and shore power and it does the rest.
Click to expand...

I have looked at his post on MPP and unless I am misunderstanding, that is not what I'm looking for. I will be boondocking 99.9% of the time without access to traditional shore power. What I am trying to do is simply plug the cord into my inverter so that it will allow me to use 110v plugs, TV, etc. directly off of my solar battery bank. The RV converter would also take the juice coming from the shore cord and convert to 12v for my main 12v systems in the unit.

The MPP appears as though I need to run extension cords from the TV, fridge, outlets, etc. back to the MPP, which is not what I'm wanting to do
 
And grounding inverter to chassis is unnecessary unless you want to save money on wire. No reason to do it otherwise. If your inverter is far from the batteries, ground to chassis. It is not a true earth ground to dissipate excess charge so there is no benefit minus cost savings on wire
 
Oh no, you can connect mpp output to a circuit box or panel. Or ATS. No problem. I can power a house AC panel with my current mpp. They go up to 15kw of power. You can run a small village from it
 
Will Prowse said:
Oh he is talking about inverter chargers. They do not convert dc to ac then to dc. It has a seperate converter circuit for battery charging, thats all. A good one to buy right now is the victron. Ul listed and high quality, low stand by consumption. Like this one: click here

And yeah, I would just go with an all in one unit as other people mentioned above. Has charger/inverter/ats etc. Its easy

And the losses are very small in any of these systems. The biggest self consumption will come from inverter standby. The latest victron has a low self consumption, but costs a ton. The MPP all in one units are moderate. If you buy an older inverter charger, the inverter standby will be horrid.

But yeah, they are a good option. What pros and cons beside self consumption were you curious about?
Click to expand...
I think I am doing a terrible job of trying to communicate what I am asking, or else I am completely misunderstanding what you guys are trying to tell me. If I purchase an MPP for example, would I not have to figure out how to run the coach lights back to it, and then run the Microwave, Fridge, or TV cord back to it? I'm hoping to take advantage of the units existing wiring without needing to specifically wire my inverter back to the unit's AC system. My uncle successfully plugs his shore into a solar inverter and it seems to work just fine, I just don't know what losses in efficiency he might unknowingly be experiencing, and/or what he might be doing to his batteries or inverters if that is actually not a good idea for him to be doing.
 
Will Prowse said:
Oh no, you can connect mpp output to a circuit box or panel. Or ATS. No problem. I can power a house AC panel with my current mpp. They go up to 15kw of power. You can run a small village from it
Click to expand...
Ok, I guess I need to research the MPP a bit more to understand how it would hook back in then.
 
Well the inverter will have a data sheet that will tell you the standby/efficiency. and it can vary quite a bit. so I would check those numbers if you are concerned about the losses. each one is different.

run the coach lights back to it? And yeah, if you want to run those appliances, hook it up to your existing AC panel. Then your inverter, whether its mpp or not, will run it all.

Could you draw a picture?
 
Will Prowse said:
Well the inverter will have a data sheet that will tell you the standby/efficiency. and it can vary quite a bit. so I would check those numbers if you are concerned about the losses. each one is different.

run the coach lights back to it? And yeah, if you want to run those appliances, hook it up to your existing AC panel. Then your inverter, whether its mpp or not, will run it all.

Could you draw a picture?
Click to expand...
Yep, let me work on a little diagram to explain my current setup and what I'm trying to understand
 
austi003 said:
I have looked at his post on MPP and unless I am misunderstanding, that is not what I'm looking for. I will be boondocking 99.9% of the time without access to traditional shore power. What I am trying to do is simply plug the cord into my inverter so that it will allow me to use 110v plugs, TV, etc. directly off of my solar battery bank. The RV converter would also take the juice coming from the shore cord and convert to 12v for my main 12v systems in the unit.

The MPP appears as though I need to run extension cords from the TV, fridge, outlets, etc. back to the MPP, which is not what I'm wanting to do
Click to expand...
Ok now I understand. You want to power everything the shore power would normally power ,All the Ac outlets and the Rvs normal 12 accessories thru existing wiring. But disconnecting or switching off the Rvs main shore powered inverter charging circuit so it isn’t charging the battery as it would normally. You just want to make use of all existing outlets and 12v powered things thru the added inverter by simply plugging existing shore plug into the inverter. But still having the ability to have your solar charging working to keep the batteries up.
And as Will was explaining,The MPP would basically do it also. You would simply plug the shore power cord into the MPPs ac out plug. Batteries and solar would also connect to the MPP.
You wouldn’t need the separate CC and inverter. The MPP has it all.
 
