Solar wiring question for RV

[JugglingSuns120]

I am looking to set up a solar panel on an old RV that my wife and I will be using for a cross country trip (not my usual expo rig but we are bring 2 friends and the space will be nice). I am looking for some advice/verification that I am going to wire this up correctly.

I have a Renogy 100W solar panel with Viewstar 20 AMP PWM charge controller. I will be running 2 house batteries for a total of about 200 AH of capacity with either 2 6V batteries hooked up in series or 2 12 volt in parallel.

The RV (1987 Minnie Winnie) is already wired with a solenoid to connect the house batteries and engine battery for charging while driving. I am wondering where electrically I should hook up the solar charge controller. I found some wiring diagrams from Winnebago that are very close to how my RV appears to be wired.

Chassis: http://www.winnebagoind.com/diagram/1990/099438.pdf

Body: http://www.winnebagoind.com/diagram/1990/099257.pdf

My plan was to connect the battery connection directly to the battery, however I am having trouble deciding where, if anywhere, I should connect the load from the charge controller. I understand I can't connect in any spot that would allow me to monitor all loads coming off the battery, if that's the case should I put a load on the controller? I will probably connect in to the refrigerator circuit if that is the case as it is already fused to 20 amps.

Thanks in advance for the help.

 

[jkam]

You shouldn't have to put anything on the load side of the controller if you don't want to.

I use 2 6v batteries from Trojan, T105's, instead of 12v ones with my RV and they work well.

 

[4x4junkie]

Agreed, you can just put the solar controller straight to the house batteries. That's what I do with mine when we go in my dad's RV (also a Minnie). Never had any issues with it interfering with the RV's systems (or vice versa).

 

[228B]

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I have a Renogy 100W solar panel with Viewstar 20 AMP PWM charge controller. I will be running 2 house batteries for a total of about 200 AH of capacity with either 2 6V batteries hooked up in series or 2 12 volt in parallel.

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I'm a big believer in keeping things simple. That's the "default" I start with and then I go from there. At first, I'd leave the Winnie's existing battery and wiring to itself. The Win's drivetrain alternator will be taxed trying to keep up with it's engine battery AND a 200Ah bank. Why invite the added electrical stresses? to an older vehicle.
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Your 100W Renogy is a good panel, but at best you'll see less than 6 amps from it. Before you take off, can you spring for a second panel? That would aid the effort in keeping that 200Ah house bank full.
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As for wiring, use 10ga copper 2-conductor from the rooftop panels to the charge controller. Place the charge controller AS CLOSE TO THE BATTERY BANK as you possibly can! to minimize volt drop. If you're less than 4 feet apart, you could get away w/ more 10ga... at what little amperage the controller will output, 10ga is ok. If you're more than 8 feet away, you should use #8AWG at a minimum, and, again, that's only for the 12 amps that system might produce.
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Here's the cool part:
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Wire up that separate solar rig as described above, THEN if you determine that the Winnebago's driveline alternator is a super-heavy-duty device and it's charge system designed to charge multilple batteries at once, you can connect the Winnie's alternator charging system to the house battery bank through a battery switch. Switch it off (disconnecting the house bank from the vehicle's charging system) when the vehicle is not running, then your house bank's voltage won't be robbed by any parasitic battery drain originating from the vehicle. When running down the road, the house bank can get a lil' more juice in addition to what the solar is putting in. As long as you're aware of which charging system is which and you know when to utilize each one, it's ok to have two, three, maybe four different "styles" of charger connected to the battery bank all the time. They'll push against each other, but nothing will blow up.

 

[JugglingSuns120]

After a bit more research I am thinking I will set it up as was suggested. When I first read through the manual for the charge controller I missed the fact that the load is optional, would have been nice to have the tracking of the electrical consumption but I am fine leaving that disconnected for this trip (A couple of weeks and then the solar system is likely coming off for our normal camp setup with my Jeep).

A couple more items related to general power consumption and the wiring from the RV. The setup to charge the house batteries is stock from the factory, it was not added in as an "aftermarket upgrade". I will double check the output capability of the alternator but I am not overly concerned with that at the moment.

I understand 100W is not a huge amount of power, however I suspect our consumption of power to be fairly low when the vehicle is parked over night. We will be using LPG for keeping the fridge cold which means the electric will just be running a small controller to keep that going. Beyond a light or two for a couple hours at night I don't anticipate a huge drain on the batteries. All of that being said another panel is not out of the question if a weekend away in the RV prior to the trip shows 1 to be insufficient for keeping the fridge controller going.

Thanks