Building a Solar System for our Motorhome..

[Keyair]

Been reading lots and trying to understand, but now its time to begin!

Background:
1984 345 Classic Motorhome, we live and will travel in the Western USA.
We are still working on the restoration, in a storage with no power.
We have the 7kw Kohler generator onboard, but I really dislike using it because of the cost/noise, plus I am just about to pull it out to soundproof the compartment. I only run it when I must... for AC etc.
There is a charger/converter onboard, a Fortron single stage 45a max unit, it works but I want it gone.
The battery tray is already modded to accept up to EIGHT 6V Golf Cart Batteries... I have 4 at this time.

The wish:
Want to keep the batteries charged when its in storage, Boondocking and running Microwave, TV's, and stuff, on the road without running the genset.
I want to also add a Thermostatic Fantastic Fan that will run and vent the heat from the interior when its in storage..

The basic plan:
We have already... 4 x 15w (60w total)HF panels... but I can use them temporarily, or elsewhere if they are a hassle to incorporate.
We also have a Uni-Solar FLX-32 flexible panel.

There is a lot of space up on top!
Took some measurements and am leaning towards putting 2 of the stick-on Uni-Solar 144w units on each side of the roof... at 216" x 16", I am pretty sure I can fit them. They will be stuck to another substrate not to the actual roof.
From there I could add more panels and batteries over time, as $, space and needs change.
Will need suggestions on Battery Monitors, solar controllers, etc..

Any thoughts, opinions and experiences will be welcomed!

Some pics...
Roof space...


Modded battery tray... deeper and wider.

[masseyfarm]

Just some general information that might be useful for your setup.

1) Any solar panel will produce more if its as cool as possible. So mounted above the surface with air circulation will be helpful.

2) You will want to space your panels so that you still have roof access to service other items on the roof. This means that large panels are hard to step around while on the roof, and easier to break accidentally. I have gone with 100W panels and sized for the area's I had available. These are all framed with alumiuium and easy to handle and mount.


3) Mono crystalline panels will give you more juice when not in direct sun. Most times when camping, you will want to park in the shade if possible.

4) Wiring harness from solar to controller to battery should be the largest you can deal with up to #8 ga if possible. Most controllers will accept #8ga wire. Use top quality marine wire. I used 8/2 safety (red/yellow) wire from West Marine.

5) When installing a controller, it is best located as close to the batteries as possible. Once you are familiar with the system, the information you get from the controller will be old news. The better, (higher priced) controllers have remote readers that you can install at eye level anywhere in the RV.

6)You did not confirm that you have your chassis start battery separated from your house system? If so, a 40W panel will keep you chassis battery ready to go, even if you are using the radio and a few lights on that circuit.

7)The circuit for the chassis battery should have a bypass installed so that this circuit can be switched to the house battery circuit while underway. Otherwise, the controller will shut down the solar charge because your alternator will override the controller cutoff.
This of course requires that you have a method of separating the chassis and house circuits while traveling so that the chassis alternator is not shutting down all your solar system. When you are travelling you have unhindered access to solar so why not use it.

I will add more later, but others might want to contribute their thoughts.

http://www.airforums.com/forums/f313...ml#post1287208

http://www.airforums.com/forums/f313...ml#post1283037


http://www.airforums.com/forums/f313...ml#post1021953
Dave

[richinny]

possibly mentioned in the above links is this site:
HandyBob's Blog « Making off grid RV electrical systems work
it has a lot of good tips including the hint to avoid shade on the panels from the air conditioners.

[Protagonist]

Originally Posted by Keyair

The battery tray is already modded to accept up to EIGHT 6V Golf Cart Batteries... I have 4 at this time.

I don't think there's a lot to add to what Masseyfarm said. Except, wire up the solar panels to bypass your battery disconnect switch; you want the solar array to keep charging your batteries even in storage when you've got everything else switched off. You can wire a separate in-line switch for the solar array (next to the charge controller would be good) so that you can kill power to the batteries if necessary when you're performing maintenance.

[DaveFL]

I second Protagonist on the switching. Keep in mind if you are powering an inverter and the solar isn't disconnected you will have 120v when you think the system is off.
In my limited experience, your controller is the most important part, PE panels vary in output up to 20 v it can boil off water in GC batteries in short order. As mentioned not all panels are the same, some a thin shadow (antenna, mast, branch) can stop some panels.

When you are servicing the 8 gc batteries be aware of the power the group has once wired, if you forget to take your arc welder it could be used rubber coated handles on tools help. I installed split hose over all hot connections for accidental dropping items.

[DanielB]

I've been researching some as well. So far this guy seems to be tops about knowing what he is talking about. Handy Bob he calls himself :-) HandyBob's Blog « Making off grid RV electrical systems work .

Due to his suggestion and because it seemed to make a lot of sense, I just installed a Trimetric 2025 RV monitor. With this thing you can see what is going on at any time with your charging and battery usage. TriMetric Battery System | Bogart Engineering

[Keyair]

Good Info!
Thanks everyone...


Looking at Charge Controllers...

Anyone have an opinion on the Blue Sky Solar Boost 2000E?
Its a 25A/12v max unit, which might work for me to start with...

Blue Sky Energy Inc. | Solar Boost 2000E

[OfftheGridRV]

The Blue Sky 2000E MPPT Boost controller is a very good solar charge controller for the price especially if you are limited in roof space to place extra panels. You will see output gains of nearly 30% if all the voltage settings on the back are set correctly. That sometimes can almost take the place of a single panel. It also comes with an equalization feature and optional temperature sensor compensation. Equalization is essentially a controlled over charge and should only be performed on vented liquid electrolyte lead-acid batteries and will improve battery performance and life.

Matt Bossert
Solar Specialist

[Keyair]

Looks like the Blue Sky 2000E has a lot of bang for the buck!

Here is my "starter panel"... or maybe the engine starter battery top-up panel!

[Keyair]

More goodies arrived..

Trimetric 2025RV and 500A shunt.


Info.
TriMetric Battery System | Bogart Engineering

Even if some of this is pushed aside for other stuff, I have another RV that will be the recipient!

[carl2591]

Originally Posted by Keyair

Looks like the Blue Sky 2000E has a lot of bang for the buck!

Here is my "starter panel"... or maybe the engine starter battery top-up panel!

has this company gone out of business.. i tried to surf to uni-solar.com and its a no go today june 27,13 tried google name and got something differnet.

[Keyair]

Yes, they did.
Panels are good tho.