Advice on solar (and some LP advice...)

[Calbick Campers]

Hey guys! I was just hoping to get some advice on adding a solar setup to my rig and make sure I have a decent understanding of what I'd be getting myself into once we take the plunge. I have absolutely no electrical experience, I've never wired anything myself, never changed out a light or anything of that sort so all the terminology and items are new to me. If I need to be corrected, please do!


So full disclosure, the work I will be doing is not going to be on a skoolie. My girlfriend and I owned a bus a couple of years ago and things didn't pan out with our storage situation (or legality situation...) so we got rid of it before doing anything at all to it, sadly. We're picking up a 70s Winnebago tomorrow that has been fully gutted so it's almost like picking up where we left off where it's time to start building things back up instead of tearing them down, and we're excited.


So firstly, being that it is a motorhome, there is wiring present for an on-board battery that is separate from the one in the engine bay. We have been told by the previous owner that all of the wiring for this is intact and will charge off of the alternator.



I'm wondering for this if it would be best to just use a single 12V car battery? How do you determine what amperage to use, just match it to the one the motor requires? I've read in a couple of places in my solar research that using two 6V golf cart batteries in tandem costs the same, but works better and lasts longer. Is this the case?


Secondly I'm also wondering if the battery (or batteries) charged by the motor would be best used to power coach lighting, one in each "room". Is that reasonable?


As far as an actual solar setup, I was thinking of just using the regular old Renogy 200W 12V kit which has two 100W panels and a charge controller. To make sure I get it right, the wiring runs from the panel to the charge controller. The controller runs both to a ground and to a battery bank where I would have two 12V car batteries, or...? Could I just get two 12V car batteries and also hook up the cable that runs off of the alternator so I ultimately just have one battery bank that can be charged by the engine and the panels?


Anyway, from the batteries I run cable to a DC to AC inverter. Would a 2000W inverter be appropriate? From here it just runs to the receptacles, right? I'm not looking to run much off of these, maybe some late night TV and charge a laptop and phones or something.


Is a breaker needed somewhere in the line? How about shut off switches?


I'm also curious about shore power. Where would this tie into this setup? If the camper has an air conditioner, would this somehow run directly to the shore power hookup?


We're also looking at using an LP tank to use with a cooktop and a space heater, and maybe the fridge? Any experience with this?


Sorry for the word wall, I'm just determined to figure this stuff out so I can do it myself but I can't find explicit answers for someone as clueless as I am. I find that the posts that explain these things don't quite dumb it down enough for me, and even so, I believe my setup is a little different.


ANY advice is appreciated, thanks!!

[Calbick Campers]

Come on guys, no feedback at all?!

[JDOnTheGo]

Too much to cover in detail but I'll take a wide swing...

Originally Posted by Calbick Campers

I'm wondering for this if it would be best to just use a single 12V car battery? How do you determine what amperage to use, just match it to the one the motor requires? I've read in a couple of places in my solar research that using two 6V golf cart batteries in tandem costs the same, but works better and lasts longer. Is this the case?

A typical car battery is a 'starting' battery so is not designed for the type of use that a house inflicts on it. 6V batteries are. Read some articles on the differences. In short, a bank of 6V batteries will provide better & longer service (when properly cared for) than starting batteries (to include what are typically called "deep cycle" batteries).

Originally Posted by Calbick Campers

Secondly I'm also wondering if the battery (or batteries) charged by the motor would be best used to power coach lighting, one in each "room". Is that reasonable?

An engine driven alternator is not designed to properly charge a 'house' battery. Read up on 3 and 4 stage charging. The alternator doesn't have a chance to properly charge a battery when connected to multiple banks. The only good way to do this is with something like this product from Sterling.

Originally Posted by Calbick Campers

As far as an actual solar setup, I was thinking of just using the regular old Renogy 200W 12V kit which has two 100W panels and a charge controller. To make sure I get it right, the wiring runs from the panel to the charge controller. The controller runs both to a ground and to a battery bank

That much (above) is correct. However; you can't know how much solar you "need" until you do an energy audit. If you want to guess and just be happy with the results, you certainly can take that approach. IMO, any solar is better than no solar.

Originally Posted by Calbick Campers

Anyway, from the batteries I run cable to a DC to AC inverter. Would a 2000W inverter be appropriate? From here it just runs to the receptacles, right? I'm not looking to run much off of these, maybe some late night TV and charge a laptop and phones or something.

Cables (plural - positive and negative). Only you can answer what size inverter is appropriate. What items do you need it to power? Do you need pure sine wave or will modified sine wave suffice?

Originally Posted by Calbick Campers

Is a breaker needed somewhere in the line? How about shut off switches?

Breakers and fuses protect the wire. They should be installed in any wires/cables of any significant length.

Originally Posted by Calbick Campers

I'm also curious about shore power. Where would this tie into this setup? If the camper has an air conditioner, would this somehow run directly to the shore power hookup?

The 110VAC power/breaker panel is typically powered via a transfer switch. The transfer switch has two inputs (one output). Shore/Generator power is one input, the inverter is the other.

Originally Posted by Calbick Campers

We're also looking at using an LP tank to use with a cooktop and a space heater, and maybe the fridge? Any experience with this?

That is the typical RV approach and works while providing flexibility. The negatives to an absorption refrigerator is that they are kind of expensive, not very large, not easy to install, and sometimes not super good at what they do (meaning, the ice cream is frozen but just barely). If you plan to do a lot of boondocking, they sip the propane while providing cold storage.

[o1marc]

As JD touched on, you need to compile a list of every electrical appliance you will be using in the bus. Finds it's start up needs and running needs and add it all together to determine how much solar or battery power you need.