Getting ready for solar

Topic: Getting ready for solar (Read 1847 times) previous topic - next topic

Getting ready for solar

September 17, 2017, 01:50:19 pm

Just bought 4 of these before I go any further is there any issues I need to know before buying a controller.

Re: Getting ready for solar

Reply #1 – September 17, 2017, 02:42:29 pm

MPPT and if wiring in series, or series/parallel, 150 volt 80 amp or over.

Re: Getting ready for solar

Reply #2 – September 17, 2017, 03:20:49 pm

I'll add to the above comment: spend the extra for a good quality MPPT controller. I first bought a less expensive unit that the manufacturer swore was as good as all of the "overpriced" brands. I ended up having to buy a GOOD controller and spent far more money than I should have, with the cost of the first one. Morningstar is a quality brand, with a wide selection of models for whatever needs you have. There are other quality brands, as well, I just happened to have good luck with Morningstar. Get batteries that have high Amp Hour ratings. If you settle for average capacity, you will find yourself looking for shore power or running your generator often. The whole solar exercise would be pointless.
If you are having professionals design and install your system, these two points are still valid. If you plan to design your own system, make very sure that you spend a LOT of time researching before you ever spend a dime on equipment.
This forum is full of folks who have gone both routes, and by using the search feature, you will find your research efforts will be a whole lot easier.

Re: Getting ready for solar

Reply #3 – September 17, 2017, 04:17:41 pm

Didn't someone on this forum recently post they have an extra Morningstar MPPT 65 amp unit for sale?

We think this a a great controller, and it has an Ethernet connection for easy to programming from a computer.

Re: Getting ready for solar

Reply #4 – September 17, 2017, 04:32:53 pm

With almost 1200 watts he will need a minimum of 80 amps in one controller or use several smaller ones. As said, best to buy a good quality one, I have used Morningstar, Outback, Midnite Solar and Victron with good results.

Re: Getting ready for solar

Reply #5 – September 17, 2017, 04:36:53 pm

I have 3 Lifeline 8D 250 AH AGM's and don't plan on adding any more. I also want to keep using my Xantex SW 3012. I will do the install myself and so far am planning to buy the Midnight Solar Classic 150 MPPT I have book marked for the last year all the information I could find on the forum, but this is not my field of experience so a lot of searching and watching U tube videos is my next step.

Re: Getting ready for solar

Reply #6 – September 17, 2017, 04:44:22 pm

When I started buying parts last year, I bought a 65 amp controller expecting it to be plug-n-play. But after buying the Suniva 285W panels, it wouldn't work. I went to the Morningstar website and used their solar calculator and found I needed the 80amp MPPT. It's worked great for the last 9 months. I initially got worried when I went over 100 ah in a day, but have no worries taking it to 180 ah. It may take 2 days to get back to "0", but batteries and controller are doing a great job.

Re: Getting ready for solar

Reply #7 – September 17, 2017, 05:45:19 pm

I have a room full of pretty blue Victron products that I'm still in the process of "getting ready" to hook up. In the pile is a 85amp solar controller. I'm sure they will work fine in the mean time they sure look nice.

Re: Getting ready for solar

Reply #8 – September 17, 2017, 06:03:22 pm

I won't be starting the installation until after Christmas so plenty of time to collect "pretty parts" also. But once I get my teeth into something I don't stop until finished.

Re: Getting ready for solar

Reply #9 – September 17, 2017, 07:01:43 pm

Make sure you use the right wire size and circuit breakers.

Re: Getting ready for solar

Reply #10 – September 17, 2017, 07:12:10 pm

Quote from: Dakota Slim – September 17, 2017, 07:01:43 pm

Make sure you use the right wire size and circuit breakers.

Pierce has a post with sizes and part numbers along with a good description on DIY.

Re: Getting ready for solar

Reply #11 – September 17, 2017, 08:01:18 pm

My Midnite Class 150 is conservatively rated for 96 amps but I think you can put at least 1500 watts of panels up top but should limit the voltage to about 10% less than the 150 volt rating. For about $500 delivered, I consider it the best on the market. It's provided trouble free service for the years we have had it installed.

I typically see a winter maximum of about 600-700 watts from our 1140 watt potential. This is with a flat installation. Summer, especially in the lower U.S. will come closer to the panel rating. Unless you are running a residential fridge, four large commercial panels should be enough to have plenty of lighting and 4K TVs plus run a latte machine and microwave in the morning without ever having to start the generator.

If you can't find my post with the sources/parts numbers/prices, please PM and I will email it.

Pierce

Re: Getting ready for solar

Reply #12 – September 18, 2017, 03:12:50 am

Quote from: craneman – September 17, 2017, 06:03:22 pm

I won't be starting the installation until after Christmas so plenty of time to collect "pretty parts" also. But once I get my teeth into something I don't stop until finished.

