Community Forums

JeffinTD · 12-31-2010, 09:46 AM

So I'm looking at putting about 200 watts worth of solar on my toyhauler, possibly up to 300 watts.

I'm wondering about charge controllers, and am wondering which way to go is best. I'm willing to pay for extra efficiency, but don't need the most fancy or expensive one.

I figure it would be MPPT type, and am wondering about the Morning Star Tri-star 45 amp, or Blue Sky's 2000E MPPT 25 amp job.

Any other suggestions?

Does someone sell a kit with wiring, mounting, panels, and controller?

Most of the pre-done kits I've seen have been low end stuff, with either a cheap controller or no-brand panels....

Thanks in advance.

Gary RVRoamer · 12-31-2010, 08:02 PM

The folks who hang out on the Boondocking forum have a lot of experience with solar - I'll bet they will have some ideas. Solar is a frequent topic there.

UFO Pilot · 12-31-2010, 08:15 PM

I see a lod of good things written about the Morning Star Tri-Star 45. I have the Morningstar Duo but I only have 1 - 130 watt panel.

Bob/Becky D - VA · 12-31-2010, 09:23 PM

I have found that Jack Mayer's site has provided the most comprehensive discussion of determining solar requirements, discussion of various components, and installation procedures.

RV Electrical

Bob

SpursMVP · 12-31-2010, 10:01 PM

You might wish to read this thread. I participated in this while installing my panels and the people in here gave great directions/advice.

http://www.irv2.com/forums/f93/solar...rks-66571.html

By the way...the installation of our 400 watt system was not to difficult.

JeffinTD · 01-01-2011, 04:18 AM

Thank you guys for the most excellent reading.

I think I was on the right track with the TriStar MPPT, but was under shooting my wiring.

I was thinking of #8 from junction box to controller, and #4 from controller to battery bank, but after getting educated I'm going to run #4 and #2 or larger. The controller having separate wires to sense voltage at the battery now also seems like a nice feature.

I also wondered about series vs parallel, and this reading helped.

hardy1000 · 01-01-2011, 06:30 AM

I use the Blue Sky 2512i for my 300watts and it works great. It is an MPPT controller.
Blue Sky Energy Inc. | Solar Boost 2512i & 2512iX

ralper · 01-01-2011, 11:17 AM

hardy1000,
Your controler is border line for the # of panels you have. It is not at all adjustable like a Morning Star Tri Star 45 is. The controler must be near the batteries (within 6') for a proper installation. Controlers must be adjustable to your system's configuration.

Controlers should be a bit oversized for the application they are being applied to. If they are too small they will burn out.

akadeadeye · 01-01-2011, 01:39 PM

You might want to check this out also. This is one of the RV couples on iRV2 who have recently gone through a solar panel installation. This is Part 3 of 3.

RV Solar Part III – The Installation | Wheeling It

Don

hardy1000 · 01-01-2011, 02:59 PM

Quote:

Originally Posted by ralper

hardy1000,
Your controler is border line for the # of panels you have. It is not at all adjustable like a Morning Star Tri Star 45 is. The controler must be near the batteries (within 6') for a proper installation. Controlers must be adjustable to your system's configuration.

Controlers should be a bit oversized for the application they are being applied to. If they are too small they will burn out.

I have my controller in compartment next to batterys (about 2' max). I purchased the BlueSky when I had 200 Watts and picked up the third panel from a friend very cheap. I use the J box from a company in Oregon to tie my panels together and into the controller. So far everything is working very well. I agree I am close to the limit but still within specs. I only wish it had the adjustable charge input feature.

HandyBob · 01-02-2011, 10:20 AM

Quote:

Originally Posted by ralper

hardy1000,
Controlers should be a bit oversized for the application they are being applied to. If they are too small they will burn out.

Right on Ralph! Ralper here is one of the few who read the directions (pretty smart for a retired plumber); he has an SB50 with 400 watts and it is NOT overloaded. His system works, but I still don't like the SB50. Seems to me that a $500 plus controller should not have pots in it for any adjustments. A shaking & rattling RV is no place for that kind of product. It belongs in a house that does not go down the road. Last week I adjusted a friend's 2000e that had vibrated its voltage set point pot until the voltage was up at 15.5V & the guy's batteries were a mess of corrosion. However, the batteries were fine and well charged, just messy. I get that most retired RV'ers don't understand electricity enough to see these problems, which is why the things installed in RV's need to be reliable.

There are a LOT of Blue Sky controllers out there with too many panels hooked up to them. It seems that the dealers think they only need to look at the amps the panels produce and forget about the possible boost. The directions are clear on this issue. There is no excuse, except that most of those guys have had absolutely no electrical education. Anybody idiot can start a solar business and a lot of them have. I have even seen systems with the panels in series (higher voltage / lower amperage) and sized for the input amps, not output. Absolute stupidity! The possible boost goes away if the controller is rated at a lower ampere output than the system could produce because the controller will not let more go through it than it is rated at. If your controller gets hot to the touch, it is only a matter of time before it fails. (I said hot, not warm.)

