I'm a big electronics/solar newbie.  My current solar set-up is a folding panel w/charge controller that clamps onto the battery--simple, effective, but not much energy, and I plan on going to 200--300 ah lion battery pack to run a fridge we'll be installing--in addition to furnace and lighting.  So, I want to install 300 watts or so of panels and run all the 12 volt stuff. No need or desire for inverter stuff.  Oh, I need to install a 12 volt station for charging phones.

So, here's my perhaps stupid newbie question(s):

Would it be possible to run the existing battery connections through a charge controller and then run the solar panels through their own charge controller, all feeding through busses, etc. and so to the lion battery pack?  That way the alternator + shore power would use the existing wires but be "controlled" for charging lion batts? Seems to me you just need to control how the batts are charged, and the existing wiring should be good for all the 12 volt stuff, yes?

Also, ideas on where/how to route wires from solar panels?  I've got a 2013 R178.

I'm a bit intimidated by the whole project, but I'm going to take it slow and make it happen.  Just getting my feet wet and my brain introduced to all this stuff.  Thanks so much for the collective wisdom here!

Cheers,

Scott

I am doing something similar for a 2013 Rpod 177.  I bought a SOK LiFePO4 12v 100Ah battery.  Because it's Li, I mounted it inside the Rpod under the seat near the electrical panel.  I found the 12v to the existing panel/converter and spliced in the battery.  I removed the lead acid battery.  In theory, I could patch the connections and add the external battery back in--it's reversable, but I don't intend to do that.   What I did not do is replace the existing converter.  Instead, in the splice I added a Victron BMV-712 smart battery monitor.  There's instructions for setting it up on youtube and at battle born battery's website.  This uses bluetooth to a phone app.  This device monitors the battery and controls the charge.  I hooked it all up and the converter started running its cooling fan, which made me nervous, but sure enough, the battery charged up, the converter shut down, nothing ever got hot, and it all runs perfectly. 

I have purchased a 200w solar panel.  I do not yet have a charge controller for it yet, but when I get one, I'll mount everything and patch it in.   The complicated part is that I'm going to run the cables down the space in the wall behind the toilet where my other control panels are mounted.  I have decided to buy a small access panel to install in the wall near the floor so I can manage the cables as they will have to go into the floor and follow the existing "conduit" along the bottom of the trailer to the battery and BMV.  The BMV unit has about 15 feet of cable to run the other direction.  I don't need it mounted as I have the app, but it will look good next to the charge controller and other panels.  I'm a bit nervous about drilling into the roof, but I have the cable mount and I know the right location so it shouldn't be too bad I hope. 

Like you, it's not a priority to hook it all up to 120v.  If I want to run my A/C or convection oven, I have a generator for that--there's not enough roof and space for all the power needed from solar.  That said, there are quality pure sine-wave inverters that I could install in the space near the battery and just have an outlet.  That's several hundred dollars at minimum for such an option however and it really won't run anything I'd want to run--it'd be just for the odd appliance, so it's not a priority for me.  Also, they have their own fans so I'd have to vent the space to dissipate any heat.   

Wow, guys!  Thanks so much for the feedback.  That BMV Smart battery monitor sounds like the ticket!  I'll look into it.  I was thinking I'd mount the battery somewhere like you suggest, Ottr.  I could put the LCD batt screen on the face of the cabinet below the seat there on the left side of the doorway facing out.  And with the blue tooth App, I'd have easy access to status.  So that monitor is the charge controller, basically, taking care that the 12v coming from whatever source in the RPod  is doing its thing properly?  I know not to put the solar panel charge controller in line with any other.  That would be a separate system going strait to the batts. via a buss connector. Now, how are you going to locate the correct place in the roof to drill for the solar panel wires?  That has me stumped.  I was thinking I might have to run them on the outside through black covering mounted along the side of the trailer where it would blend in reasonably and then have it come up underneath basically in the front where it would be easy to drill a hole for that and rerouting the existing battery connectors, but if I can get them straight into the roof and down, that would be much preferred.

PS:  Any chance you could post a pic or two of what you've done?  Oh, and where did you find the wires and how route them?

1. It allowed me to install a battery isolation solenoid so that the DC to DC charger would not be trying to drain the vehicle battery. It also isolates in reverse. The higher voltage LiFePO4 battery does not feed back through the connector and fool the alternator's controller into thinking the vehicle battery is charged. 

2. It allowed me to run a heavier gauge wire since the wire size in the Frontier's 7-way connector was inadequate for the load the DC to DC charger would have been drawing. In addition, Renogy specified the gauge wire to be used and the fusing. The stock Frontier wiring did not meet that specification.

3. Since I was relocating the battery to the inside, and installing the DC to DC charger inside, I would have needed to run wiring regardless. 

I tried running the DC to DC charger from the 12V circuit from the vehicle. It ended up being a situation where it was like the battery was trying to charge itself. I  found I needed to isolate the battery charge function from the regular RPod circuits for charging as opposed to load. Isolating the charging from the load side was the solution, thus my installation choices.

Other than that, I think you did a fine write-up of the changes needed. The converter would definitely need to be changed, but in some of the newer ones, the converter is not a separate module. That would be a complication. I saw a NoBo that was built that way. It is likely that the solar charge controller has a way to reprogram it, likely via DIP switches, so that it will not need to be changed. Even the DC to DC charger needed to be set for the LiFePO4 profile.

Yeah, referring to the existing AC to DC converter to make it Lion friendly.  Thanks!  I'll check that out.  But, yeah, I'll need the DC to DC converter, too, because I want to charge from the TV.

Jeez, I need a schematic!  At least a basic one.  LOL.  I think for obvious reasons I want to be able to charge from a land line, the TV, and the solar.  So it looks like three different parts:

1) AC to DC converter (basic swap)

2) DC to DC converter (for TV)--this one is more mysterious for me re. placement.

3) Solar charge controller--simple in line with the solar panels to the batts

So that covers it, yes?  Besides, of course, busses, fuses, etc.

My head hurts.

Thanks.

DC to DC: You can see where I put mine in my mods listing. I placed it near the battery. The drawings on Renogy's site are more geared toward a motor home where it will be close to the engine compartment and can be connected to a circuit that is only live when the ignition is on. That triggers the charger to turn on. When power is removed, that triggers it to turn off. On my installation, since i have the separate power circuit, I just draw power from that to the switch since it is only live when the engine is running and the isolation solenoid is closed. When the engine is off, the isolation solenoid opens and the circuit has no current. Thus, the DC to DC charger shuts off.

Solar: Yes, it is easy. Since you won't have the converter or the DC to DC charger trying to charge the battery, your solar panel's charge controller will handle the charging just fine. Connect it directly to the battery or run a connection to where you can use an Anderson PowerPole connector. Make sure to get the rubber waterproof boots to install as well so your connections stay dry both when connected or disconnected. These beat the solar MC4 connectors because it does not require a tool to disconnect them and they are much heavier duty so with something that will be plugged and unplugged many times, the Anderson PowerPole connectors are much better. 

If, like me, you mount the LiFePO4 battery and DC to DC charger inside the RPod, you will want connectors that are easy access from the outside anyway. The PowerPole connectors with the boots work well.