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MrNatural22 said:
Ok now I understand. You want to power everything the shore power would normally power ,All the Ac outlets and the Rvs normal 12 accessories thru existing wiring. But disconnecting or switching off the Rvs main shore powered inverter charging circuit so it isn’t charging the battery as it would normally. You just want to make use of all existing outlets and 12v powered things thru the added inverter by simply plugging existing shore plug into the inverter. But still having the ability to have your solar charging working to keep the batteries up.
And as Will was explaining,The MPP would basically do it also. You would simply plug the shore power cord into the MPPs ac out plug. Batteries and solar would also connect to the MPP.
You wouldn’t need the separate CC and inverter. The MPP has it all.
Click to expand...
Oh ok, so same concept I'm trying to do with an Inverter... If I already have a charge controller/inverter, is the MPP worth it though?
 
austi003 said:
Oh ok, so same concept I'm trying to do with an Inverter... If I already have a charge controller/inverter, is the MPP worth it though?
Click to expand...
IMO The MPP units work quite well and everything is in one attractive container. I have the pip812 12v 800w version for a van build but changed my plans.
The 24v ones would work much better in your RV situation. Just a bit higher initial costs. More inverter power and 24v works so much better you would need to add two more 6v batteries for 24v. You only need an inexpensive 24-12v reducer for your 12v stuff.
Some don’t care for them because everything separate is easier to fix if a problem arises with individual components. These have been used everywhere and are said to be very dependable. Which way ever is easier for your needs.
 
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The way I have powered my bus conversion (converted 30 years ago) was to wire the ac plugs directly to shore power. So when plugged in to shore power the 110 outlets in the bus would be live. I also have a converter that plugs into one of the 110 outlets.This converts the 110 power to 12v .d.c to power lights, water pump,etc. So when plugged into shore power I have 110 AC and 12V DC.The converter would also charge the battery(but not very efficiently). This system initially ran off the start batteries. At some point I added 2 "house" batteries (and separated them from the start batteries)so as not to run the start batteries down. The house batteries run all the 12v DC things when NOT plugged into shore power. Then I added solar to charge the "house batteries" only. Prior to that the "house" batteries were charged off the engine alternator. At the same time I also added a 1500W inverter to give me 110v AC off the house batteries.The inverter goes to a 110vAC plug. I then plug the "shore power" cord into the outlet from the inverter. So basically to get 110AC power I either plug the shore power cord into a 110 power outlet in a campground or plug it into the plug connected to the inverter. Its simple and works for me. In addition I have a "Smart Gauge" which tells me what % of battery power is left in house batteries and a Baylite digital gauge(with shunt) to monitor the power going into house batteries from solar. Hopes this helps answer some of your questions.
 
Freddmc said:
The way I have powered my bus conversion (converted 30 years ago) was to wire the ac plugs directly to shore power. So when plugged in to shore power the 110 outlets in the bus would be live. I also have a converter that plugs into one of the 110 outlets.This converts the 110 power to 12v .d.c to power lights, water pump,etc. So when plugged into shore power I have 110 AC and 12V DC.The converter would also charge the battery(but not very efficiently). This system initially ran off the start batteries. At some point I added 2 "house" batteries (and separated them from the start batteries)so as not to run the start batteries down. The house batteries run all the 12v DC things when NOT plugged into shore power. Then I added solar to charge the "house batteries" only. Prior to that the "house" batteries were charged off the engine alternator. At the same time I also added a 1500W inverter to give me 110v AC off the house batteries.The inverter goes to a 110vAC plug. I then plug the "shore power" cord into the outlet from the inverter. So basically to get 110AC power I either plug the shore power cord into a 110 power outlet in a campground or plug it into the plug connected to the inverter. Its simple and works for me. In addition I have a "Smart Gauge" which tells me what % of battery power is left in house batteries and a Baylite digital gauge(with shunt) to monitor the power going into house batteries from solar. Hopes this helps answer some of your questions.
Click to expand...
If I'm following correctly, it sounds like you are doing the same general concept I was planning to do.
 
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