Sun, we need to have a talk about solar power

[Tahoe]

Our '02 24 RB has solar power. That's a good thing, I think. It seems to work fine, but I want to improve it. First is to replace the Interstate 24 SRM24's with 6V batteries as discussed here in the past. The controller is from '02 and it's a Shell Solar 20-12. I know nothing about controllers, but I'm pretty sure that you can get much better controllers these days. Anyone have knowledge of new controllers with a recommendation? Next is the solar panel itself. I don't know what I have because I can't find a name or data plate on it. It measures 25 3/4 × 62 1/2. My thought was to add a second panel mounted to the roof rack if needed, after upgrading the batteries and possibly the controller. Any solar experts out there?

[bigdipper]

Russ,
I am a big fan of AM Solar. Take a look at what they are offering.
Ralph

[SteveLombardi]

http://www.amazon.com/200W-Mono-Starter ... +panel+kit

Russ,
I'm not an expert but I did successfully put this two panel Renogy setup on my 2012 25ft coach. The panels are mounted front to rear on the sloped portion of the roof on each side of the crank open vent. I ran the wires down the refrigerator vent and put the charge controller under the fridge near the furnace. I then ran the controller output wires through the floor and under the chassis to the battery terminals. I put a 20Amp fuse on the + terminal of the battery connection for safety. This made for a good all-day project.

The system has been working for about a year now and I have seen charging currents as high as 13Amps flowing into the batteries on a sunny day. I find it interesting that even on very cloudy days it will still produce 1 or 2 Amps of charge current.

This might cause a stir with some folks but the panels are mounted to the roof without screw fasteners and instead are attached with 3M VHB (Very High Bond) tape. So far so good and I'm not alone in this method of attachment as some of the experts do it too.

I recently dry camped here in MN at a state park with sunny days and frosty overnight temps. Even with the weakening autumn sun I was able to set the furnace at 65 degrees and it held up well for three nights. The battery voltage would drop to about 12.2 volts (under load) by morning and would then recover during the day to 12.6 Volts. I use two Trojan T105 6Volt batteries in series that I highly recommend.

If would lastly suggest a charge controller with some type of voltage and current display so you know whats happening with the system; and besides, it just fun to witness the extraction of free energy from the sun.

[stevek]

To start with, I would learn about the 2 different kind of Controllers.
PMW vs MPPT. I have a MPPT and have had no problems.
I have 2 standard panels from Home Depot hinged together and portable. 210 watts total.
https://www.youtube.com/watch?v=6W-_pDeNetA

I also purchased 2 each, very thin flexible 100 watt panels from China via Ebay.
They are mounted on a thin sheet of aluminum, that I am experimenting with. Very light.
And seem to work as good as the heavier glass panels.

I also agree. AM solar in OR is a good place to go.
If and when I mount my panels on the roof, I would also use the VHB tape and no drilling.

[Tahoe]

Everyone, thank you! I had been searching but didn't see AM Solar before. Excellent information and if money were no object then lithium batteries would be my choice to start with. I've decided to do my upgrade in stages. First 6V batteries (undetermined which ones yet), then a new controller, followed closely with a second panel, and finally with a 2000 W inverter. Since wiring is in place (except an inverter), I'll hopefully be able to connect to the existing wiring to make it easier. It's clear that upgrading the wiring to a heavier gauge is prefered, but I think I'll go with what is there now and upgrade later if required. I see this as a one year upgrade now, but my gut feeling tells me I'll finish fast after upgrading the controler.

[tomzleapin]

Your panel is probably about 150 watts and the controller is probably a 20 amp.

I have three panels on my coach for a total of 385 watts. One is mounted on the roof rack and two on the side of my coach. The panels on the side are removable and can be set in the sun. I have two Trojan T-125 6 volt golf cart batteries. The T-105 is the most common 6 volt battery, but the T-125 is the same size and is more amp-hours.

I would suggest upgrading to two 6 volt batteries and adding an additional solar panel. Your existing controller should work fine.

Here's a couple links to sites with a wealth of info:
Jack Mayer - RV Electrical and Solar
HandyBob - The RV BATTERY CHARGING PUZZLE




Slide show of my installation

[Rob]

Note for TAHOE,

I converted to 6 volt Trojan batteries on my 2003 24RB about a year ago. Easy to do and worked out well.
Rob and Joan
2003 24RB
Tuolumne, CA

[Tahoe]

After investigating all the info I think AM Solar is a great source. I also discovered with all the research, that BF did a sub-par installation as far as wiring, and the controller is just so so. Of course it was 13 years ago and solar installations today are so much better. The only thing I'm keeping in the upgrade is the solar panel. Unfortunately the upgrade needs to wait until Spring as snow is forecast for Monday, and the BF goes into storage Sat. I'll do my best to document the upgrade and post next year the results with pictures.

