How to deal with RV factory converter when hooking up solar

[Skwidward]

Hey guys,

So I've been planning out my solar install and thinking about removing my RV's factory converter and possibly installing a new 12V DC fuse panel in order to accommodate the new solar system.

However, I had this thought this morning: Why can't I just remove the wire and/or blade fuse from my RV's factory 12V DC fuse panel that runs between it and battery positive?

I'm talking about the wire that provides 12V power to the RV's 12V appliances from the house battery when you are unplugged (assuming RV is factory). This wire also supplies the charge from the converter to the battery and charges it when you are plugged in.

It seems like most people, when installing solar, remove the converter or at least disconnect it from the AC panel and the DC panel and bypass it. They also either splice into or run a new wire from their battery bank to the 12V DC fuse panel.

If I leave the converter where it is and my inverter is now providing "shore power" (from the new battery bank) to the AC breaker box, the converter will convert that to 12V DC and supply the DC fuse box. The problem with this is that the converter will want to charge the very batteries with the power that they are supplying. In order to prevent that surely I can just remove that "leg" of this system. Right?

[PNW_Steve]

I would keep the converter.

I depend on 12v for lights and furnace.

My converter supports those loads when it's cloudy or I a parked in the woods.

I called the manufacturer of my converter before connecting the charge controller to the batteries to make sure that they had no issues.

Works fine and doesn't require any manual intervention.

[ewarnerusa]

I've never heard of removing the converter just because you have solar? Solar panels -> charge controller -> batteries. The 120V AC stuff is not in the picture at all.
I do understand your last paragraph and you are right that if you are feeding your 120V AC system via an inverter then you need to disable the converter. I moved my converter power supply to its own dedicated AC breaker that I use as an on/off switch for it. I switch it off when I have my shore power cable plugged into the inverter.

[Skwidward]

My converter came with its own AC breaker.

I’m thinking if I’m parked and unplugged, I can turn off my converter and my inverter and just run off DC power. If I need AC power, I switch the converter and inverter back on but disable the battery charge line on the DC fuse panel (this is the same line that will supply DC power from the battery bank to the DC appliances when the inverter and converter are off).

When I’m plugged into shore power the inverter will be on, the converter will be on, and the battery charge line on the AC fuse panel will be off. The inverter will be charging my battery bank in this case, not the converter.

When I’m driving, the inverter will be off, the converter will be on, and the battery charge line will be connected; so my tow vehicle can charge my battery bank with the help of the converter.

I could rig up some switches to make turning things on and off a bit easier.

—

Another option is to, as mentioned in the OP, just disconnect and discard the battery charge line from the DC fuse panel altogether. If I do this, I won’t have to be turning things on and off. AC power will be supplied by the battery bank/inverter, and DC power will be supplied from the converter.

The only issues with this option are:

1.) My inverter will always need to be on when using DC appliances and not plugged into shore power (I don’t see this as an issue, as my inverter draws less than 1 amp/hr).

2.) This cuts out the tow vehicle charging my batteries through the converter while driving (I’m pretty sure that charge would negligible anyway, given my 300 ah lithium battery bank, but every little helps).

3.) I’ll have to rig the breakaway switch to my battery bank via another route now that I’ve disconnected the battery charge line.

[Skwidward]

...you are right that if you are feeding your 120V AC system via an inverter then you need to disable the converter...

If I'm unplugged and supplying AC power via my inverter, it's not that I would need to disable the converter, but that I would need to disable the battery charge line in order to prevent the inverter from charging the batteries with their own power. In this case I would want my converter working, as I would want it converting the AC power into DC power to power my lights, etc.

I would disable the the converter (and turn off the inverter) when unplugged and I only require DC power--this is if I have left the battery charge line intact (the battery charge line supplies DC power from the batteries to the DC fuse panel).

If I have disabled the battery charge line and I'm unplugged and want to use DC power, then I would need to do what I described in the above paragraph--turn on the inverter to supply AC power to the AC breaker box and turn on the converter to convert that AC power to DC and then supply it to the DC fuse panel.

My head is going in circles 😬

[NCmountainsOffgrid]

"It seems like most people, when installing solar, remove the converter or at least disconnect it from the AC panel and the DC panel and bypass it. They also either splice into or run a new wire from their battery bank to the 12V DC fuse panel."

