Wanting to add solar to Open Road 31SA

[J B Porter]

Seeking advice re solar controller, integration with factory charger, etc.
Thanks ! Model year 2014

[Jon_C]

All of the victron equipment ive installed, including their solar controllers have been bulletproof and the app monitors everything.

Just connect the new controller to your batteries and it will work just fine with your existing charger.

If you go with a battery monitor as well, be sure and connect the negative lead of the solar controller on the load side of the shunt so the monitor will show the solar charge current.

[zombiewoof]

I'd install three 200 watt 12V high efficiency monocrystalline panels (I think three will fit on your roof). The good ones out there are over 19.6% efficient. There is no need to make protrusions in the roof for the mounting brackets. My installer used marine grade two part epoxy to adhere the mounting brackets to the roof. It is totally bulletproof. I would install the panels in parallel to minimize the effect of shading on the panel array output. I would run 10 gauge marine grade wire from the top of the motorhome, (could use 8 gauge but it is a bit of an overkill given the output voltage of the 12V solar panels) down the A-pillar, and into whatever compartment you choose for the solar controller. I would install a Victron MPPT 100/50 solar controller, wire the output with 8 gauge wire, through a 40 amp fuse to a double pole breaker, and then to the positive and negative buss bars for the house batteries. I would also install a Victron 500 amp Smart Shunt between the negative terminal of the house batteries and the negative buss bar. Both of the Victron products are bluetooth and Victron provides an excellent app for their use.


If you can only install two 200 watt panels I would do everything the same except go to a smaller Victron MPPT 100/30, reduce the wire gauge to the batteries to 10 gauge, and use a double pole 30 amp breaker.


I had a larger 1.3 kW system added to my motorhome but it used the principles stated above.


Finally, there could be an argument made to put the solar panels in series. This would slightly reduce the voltage drop in the wire going to the controller, maybe .25 volts depending on the wire run length. It would also require a different higher voltage controller. The controller output wire size and wiring to the batteries would be the same. The tradeoff is with the shading effect. When wired in series the total shading effect of the series panels is equivalent to the maximum shading of any one panel. I read something recently that this may no longer be the case with some of the newest panels. Don't know for sure on this.

[J B Porter]

Jon_C,
Thank you very much !

[J B Porter]

zombiewoof,
Extremely helpful !
Thank you VERY much !

[J B Porter]

Jon_C,
In 1998 I bought a brand new HR Endeavor Cummins ISB !
Enjoyed it immensely for 20 years.

[Jon_C]

Originally Posted by J B Porter

Jon_C,

In 1998 I bought a brand new HR Endeavor Cummins ISB !

Enjoyed it immensely for 20 years.

Your welcome! Im really enjoying mine too!

[creativepart]

There is no real integration with the coach’s charging system. Your solar installation will be a standalone charging system directly connected to the batteries. Solar panels > solar charge controller > house batteries.

The solar charge controller does vary its output based on the battery voltage so when your coach’s charger is charging your solar charging will likely be reduced. But the reason will be the elevated voltage the main OEM charger will cause at the batteries.

Solar charging is a great partner to your coach’s OEM charging system… but not part of it, per se.

[J B Porter]

creativepart,
Very helpful. Thank you !

[PD Monkey]

I just installed 2 panels (3'x5' +/-) I think Sunpower. on my 2015 32SA. The panels are big and there was only one spot to fit both with the least amount of shading. I ran the wires through the roof at the fridge area. There is a small gap between the fridge and kitchen wall. From there, I was able to run the wires behind kitchen cabinets and down to the storage bay right next to the entry door. This is where I mounted the controller and Bluetooth module. It was the closest place to keep the wires from the controller to the batteries. I had all the equipment for months while I tried to research and figure out how to do it. Really, I was scared to start it. But once I got in there and started, I was able to get it all done in a day. No more running my generator every morning and night. Shoot me a message if you want pictures or more info, Disclaimer: I am not a electronics guy.

[J B Porter]

PD Monkey,
Thank you very much !

[J B Porter]

PD Monkey,
What wattage panels are your two ?
Do you have a residential fridge ?
How often do you now need to run your generator (dry docking) ?

[dssl]

Here is a past thread you may find helpful. Someone was asking for advice on how to install solar on a 32SA. In that thread I describe how I have my wires routed and where my controller is mounted.

https://www.irv2.com/forums/f106/32s...ll-525594.html

[J B Porter]

dssl,
Thank you !