Latest mod, solar panels

[Darrens02]

[daddio]

Nice! Looks good

[RVnut]

Do they tilt up?

[Darrens02]

Thanks for looking. yes they can tilt, from either side.

[RVnut]

I would love a system like that but dont ever see it in the budget

[Darrens02]

RVNut,
You might be surprised, My cost are higher because I live in Alaska, but total I don't think I have more then $1,600 into a 540 watt system that works on 30 volt panels, going into a mppt controller that gives me up to almost 40 amps into my battery bank. I installed it myself, it wasn't that hard. We want to do a lot of boon docking in Alaska, so we feel it is worth it. You can pay a little more now, or a little bit every time you plug in.

[RVCrazy]

Originally Posted by Darrens02

RVNut,
You might be surprised, My cost are higher because I live in Alaska, but total I don't think I have more then $1,600 into a 540 watt system that works on 30 volt panels, going into a mppt controller that gives me up to almost 40 amps into my battery bank. I installed it myself, it wasn't that hard. We want to do a lot of boon docking in Alaska, so we feel it is worth it. You can pay a little more now, or a little bit every time you plug in.

Where did you source your parts at? Can you post a list of parts and pieces that you used?

[Darrens02]

I went with CanadianSolar CS6K270 panels. Because of the high volts, I had to go with a mppt controller, I chose Schneider's Conext MPPT 60-150. I am now in the process of adding a battery bank monitor. I can tell you that I am impressed with this setup so far, I have only had cloudy days, and my panels have keep up with my residential fridge for three nights, and 4 days.

[Modmike]

Where did you buy the panel and how much was it?

[Darrens02]

I bought them at Anchorage Renewable Energy, here in Alaska. The service is great, so the price was a little higher. I paid $380. Each

[Modmike]

I can't seem to find an online retailer anywhere. Is that in CAD or USD?

I am in Quebec.

[Darrens02]

That is US dollar. I checked out www.altestore.com they have a lot of information. It is a great place to learn. You could also check www.canadiansolar.com

[HookupAndGo]

Getting ready to pull the trigger on this as well. My issue is figuring out exactly where I want to run the cables on the 351GT. Since I have the residential fridge I don't have the vent stack.

Next thought after that is where to mount the MPPT controller. Since the batteries are in a completely open air area, I have been wondering if it is okay to mount it in that same space.

Need to lay it all out so I can figure out just how much wiring I need to get this all done.

[Cornelius]

HookupAndGo,
Since you don't have a vent due to the residential refrigerator, you will probably want to install a weatherproof junction box on the roof. It can be located above an interior cabinet and the cables can be run down through the cabinet to the basement. I had to do this because my refrigerator is in the slide out. Because I wanted to re-use an existing roof hole from a satellite dish that was removed, I actually used two junction boxes and conduit to protect the 4 gauge cable which is not made for outdoor use. Seal under and around the junction box with Dicor so you don't have any leaks.

If three or more panels are wired in parallel, you will need to install fuses for each panel inside the junction box. If one panel was to develop a short, the output from the remaining 2+ panels could exceed the short circuit rating of the defective panel resulting in a risk of fire.

The charge controller needs to be located as close to, but never in the same area as the batteries, to minimize voltage drop between the controller and the batteries. Most charge controllers are not weatherproof and must be installed in a compartment. You want to use large cable (4 or 6 gauge) from the roof junction box to the controller, and also from the controller to the batteries to minimize voltage drop. Also try to keep all cables as short as possible, again to minimize voltage drop. Voltage drop is an important consideration with solar panels. You want the volts to get to your batteries, not be lost in cable resistance.

Welding cable works well, or simply buy a set of long automotive battery jumper cables and cut off the clamps. From the solar panels to the roof junction box use 10 gauge UL listed 4703 photovoltaic wire. You must use UL 4703 rated wire for connecting the panels, as regular wire will have its insulation crack and break due to exposure from the sun.

Here are some photos of my Georgetown solar install. I installed two 140 watt panels, and then a year later added two 120 watt panels (the 140 watt panels were not available). Last week while boondocking in the Northern Nevada desert they were producing more than 25 amps at 11am.