[bcope01]

Russ, I was not aware BF did a factory install of your solar panel. What was inferior about the wiring?

Bill

[Tahoe]

Russ, I was not aware BF did a factory install of your solar panel. What was inferior about the wiring?

Bill

I purchased from the original owner who bought it with the solar package.

Basically all they did is run 12 ga to the controller which is a shunt type. From the controller they ran 12 ga for about a foot and tied into the 10 ga wire that feeds the heater fan. That's it! It works, but very inefficient.

So I'll replace the controller with an MPPT, add one more solar panel, run 6 ga to and from the controller, run from the controller directly to the batteries with circuit breaker, switch, etc.

I'm not criticizing BF since I don't know the whole story since the wiring does work, but is not what would be done today. Kind of a supprise, but with all the info now available, and knowing their quality, I can't imagine it would be done that way today. Not a problem for me because I enjoy working on and improving things. Learning about solar is certainly fun.

[stevek]

Jack Mayer has a good write up on wiring, wire size and voltage drop.
http://www.jackdanmayer.com/Wiring.html

BF has done recent Solar installations.
One member had his new 2011 BF modified with Solar that he got from AM Solar.
Hopefully he will chime in.
His Born Free is for sale.
This was taken from his ad.
"Coach electrical system designed by AM Solar and installed by Born Free,
includes 300W roof top solar panels, sophisticated charge controller including battery
temperature monitoring, 440 AH Lifeline AGM batteries, 2000W Cotek heavy duty inverter,
Trimetric instrumentation for precise battery condition determination."

[oliverpsmile]

Looking for a reasoning for 2000 Watts inverter and associated heavy duty wiring on board.

A 2000 Watts inverter at full load would drain the batteries within an HOUR.
300 -400 watts solar would not fully recover the batteries in a day of sun and clouds, especially with stationary (not following the sun) panels.
Then the generator would be needed for several hours.

Therefore, if someone needs 2000 Watts of energy, isn't it more cost effective to start the generator for an HOUR?

[Tahoe]

Looking for a reasoning for 2000 Watts inverter and associated heavy duty wiring on board.

A 2000 Watts inverter at full load would drain the batteries within an HOUR.
300 -400 watts solar would not fully recover the batteries in a day of sun and clouds, especially with stationary (not following the sun) panels.
Then the generator would be needed for several hours.

Therefore, if someone needs 2000 Watts of energy, isn't it more cost effective to start the generator for an HOUR?

I hear you. I struggle with it a well, so if I do an inverter it will be the last thing I do. But, when using the inverter it will power the microwave, coffee maker, toaster, and TV, etc. This last season we were in campgrounds without hook ups that had very restrictive generator hours for good reasons. If I wanted to make coffee at 6 am, or use the microwave after 8 pm I was out of luck. One campground had generator hours from 8 to 9, 12 to 1, and 5 to 7 only. I understand the restrictions, but it isn't always convenient. I wouldn't use the inverter long enough to drain the batteries, but it would be nice to watch a movie, make some popcorn, etc off hours. In the last 20 years with our Airstream and now BF we have only camped with hookups about 10% of the time, so battery power has been great. The Airstream didn't have a TV or microwave so it was pretty easy. All we needed it for was our radio and lights. We had a portable generator for coffee, toaster, and to recharge the batteries. We still had restictions though. Being older and hopefully wiser I want the freedom to use power when I want without disturbing the other campers. Inverters aren't for everyone and because of he cost it might not be for me, but it's on my wish list. FYI, we do have a small 400W modified sine wave converter we use for the TV and it works fine to watch a movie, etc, but it is not quite, so we've isolated it as best we can and it's not bothersome. We can't use it to make coffee, toast, etc because it's just not powerful enough.

[oliverpsmile]

Well, luxury comes with a price
5 minutes for popcorn is ~ 10% drain on the battery, Coffee may be cheaper.

I may be niggardly, but I make popcorn and coffee on the gas stove.

I use 300 Watts pure sine wave inverter. It powers all outlets through a transfer relay.

[bigdipper]

This is second try since local wi-fi kicked me off. Sorry if it ends up being a duplicate.
We have 2000W inverter, 300 AMP solar and 440 AH AGM batteries. We dry camp 2/3 of the time, typically 1-3 days at a spot using micro 10-20 minutes per day(no convection), coffee maker, and DTV maybe 5-6 hours per day. Never have batteries gotten below half full, never have I run the V10 to charge, and most days batteries are back to 100% by evening. Biggest energy hog turns out to be the furnace. Our system was designed for this use pattern and all has worked to perfection.
Ralph