I have had this conversation with many people, some with controllers overloaded as much as 30%. A couple of years ago I talked to a guy with five 130 watt panels. When I asked what controller he was using he said he had two 2512 Blue Sky controllers. I told him one was overloaded & he responded with "b#*#@t, you don't know what you are talking about". Then after I pressed, he admitted that it had already been replaced once under warranty. I saw that same rig just the other day and now it has six panels on it. Probably under wired, not seeing any boost and I have to wonder about the controllers. However, I am not stupid enough to stop and ask him. People who spend all of that money are very defensive about their non working systems. People love their overloaded Blue Sky controllers. I call it the Mercedes factor. Never ask a man who bought one if he likes it, even if it is broken down at the side of the road.

My Morningstar Tristar has a huge finned heat sink and it never even gets warm. Are there cooling fins on your Blue Sky?? No, I am not selling Morningstar or solar panels. I am just trying to get people to wake up to what is happening out here and to realize that the profit motive is hurting a lot of us. A $200 Tristar is a lot better tool for charging batteries than a $300 plus "budget" MPPT controller, but those guys make a lot more profit selling you things with more mark up built into them.

Read my RV Battery Charging Puzzle. It has been extensively revised.

JeffinTD · 01-02-2011, 02:34 PM

As I'm sorting through stuff, I'm thinking about this for a system...

2 Kyocera KD135GX panels. 10ga MC4 cable for a short run to a junction box with bus bars. Not sure if I should go parallel or series. I figure 6 mounts per panel. Is that enough?

From there, 4ga welding cable down to the controller. Maybe a 12' run. I've decided the fridge vent is too far away from the batteries, so I'll run conduit down the corner of the closet opposite of the stairs.

Then the Morningstar Tristar 45 amp MPPT controller mounted near the passenger side landing jack, and maybe a 5 or 6' run of 2 ga cable to the batteries.

I'll be installing the RM-2 remote panel, and probably run 16ga tray cable from batteries to controller for the voltage monitor (shouldn't have any amperage at all to speak of on those).

I'm not sure what kind of fuse block to install.

I also want to put in a meter of some kind, but I'm not sure which one.

Maybe some day if I retire and get to play more, I could see adding 2 more 135 panels. If I do that, I'd for sure run each pair of panels in series. That should still have me under the 45 amp capacity of the controller, but would that be too close?

Also, any suggestions for a vendor? Preferably some place I could order everything in one place (stud rings, adhesive shrink tubing, and all the other misc stuff) at a competitive price.

Thank you all for the input.

a k · 01-02-2011, 03:14 PM

Are you running those big cables from the solar panels?

HandyBob · 01-02-2011, 07:48 PM

Jeff:
I usually don't respond to questions like this, preferring to help people one on one via email, but since I am lurking and this could help others.....
You are free to email me if you like. My address is in the profile & also in my blog. If you send a request, I will respond with a couple of photos that will be helpful to you.

10 gauge is fine for the panel feeds as long as they are individual, or two in series. However, be very careful about connecting in series because a shadow will affect both. On RV's where you might be forced to park partially under a tree this is not usually a good idea.

4 mounts per panel is plenty. Even with tilting mounts this is what is usually done.

Conduit is not needed. Not that it is bad, just a waste when using welding cable. If you want to save some money, go to Walmart and price their US made, 20ft, #4 booster cables.

You can use the excess #22 wire from the temperature sensor for the voltage sense wires. They carry NO current. You should fuse this for safety.

Your main fuse block: You evidently have not carefully read my blog. A fused two pole air conditioner disconnect works very well for this. Not UL listed for home installations, but safe & cheap.

The meter (or battery monitor) is more important than the remote (which should be considered an option) and a Trimetric 2025-A or -RV (take your pick) is what you want. This is worth its weight in gold. Don't forget the shunt. bogartengineering.com This can be connected with #22 twisted pairs (again, fused). You need only two pairs for one battery bank & one more wire for a chassis battery connection if you need it.

That controller will actually handle up to 600watts on 12V with no risk of overload. Four 135W panels on 12ft of #4 cables at 12V is no problem. The instructions for the Tristar have the voltage drop charts that you need and these can be downloaded from morningstarcorp.com. Three 200 watt plus grid tie panels would overload it and require the 60amp model.

Finding a one source vendor will not likely be possible. For instance, Northern AZ Wind & Sun thinks that they must sell you $.75 a ft #16, 3 pair cable for the meter when it is never needed in an RV. This is the hardest thing to find reasonably & that is why I now carry the stuff around with me. You can buy a lot of things you need locally. Also, don't get hung up on Kyocera. There are bargains to be found. You should be considering big grid tie (24V or higher) panels if you have the room for them (since you already decided to spend the money for the MPPT, which I would argue is wasted on only 270 watts). Three panels (other than Kyocera) and the standard controller would cost less & give you more. You can buy 195watt panels for what the Kyoceras are going for, but the freight can be killer. Dollars per watt and warranty are all you should worry about. Best of luck in your quest for power!