I have been slowly plugging away at the project. I made a battery compartment for 6- L16 AGM Lifelines. I built a battery platform that is supported by the basement floor and the ceiling above to help split or take some load off the floor. I will actually start installing "pretty stuff" Monday after I install the battery bank. I have the aluminum to mount the 4- 300watt panels and will glue them up this week also. I should achieve a fast snail like pace from now on.

Allen at Bay Marine (the BEST) told me that I would probably never see over 85 amps and if I did the controller would limit output to 85amps, so a bigger solar controller was really not needed and no damage would ever result if more than 85amps came in.
I move like a snail because I'm completely out of my element with this install. I rely on people like Allen for there advice and go with what they recommend. I move slow because I have to rely on common sense when learning as I go.

Advice from Roger Engdahl and Roger Fleming have been a huge help.

Re: Getting ready for solar

Reply #13 – September 18, 2017, 07:44:56 am

I recommend wiring in parallel, since it is a 12 volt system. The MPPT will have better efficiency converting your 31 Volt panels to 14 Volts.

Re: Getting ready for solar

Reply #14 – September 18, 2017, 09:13:18 am

Quote from: Tim – September 18, 2017, 07:44:56 am

I recommend wiring in parallel, since it is a 12 volt system. The MPPT will have better efficiency converting your 31 Volt panels to 14 Volts.

That might happen, right now I am trying to figure out wire sizes for the 2 in parallel at 72 volts vs. all in parallel at 31 volts. Also I have to figure out how to get the wires off the roof. The coach came with residential refrigerator and the old vent was fiber glassed closed.

Re: Getting ready for solar

Reply #15 – September 18, 2017, 09:54:13 am

Quote from: craneman – September 18, 2017, 09:13:18 am

That might happen, right now I am trying to figure out wire sizes for the 2 in parallel at 72 volts vs. all in parallel at 31 volts. Also I have to figure out how to get the wires off the roof. The coach came with residential refrigerator and the old vent was fiber glassed closed.

A small loss of efficiency when running higher voltages, but a lot easier to run #10 than #2 wire, Grid tie systems [selling solar power back to the electric company directly] often send 600 volts through many panels.
MPPT Charge Controllers: Page 2 of 2 | Home Power Magazine

Re: Getting ready for solar

Reply #16 – September 18, 2017, 10:26:46 am

12V 18Ah CB19-12 Sealed Lead Acid AGM Rechargeable Deep Cycle Battery FREE...
I use 3 of these in one of the race cars to eliminate the alternator . They test @ 22-23 AH. Would 20 of them make any sense for a Solar bank?

Re: Getting ready for solar

Reply #17 – September 18, 2017, 10:46:07 am

Quote from: Protech Racing – September 18, 2017, 10:26:46 am

12V 18Ah CB19-12 Sealed Lead Acid AGM Rechargeable Deep Cycle Battery FREE...
I use 3 of these in one of the race cars to eliminate the alternator . They test @ 22-23 AH. Would 20 of them make any sense for a Solar bank?

Price wise batteries a good deal, but you would spend a lot on wire and connectors

Re: Getting ready for solar

Reply #18 – September 18, 2017, 11:11:17 am

Lots of ways to do this.

Be sure to use a big enough controller and all of the appropriate fuses or CB. Add a big OFF switch if you want. You need appropriate fuses atbthe battery connection end as well.

I connected the panels in parallel, I didn't want a combiner box on the roof, cables mostly run under panels or along side AC units, easy to secure and they are out of the way.

With four panels you will have 8 wires. A couple of these, 3/4" hole, 3M 4000 UV and stainless steel screws and you are set.

Amazon.com: Winegard CE4000 Cable Entry Plate: Automotive

Running all the cables down to a place where you can fuse each panel separately and then connect the controller is much easier and more servicable that combining them on the roof.

I used a Victron MPPT controller. Flawless. There are other choices as well.

Think this through well, where will all of the parts and wires go? Having a good plan makes the doing easier. If you are not sure, ask more questions.

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Re: Getting ready for solar

Reply #19 – September 18, 2017, 11:38:57 am

Quote from: craneman – September 18, 2017, 09:13:18 am

That might happen, right now I am trying to figure out wire sizes for the 2 in parallel at 72 volts vs. all in parallel at 31 volts. Also I have to figure out how to get the wires off the roof. The coach came with residential refrigerator and the old vent was fiber glassed closed.

Super easy to just go to solar panel wiring | eBay and order up some #10 for either one of your designs. I bought a gray plastic electrical box with two inlets for my electrical flex conduit and the third opening is larger so I just drilled the roof above my compartment I used for the controller. Use a stud finder to make sure the hole clears any aluminum frame members. The solar wires are very easy to cut to length and put the connectors on. So easy that I laughed when I did it the first time. You then connect the positive of one panel to the negative of the other one with the quick connect couplers and feed the TWO remaining wires (one from each panel) with the 72 volts through the flex conduit, push the conduit through the box on the roof after feeding the wires down. I used Adel clamps to secure the conduit to the roof under the panels. I used GE Silicone II to seal all holes through the roof. Use a label machine on the wires so you always know where each one came from.

