Back when I first joined the forum I was seeking out information that would help me plan out my electrical system in the Cougar 26RBS I had on order. I was asked to post my progress when I finally got to installing. Well that time has come, so here’s some information on the progress I’ve made so far.
The plan I ultimately settled on was approximately 1,200 amp hours of lithium batteries, around 1,400 watts of solar, and a 3,000 watt inverter/charger. Yes, this is a bit overkill for most people. Probably a bit overkill for me too at the moment. The reason I’m going so big on the system is because my wife and I plan on doing a lot of off grid camping (if you can really call it camping at this point). Hopefully within the next few years it’ll be a lot of extended off grid camping as our ultimate goal is to sell our house and go full-timing for at least a few years.
What I’ve accomplished so far is the install of the batteries and the inverter/charger. I ended up going with 6 206ah SOK batteries. I stuck with a 12v system mainly because I really wanted the Victron multiplus ii 2x120 inverter and they don’t (or didn’t a few months back) offer a 24v version. So, all 6 are wired in parallel with 4/0 cable.
As of right now the batteries are still tied into the 12v system through the power wires for the auto level. Those wires were 8 gauge and a little small for my liking so I will be getting into the underbelly to find a better spot to tie them into the system. Hopefully that’ll be a next weekend project, depends on the weather.
As mentioned above, I bought a multiplus ii inverter. I haven’t really put it to the test yet because I just got that install done last weekend. I installed the inverter under the main bed, right next to the batteries. The positive battery cable is connected directly to the main battery bank positive using two 2/0 cables which is what was recommended by the Victron manual. I see others have just gone with a 4/0 which makes perfect sense to me, so I might swap to that. I plan to put a kill switch between the inverter and batteries and I think it’d be easier with one 4/0 cable vs two 2/0.
For those that aren’t aware of this floor plan, the bedroom is in the very front of the camper and the main power connections in the very back. So running the AC side of the inverter was a bit of a pain. The plan was to remove all nails from the coroplast on the driver side of the rig and make two runs of 6/3 w/ground cabling between the front and the back. What I realized when getting into it is there’s a whole lot of things in the way of those nails and also holding up the coroplast. So it wasn’t as simple as I thought it’d be and I wasn’t able to get it down quite as much as I wanted. The springs for the suspension were in the way of quite a long stretch and rather than fighting with trying to get my tools in there to get the nails off I decided to just shove a tent pole with some paracord attached to it from the front of the axles to behind them where I had the nails pulled out. Then used that paracord to pull the cabling through. That was a PITA though! My hands are pretty beat up from that experience.
The main shore power comes into the rig in the very back corner under the bathroom sink. It then dropped through the floor into the underbelly and across width wise to the main breaker panel. This made it pretty easy to splice into to install a Hughes power watchdog EMS. I then tied one of the inverter runs of cable to the inverter input. I pulled the other end of the original power cable down into the underbelly where I tied that to my second run of cabling coming from the inverter output. So, now the inverter powers both sides of the 50a rig.
Next steps will be to get the batteries tied into the 12v system a little better. I’ve had no problem using the camper as is, but have to be careful about power usage on the 12v side. Mainly being careful not to run the slide in while many other things are running (fridge, furnace etc). I have it appropriately fused for the wire size, so biggest issue would be blowing the fuse.
Hopefully in the next month or so I’ll also get started on the solar install. I’m going with flexible Renogy 175 watt panels. I had Renogy 100 watt flexible panels on the old rig and they worked out pretty good. I still have to verify wire size from the roof, but it was supposed to come with 8 gauge. If that’s true I’ll go with a 150|100 Victron smart solar charge controller and wire the panels in series to get a high enough voltage that the 8 gauge can handle the current. Then I’ll do a whole new run from the charge controller to the batteries of some nice thick wire (probably 2/0 or 4/0 have to check the ampacity and voltage drop calculators). If the wire from the roof is smaller than 8 gauge I may just have to figure out how to do a new run. I’ll also be pulling the factory installed rigid 200 watt panel off. I think I’ll be able to make that work with a couple 100 watt rigid panels I’ve used for a ground array. I’ll likely just keep those at my property for use their so I’m not lugging them around.
After the solar I think I’m done with the electrical system. Not too many other mods planned. I have a maxxair fan to install and would like to install one in the bedroom too. I was contemplating running some heat cable on the pex plumbing in the underbelly for when we winter camp, but based on my experience getting in there for the inverter install I might just skip that.
Other than that not much else planned.
I’m sure I missed plenty of detail, so feel free to ask any questions or point out any flaws. Added some pictures below as well.
Linear Mode