[Darrens02]

I used a thru roof from Go Power. Since my fridge is not in a slide, I just went behind it from the roof thru the floor to the storage under it. It is just about 4 feet to my batteries, so it all fit. I cut a 50 foot cable in half to go from my panels, to my controller. When it was all done, I think I cut off about 2 feet from the end of it. I have not plugged in my RV in the last month, and my solar has keep up with the fridge running all the time, and keeping the batteries fully charged daily.

[HookupAndGo]

@Cornelius -- Thanks, I like what you had done and seeing the other picture (from the front of the RV) shows more of the lines. That is my issue -- running the power lines.

@Darrens02 -- I will have to look into the possibility of doing the same, drilling through the roof behind the fridge. That part really scares me in that I just hate putting a hole into the ceiling -- and making sure it comes out in a place I can get to. I think the hard part may be working around the fridge.

The next thing is the placement of the controller. I know the battery compartment in the 351 is completely exposed, but I hate having to install the controller in another compartment and loosing some of the space. What I'm thinking of doing is mounting a weatherproof enclosure / box inside the battery area. This would keep things close to the battery as well as leaving my other compartments alone.

Still thinking this through....

[ScottBrownstein]

Originally Posted by HookupAndGo

@Cornelius -- Thanks, I like what you had done and seeing the other picture (from the front of the RV) shows more of the lines. That is my issue -- running the power lines.

@Darrens02 -- I will have to look into the possibility of doing the same, drilling through the roof behind the fridge. That part really scares me in that I just hate putting a hole into the ceiling -- and making sure it comes out in a place I can get to. I think the hard part may be working around the fridge.

The next thing is the placement of the controller. I know the battery compartment in the 351 is completely exposed, but I hate having to install the controller in another compartment and loosing some of the space. What I'm thinking of doing is mounting a weatherproof enclosure / box inside the battery area. This would keep things close to the battery as well as leaving my other compartments alone.

Still thinking this through....

While that will shorten the distance between the controller and the batteries, be careful doing this as depending on the design, some of these controllers put out a lot of heat and an enclosure would potentially prevent them from cooling via heat sinks. If your 351 is the same as my 335, you can put the controller in the compartment just behind the door and route the battery cables out the back which is within 5 feet of the batteries.

[Darrens02]

I agree, I think the heat will shorten the life of your controller. Depending on the style of controller, they are not that big.

[ScottBrownstein]

I know that everybody is really into getting the solar controller close to the batteries. With many designs that is best since the controller doesn't know the voltage it is applying to the batteries, but only knows the voltage that it is putting out on its output lugs. In looking at a 351, you appear to have the same electrical layout as my 335, with the converter and the power cord in the rearmost compartment on the driver's side. The converter has #6 wires from it's DC output to the battery bank, and...it is wired so that the converter will not charge the bank with the disconnect in the off position. Don't know why, but on mine that is the way it is. I designed my solar solution to use the Trimetric system, with a TM and a communicating SC (solar controller.) The voltage that the SC puts out is measured by the Trimetric and relayed via the digital interface between the two units. The TM is on the bulkhead by my stairs (where I can see it from the driver's seat) and it connects to the batteries directly, as well as the shunt and other cables. The solar controller is in the rear power bay and sends it current to the batteries using the same feed that the converter uses (there are spare lugs on my PD 9270) Wires are routed down through the roof, through the fixed storage closet and drawers on the driver's side. In a 351 you can go through the storage on the rear side of the bed. this is a straight through shot down to the power bay. The SC2030 will ignore any losses in the 25 feet of #6 since it will simply up the voltage to get what it wants at the batteries and not at the controller. As a PWM controller, there is always enough voltage to do this coming from the panels. You can wire the temperature sensor to the batteries from there since the length of wire on that interface doesn't matter.

Fact is I will never see more that 25 amps on the solar side and upping the voltage is trivial for the controller. Simple installation and the power bay is big enough to dissipate any heat that it generates. All of the data from the SC is shown on the Trimetric, so you get a solar tax credit on the whole thing.

[HookupAndGo]

So the best way to show this is through pictures.
So, here is my layout. I can put the controller in the storage bay just the other side of the entry way -- hate to do that, it gets pretty hot in there when traveling.


Just to get your bearings, here is the roof of the RV -- still trying to figure out where I want to create a new hole.



And here is a closeup of the battery area. Note that there is lots of airflow. As noted, it would be hard to keep it clean and dry without putting it in some type of container. But, is this much different than a small compartment?