Posted: 2/4/2008 1:19:01 PM EDT
To make a long story short, an older guy, y2k prepper, and good friend of mine died of cancer several months ago. He was like a mentor to me when it comes to prepping (that is until I found this forum  ) as he got me started after hurricane charlie hit us. I was helping his wife clean up around the house and get stuff set up for a garage sale this weekend. She GAVE me the solar panels he had bought for y2k. When he was alive I tried to get him several times to hook them up and see how they work but he never did. They have never been out of the boxes. I got 6 of these bad boys:i108.photobucket.com/albums/n3/trkarl/P1011046.jpg i108.photobucket.com/albums/n3/trkarl/P1011047.jpg They are BP590 90 watt 24 volt modules Now I just need a charge controller and to figure out how to hook them up 
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Sorry about your friend. The panels are gold, and they are for charging 12 VDC batteries. The charger I use is the Outback MPPT because it is extremely efficient and adjusts the load on the panel to optimise the V/A ratio to maximize the output wattage in varying sunlight condx. I wired my 4 80 watt panels in series to reduce wire size needed to connect and for shadowing issues on the trailer. ETA www.outbackpower.com/MX60.htm  |
| EXPY37 that is the controller I am seriously considering buying. From what I understand you can put a higher voltage into it and get a lower voltage out of it for charging. Did you wire them yourself? Do you need special connectors? Right now my battery bank consists of 4 trojan hc L-16s and a ProSine 2.0 inverter/charger. Also did you build a rack for yours or buy one. I've read a bit about panels but never had the money to put into them so I'm not sure how to hook them up yet. |
It's a good controller. It's running here next to me in the desert. I bumped an article I wrote earlier for you: Description of a medium capacity 12V/110VAC electrical system usable for SHTF |
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I finally got my solar project working. Here are some pics: i108.photobucket.com/albums/n3/trkarl/solar1.jpg Here are the panels mounted on 2x4 aluminum. Each set contains 2x90 watt and 1x85 watt panel. I thought they were all 90 watt when I got them. But surprise when I opened the last box and had to take one string of all 90s apart and switch one with an 85 watt panel. The idea is that these are portable and can be easily taken down and stored securely before the zombies come out to pillage at night time. My wife calls it a redneck solar setup. i108.photobucket.com/albums/n3/trkarl/solar2.jpg Here is the breaker box. Each string can be turned on or off individually and the entire output can be turned off with one breaker. I wired the panels with 10awg and ran 6awg (50') to the charge controller. The wire sizing is a bit over kill I know but that is how I do things. The heavier gauge wire in long runs also reduces voltage drop which is critical in low voltage systems. Though the voltage running from the array runs at approx. 40 volts if a panel gets damaged it is already wired for a lower voltage without having to worry about voltage drop. i108.photobucket.com/albums/n3/trkarl/solar4.jpg Here is the Outback MX60 charge controller next to the ProSine inverter control panel. A breaker connects and disconnects the charge controller and the battery bank. i108.photobucket.com/albums/n3/trkarl/solar3.jpg A pic of the entire setup. i108.photobucket.com/albums/n3/trkarl/solar5.jpg A pic of the battery bank. 12v 840ah bank using Trojan L16HC batteries. The inverter is a ProSine 2.0 . |
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If the Prosine doesn't charge this will: Harbor Ft has/had them on sale. Up to 50 amps charge. It looks big, but the bottom area is mostly air. You can use it with a small genny when the sun isn't shuning to chg the batts. ww2.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=93997 
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Each battery is 6 volts at 420 ah capacity and they are wired series/parallel for 12 volts at 840 ah total bank capacity. Amp Hour capacity is normally given at the 20 hour rate. trojanbattery.com/Products/ProductSpec.aspx?Name=L16H |
The ProSine has a 100 amp charger. So i use it to charge from the genny or the grid. |
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Forgive my ignorance, I don't know squat about solar power. With the set up you have established what can you power? I know that is a general question, but what types of things are you supplying power to? If you don't mind me asking, what does a set up like that cost? We are planning on building a new house within the next year and have considered having a solar power set up installed when the house is built. I guess I need to start reading. It looks like a very nice set up also. |
Right now the system would be used to cut genny running to a minimum. It should be able to run the chest freezer and refrigerator and maybe a small fan at night without having to run the genny at all. The panels should be able to produce between 2 to 3 KWhrs of power a day on average depending on the time of year where I live. Today it was real cloudy and sometimes the array would only be putting out 90 watts. But when the sun peaked through it shot right up to 450+ watts. The panels together would be 530 watts but that would be under ideal circumstances. As far as cost goes plan on spending over 6k for that setup if bought new. |
Free Solar |
Exactly. From reading a little on the outback power forums and looking at some efficiency graphs that is the more efficient way to do it with a 12 volt system. Once the array voltage gets too high the charge controller efficiency drops off a little. At least that is what I have read. |
I may try hooking 2 diagonal panel sets of the 4 total on the trailer in a series parallel arrangement to help out the sat dish and airconditioner shadowing problem. |
Good to know, thanks for the answer! |
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I was able to test the system today for the whole day. I left the chest freezer running off the battery bank last night to run it down some. The bank was at 12.5v at 8:30 a.m. this morning when I hooked up the panels and turned them on. I disconnected the system at 6:00 pm that evening. The freezer was connected and running the whole time. It pulls between 4 to 6 amps off the bank when running. By the end of the day the panels had produced 2.7 kwhrs of electricity. It was mostly sunny until late afternoon when some slow moving clouds affected the panel output. The highest voltage the batteries got up to was 14.7v. I think the problem that will be encountered here is undercharging of the bank as Trojan recommends the batteries be charged at 14.8 volts for a 12 volt bank. If it never gets to 14.8 volts it will never get out of the bulk charging stage. EXPY37 how well does your setup keep the batteries charged and what do you do about equalizing them? |
I don't think the MX60 gets to 14.7 volts because I have it programmed lower. I think I did it that way last year thinking it would be "good" for the batteries. I can reset it higher. They don't use much water. The Vector charger goes to about 14.4 IIRC. The output is fixed on the vector. It runs thru the bulk charge at about 30 to 40 amps and then seems to taper to the last 2 stages but I haven't tracked the change-over points vs voltage. One thing, it takes a longer time to get each watt-hour into the battery during the lower current second stage charge vs the bulk charge. Not as efficient. In a SHTF, good thing to know. So, when I run the genny I choose to stop it when it isn't pumping much current in anymore. Maybe at 15 amps, I'll shut the genny down unless I've got the PC and TV or about a 10 to 14 amp load, then I'll let the genny run. I haven't had enough experience with the MX20, in Jan I was getting about .6kw into the batteries at Quartzite, AZ. The panels were flat on the roof, not tilted so the efficiency was way down. Then coming up to northern CA the rear tandem axle support brackets failed from metal fatigue and crappy installation [and an insolvent state of CA that can't repair it's roads  ] and we almost lost the works at 2AM on I-5 @58 MPH, so I've been installing new torsion axles and we're off the road for awhile.ETA RE equalization, I don't worry about it. The batteries are fairly low in cost at Sam's and when they don't seem to have a good capacity I replace them. We do run the Vector charger off 110AC grid from time to time and put a full [Vector] charge in them. |