Honestly, you should have an attitude adjustment! If you actually plug the specs into the sizing calculator, the calculator itself states "Array power (Wattage) excessive". It's not my verbage, it's the verbage of the calculator itself. I CAN add you know. Four panels in series is 157V, which I think maybe might be less than 200V. When you input the number however as two 2-panel strings, the calculator gives you a green OK.
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There is someone you should not listen too because they have no idea WTF they are talking about or even what they just said.
Has nothing what so ever to do with wattage. The Wattage of the 4 panels is exactly the same if in all four panels are in parallel or series. The difference is the VOLTAGE is too high with all panels in series, and with 4 panels you only have 3 option. All in parallel which is the last thing you want with a MPPT Controller, All in Series which is what you want if it does not exceed Voc input of the controller, and Series/Parallel in 2 x 2.Leave a comment:
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The answer is both. I plugged your panel's specs into the sizing calculator, and it doesn't like all four of your panels in series; wattage is too high. It does like two parallel strings of two panels in series. Wire it up that way with your MPPT controller and you're good to go.Leave a comment:
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Sunking,
Thank you for the reply. Its a little convoluted, but I think what you're saying is to wire them in series.
"Quit listening to people who do not know WTF they are talking about." I haven't listened to anyone, yet, so I cannot quit. What I've done is a lot of research and have asked a lot of questions. When things contradict I continue to ask questions. This is a small system that I have built myself, to learn as I go. How am I supposed to magically know who knows WTF they are talking about? If I knew who knew WTF they were talking about, after all the research I mentioned doing, I wouldn't be here asking more questions, would I?
“If you do not know WTF you are doing, you buy very expensive Battery Panels and dirt cheap PWM controller “
I don't see how this applies. I do not have a dirt cheap PWM controller. I think what you're doing is giving an example of someone that has done something I'm not doing. Also you're giving examples of the difference between PWM and MPPT, which I'm aware of. You're advocating an MPPT controller over a PWM; we agree, already. As you can see in my post I already own an MPPT controller. This is an entire paragraph about PWM expense vs. MPPT expense; if there is relevance here I don't see it.
“life is simple and efficient running high voltage on your panels up to 60 to 200 volts . Unlike what you will be doing operating at 12 volts. “
I think what you're saying here is that my life (solar system) isn't simple and efficient because I'm running 12V. Running at higher volts would require me to step everything back down to use almost every piece of DC equipment I own on a system used to charge flashlights and run a couple of appliances you'd see plugged into a car. I didn't arbitrarily choose to keep the batteries at 12V. I will add to my knowledge base that having a 12V system is neither simple, nor efficient and mention that to others. I wonder if anyone will tell me to stop listening to people that don't know WTF they are talking about.
This is what I consider simple. A few decent panels (which I have), run to an MPPT charge controller (which I have), hooked to a battery bank that runs at the V for everything I want to run or charge. The question I was asking was whether to run them in series or parallel.Leave a comment:
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Quit listening to people who do not know WTF they are talking about. It is all abou twhat kind of panels and controller you use.
If you do not know WTF you are doing, you buy very expensive Battery Panels and dirt cheap PWM controller. When you go that route you must parallel the panels not to exceed 18 volts. Battery Panels are 18 volts. Then they cheap out and buy a cheap PWM controller, so they turn their 100 watt panels into 65 watt panels. It takes a 300 watt PWM system to equal a 200 watt MPPT system. A 300 watt PWM system will cost you $600 to $800, you have to wire all th epanels in parallel requiring combiners, fuses and extra large wire to handle that low volt and high current. Up around a $1000 because they did not know WTF they were doing.
Smart Money buys dirt cheap higher voltage higher wattage grid tied panels and a good MPPT CONTROLLER. Smart Money wire as many panels in series to get voltage up and current down. A 200 watt MPPT system you spend $$200 on panels, and $200 on a 15 amp MPPT controller for a total of $400 to $500, less than a 300 watt PWM system and they do the same thing. Additionally with the panels wired in series much smaller wire over longer distances, id Two strings or less no combiners or fuses needed., life is simple and efficient running high voltage on your panels up to 60 to 200 volts . Unlike what you will be doing operating at 12 volts.Leave a comment:
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Conflicting advice on series vs. parallel for charging 12v Bank. Please advise.
I've researched my eyes out and have called a few people, but I seem to get a lot of conflicting information.
My system is small and doesn't move. All panels get ample light at the same time and are never shaded. My panels are less than thirty feet from the charge controller and the batteries are less than five feet from it.
This system is for emergency power and charging. Everything thing I have is 12V DC, or well within the ability of running off my small inverter (which is almost never used). I estimate that if I were to hook up everything I could think I'd ever need at the same time, I would use 1.5 Kwh over 24 hours, most of that being a slow constant draw.
The batteries (stats below) I have are wired in parallel staying at 12V. I do not wish to go to 24V.
Right now I have one 300 Watt panel that is doing OK. I recently got a great deal on four 280 watt panels (stats below) and want to hook them up to my system (removing the old panel) and add more batteries to run a DC Fridge and Freezer.
Now for the problem:
Some people are telling me to put the panels in parallel and some are telling me to wire them in series. The parallel-minded people are saying that the panels have enough volts already and this would bring you to a higher amp rating the batteries can definitely handle. Thus charging faster/better.
The series-mined people are saying that with an MPPT controller you always want to wire in series as along as the charge controller (stats below) can handle it. Maxing the Volts out while staying inside the battery's amp charging rate. Thus charging faster/better.
Of course I want to charge as fast as possible and do what is best to prolong the life of the batteries.
Could you please tell me what configuration you would put these panels. Parallel, series, or 2X2 in series and then each pair linked in parallel? Does it even matter? Other than wire sizing, is there an advantage to either setup?
Personally I'm leaning toward all parallel. The Midnite Solar string sizer says that all 4 panels in series would be excessive. Others say it can handle it.
Thank you.
Here is my equipment:
(6) SLR124 VmaxTank Batteries in parallel AGM
Nominal Voltage 12V
20Hr Capacity 125AH
RC (Min) 260
Energy (kWH) 1.7
Charging Current 8A-35A
Charging Voltage 14.4-14.9V
Float Voltage 13.5V-13.8V
(4) STP280S-20/Wew Solar Panels
Max Power 280W
VMP 31.5V
Imp 8.89A
VOC 39.4V
Max System V 1000V
Max Series Fuse 20a
(1) Midnite Classic 200 Lite Charge Controller
Operating Volts In: 200VDC
Max Hyper VOC 200+battery
Battery Charge Volts 12-93
Absolute Curent Output 74a at 12V Battery
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