Solar Idea

The flexible battery plan is what I used way back when. I had a clamp steel battery carrier and jumper wire clamps and put the batteries in the bed. Twisted a marine switch from 1 to ALL and charged the batteries 2-hours on shopping trips. The old Chevy had a 130-amp Leece Neville alternator and I spun up 14.8 volts on the L79000 voltage regulator. The batteries started off at close to a 90 amp charge rate. A bit of work involved but that was before afforable solar. Thought my Honda gen and 50-amp Associated charger was hot stuff - 40-years ago :)

I have often thought of this same idea. I like NF CG's and they are always in the shade. Most of the time the tow car is in the shade also. I dry camp 95% of the time, but have minimal electrical reqs so don't need solar yet. Have you really thought through your reqs? How long do you plan to camp in one spot and how many amp hrs a day do you really think you will need? Maybe an interim plan would be to install the extra batteries in the tow car and use it as an extra battery bank without the solar. I'm not sure how you plan to camp but I usually go to a spot and park in the shade the explore the surrounding area in the tow car each day. That is a lot of alternator charging.

eb145 wrote:
if you put the solar charge controller in the rv and very close to the rv batteries, then you can use just 10 gauge wire on a fairly long run from the solar panels on the roof of your toad to the charge controller.

The important point is that the Charge Controller needs to be very close to the batteries they are charging, preferably with thick copper wires.

There is no need to overdo this last step. He will likely have 2*120 or 2*140W with PWM controller, max 15A current. Or something smaller yet. Even if he installs controller in his living quarters and runs a pretty long 10ft wire from battery to controller, #10 wire will do. #8 wire will be plenty. Copper, of course.

Controller likes being inside, away from heat, cold and humidity. Mine is living in my bedroom, wires running through a small hole in night table to the battery compartment below. Remote temp sensor is a must, if controller is not in the same compartment as batteries AND the battery temperature at any time varies more than 10C (20F) up or down from 25C (77F). The problem with cheap controllers is that they rarely come with remote temp sensor.

From panels to controller he can run #10 or #12, a usual MC4 extension cable, like This.

Though - it looks like I'm trying to do the job of his yet to be hired installer here :)

As many have pointed out in this thread, if you put the solar charge controller in the rv and very close to the rv batteries, then you can use just 10 gauge wire on a fairly long run from the solar panels on the roof of your toad to the charge controller.

The important point is that the Charge Controller needs to be very close to the batteries they are charging, preferably with thick copper wires.

Ed

RJsfishin wrote:
200 porta watts in series, controller in the RV, park toad anywhere you want, don't sweat a little voltage drop.

...and with a simple lock for that hitch pin, it can be made (more-less) theft-proof.

The OP point has been missed here - he wants to park his RV in shade. Keeping it in shade, while keeping the back out in the sun could be difficult. Has to be parked with back facing South, and without trees/palapa getting in the way.

There will be no voltage drop problem with panels on toad and controller with batteries in RV. Most panels on RV roof have 20-40ft cable run to controller. No problem with 200W PWM 12V, and no problem with 500-700W MPPT 24V.

200 porta watts in series, controller in the RV, park toad anywhere you want, don't sweat a little voltage drop.

mchero - most "flat" installs assume 4-5 degrees degrees tilt. Barely notable, doesn't affect the solar angle much, and allows shedding the water. You don't want it to be pooling on the panel. When conforming to the RV roof, this 4 deg slope comes naturally. On a toad, it may take some thinking and measuring.

Somehow I don't think that panels technology is improving so rapidly that one needs to replace panels in 10 years or less because some new better panels are available. These are not laptops. Since they've started covering panels with glass (some very old ones had plastic), there is not much to change.
When buying a new rig, many choose to leave old panels on the old rig and buy new panels as well, because of aging - panels lose 1% efficiency a year, so old ones have become 10% less efficient by then. You buy a new rig and want everything new, shiny and flawless - and it never happens, new rig comes with many deficiencies to fix, but this is another story :)... Also, effects of aging other than cells efficiency - glass may become a little scratched, connections in junction box oxidized, etc.

I put 4 250W high voltage panels on my roof FLAT. When I'm under trees it's most likey because I'm in an RV park and plugged in (rare).

When I'm boondocking I position the rig so that the panels get good sun all day.

Almot wrote:
10 years ago - yes, but today with $0.6-1.0 per watt the panels are not likely to be stolen.

X2 Plus the technology improves and the price has been dropping so one may decide to sell the solar and install new on the next rig.

Many other installs here.