The advantage of the series wiring is you will have less loss (not much either way) and only two wires through the roof so easier to keep neat and wire to a bus and then to the controller. I used large welding cables to essentially bring the battery to the controller. Bringing the big cables up to another bus where I made a short run to the controller connectors with smaller wires. I ran everything through two breakers for the panels and two breakers on the battery side. I also put in a fuseable link where the big cables connect to the main bus down in the compartment. I used backerboard everywhere I could to reduce any possibility of fire. Here is the link to all the photos: https://goo.gl/photos/9KGwM2Zk28f5s4NW8 Even if you only bring two wires from one conduit down, it's nice to have a electrical box on the roof with room for two for future expansion and also a removeable lid so you can feed the wires down. Our installation is slightly more complex as I chose to incorporate the breakers above the Midnite controller.

So, looking at the photos, why didn't I make a continuous run with the big cables rather than putting in a small box? My cables were not long enough plus I wanted to tap into the 12V for a couple of audio amplifiers.

Chuck, I will be at the SB Airport fire station until sometime on Sunday if you want to drive up take a look. I have the tarp off getting ready for the trip so I can take photos of any/all(s) part of the installation. Will email a diagram/schematic in a couple of hours.

You share the same love of the June Lake area that we do. Never crowded and no need ever for AC. Photos from Oct, 2011: June Lake 2011 - Google Photos

Pierce

Re: Getting ready for solar

Reply #20 – September 18, 2017, 12:17:19 pm

Place panels where they won't get shadows from roof top equipment. Some panels will not work if one cell is in a shadow

Wantabe

Re: Getting ready for solar

Reply #21 – September 18, 2017, 12:44:01 pm

Ours still get good output even if partially shaded. Naturally, best output in full sun and especially if the sun is directly overhead. We will have almost full voltage from the panels but no amps before the sun is even up. Amazing. This is the reason the controller manufacture likes to keep the voltage 10 percent below the rated controller specs. Solar panel voltage is rated at 77 F degrees. Below that, the voltage is HIGHER and if in freezing temperatures, the voltage can be much higher than the rating. Some controllers either will not turn on until the voltage drops or in some cases, the high voltage will severely damage the controller. All things to consider when selecting the voltage you bring into the controller.

Pierce

Re: Getting ready for solar

Reply #22 – September 18, 2017, 01:05:57 pm

Does anyone know for sure or will anyone take the time to contact a or their battery maker and ask if the slow charging that solar induces versus the inverter/charger or alternator method affects the batteries life?

I understand it's a necessary evil but the info ahead of time might offer alternatives like equalizing lifeline AGM's more or less often.

Gels cannot be equalized. Non lifeline AGM's cannot be equalized.

The 20% of capacity charge rate mentioned I have seen used by most, if not all, battery makers and was built in our coaches systems.

Unknown how or if it will affect the cycle life or capacity.

Any actual info around?

There was an alternate slow charge method I think on lifelines website.

Like I said a necessary evil. Maybe. Just what exactly may we be doing and is there anything to worry about long term.

The MK engineer mentioned many ten to twelve year life oem gel installations in Foretravel already and the factory's latest mods might double their life.

At $2k+ for a battery system the info may or may not be needed

Re: Getting ready for solar

Reply #23 – September 18, 2017, 01:17:23 pm

Craneman, Consider the Magnum PT-100 controller. 100A 200V. If my math is right, will handle your 4 panels in series so only 2 wires to run.

PT-100 MPPT Charge Controller | Magnum Dimensions

Re: Getting ready for solar

Reply #24 – September 18, 2017, 02:44:29 pm

Craneman, Consider the Magnum PT-100 controller. 100A 200V. If my math is right, will handle your 4 panels in series so only 2 wires to run.

PT-100 MPPT Charge Controller | Magnum Dimensions
[/quote]
The new Magnum looks good, has almost the exact same specs as the Midnite Classic 150 but seems priced about $200 more at $590 vs $800. The display is very limited compared to the Midnite plus it does not seem to be internet capable. Magnum up until lately worked with Midnite on quite a few projects. Located close to each other.

MPPT Solar Charge Controllers | Easily Compare The Best Brands

Midnite Classic 150
12V to 72V Nominal Battery Charging
Built-in Ground Fault and Arc Fault Protection
Internet Ready Via Ethernet
Additional Communication Via RS232 and USB
20 Megabytes of Data Logging Storage
Remote Monitoring Via Internet
Supports up to 2 displays (up to 1000 feet away)
Comes With a Battery Temperature Sensor
5 Year Manufacturer's Warranty
Made In The USA!

I like to review all the new models and have no problem moving on to something better when it comes along. Just has to provide better specs, warranty, options, and price.

Pierce

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