'where' are you assuming this information from??? I know of NO rv owner who 'bypasses' or otherwise detaches their Converter simply because they have solar... it makes no sense.
The Converter is to convert 120v Shore or Generator power into 12v power usable by the 12v devices, lights, fans, and appliance controls within the RV. It also provides the 120v CHARGING to the batteries. There is no need or reason to bypass or remove it.

Solar is for charging your battery bank, simple.
Do no assume that you can run your 12v systems directly from solar, it is not designed for that.

[NCmountainsOffgrid]

and after reading some of your other posts/answers, I'm confused as to your 'setup' that you are conversing about...

you'll need to give us the full details of all of the systems that you currently have, type of rv(make/yr/model,etc), and any modifications you've made, or are thinking of making...

usually, RVs with Converters don't have Inverters, at least Inverters that also have integrated Chargers, and RVs with Inverter/Chargers don't have Converters(there would be no need for one)

[Skwidward]

and after reading some of your other posts/answers, I'm confused as to your 'setup' that you are conversing about...

you'll need to give us the full details of all of the systems that you currently have, type of rv(make/yr/model,etc), and any modifications you've made, or are thinking of making...

usually, RVs with Converters don't have Inverters, at least Inverters that also have integrated Chargers, and RVs with Inverter/Chargers don't have Converters(there would be no need for one)

I think there may be a bit of a misunderstanding here.

2018 Jayco Jay Flight 195RB travel trailer
6x 100 Watt Solar panels
3x 12V 100 ah lithium batteries
2000 Watt Inverter/charger with built-in 50 amp transfer switch
150/35 Mppt Solar charge converter

People disconnect, remove, or otherwise bypass their factory converter when installing solar in their RV to avoid having their converter try to charge their battery bank with the power it

EDIT: my posts keep getting deleted or cut in half

[ewarnerusa]

You don't ever want your inverter and converter running at the same time, otherwise you get the scenario you described in your OP where the battery is trying to charge itself using itself as the power source. It won't work.
If you're not plugged into any shore power and just running off DC, no need to do anything with your converter. Its AC breaker can be on or off, doesn't matter, because it had no AC power supply and won't be energized. Nor does the converter need to be on to allow battery DC power to pass through it and supply your camper DC power demands. So you don't ever need to disconnect the main DC line between battery and converter.

[Skwidward]

You don't ever want your inverter and converter running at the same time, otherwise you get the scenario you described in your OP where the battery is trying to charge itself using itself as the power source. It won't work.
If you're not plugged into any shore power and just running off DC, no need to do anything with your converter. Its AC breaker can be on or off, doesn't matter, because it had no AC power supply and won't be energized. Nor does the converter need to be on to allow battery DC power to pass through it and supply your camper DC power demands. So you don't ever need to disconnect the main DC line between battery and converter.

I hope this posts, because I keep losing posts. It's getting old.

I totally understand what what you're saying.

My my plan is to wire my shore power line into my inverter's "AC in" and wire the inverter's "AC out" into my AC breaker box where the shore power cord was originally wired into.

This way when when I plug into shore power my inverter will distribute AC power to the RV's AC breaker box and also charge the batteries (in a more efficient way than the factory converter).

This is is why I was thinking of disconnecting the main DC line between the battery and the converter.

[NCmountainsOffgrid]

the Converter/Charger for your RV is only going to be 'working' when you are plugged into SHORE POWER or otherwise using a generator to provide POWER, unless you trip it's breaker ...

[NCmountainsOffgrid]

solar incoming power from it's Solar Controller is only to be hooked up directly to your batteries, having nothing to do with your Converter/Charger

[Skwidward]

the Converter/Charger for your RV is only going to be 'working' when you are plugged into SHORE POWER or otherwise using a generator to provide POWER, unless you trip it's breaker ...

My inverter/charger will be pretending to be "SHORE POWER" but will, in fact, be battery power.

[Skwidward]

solar incoming power from it's Solar Controller is only to be hooked up directly to your batteries, having nothing to do with your Converter/Charger

....unless, it's wired into an inverter/charger, which is supplying AC power to the RV's AC breaker box....

[NCmountainsOffgrid]

solar is not 'wired' into a inverter/charger, only directly to the battery bank