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I have a 24 volt panel 165 watt and 2 12 volt 140 watt . I would like to know if I could series the 2 12 volt 140 watt to make it 24 volt then parallel the 2 140 watt in series to the one 165 watt 24 volt ?
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Hello Winchester0080 and welcome to Solar Panel Talk
The problem with mixing panels is that first off they aren't really 12v and 24v. Second if the Voltage and Current specs or too far apart then usually the panel with the poorest spec brings down the panel with the best spec.
The 12volt usually have a rating of Vmp ~ 17.5 to 18.5vdc and Voc ~ 22 to 23vdc
The 24volt usually have a rating of Vmp ~ 36vdc and Voc ~ 44.5vdc
It may be possible to wire 2 of the "12v" panels in series to equal the Vmp of the "24volt" panel.
The panel wattage is calculated by multiplying the Vmp x Imp which varies based on a number of properties of the cells.
If those Imp ratings of the different panels are too far apart the lower one will hurt the higher one since you have wired those panels in parallel.
So depending on the actual specs of those 140 watt & 165 watt panels you may be able to do what you want and then again maybe not. -
The 140 watt panels Vmp = 18.1 Imp - 7.94 / The 165 watt 24 volt panel is Vmp - 34.6 Imp - 4.77 I was hoping to increase the ampsComment
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So if you wire 2 of those 140w panels in series you will get 280watts or 36.2v @ 7.94amps.
When you wire a 165w panel in parallel to the first pair you then have a system with ~ 35.4vdc but the amps will be somewhere between 7.94 and 4.77 and all together you will not really generate 445 watts even though the nameplate of your 3 panels add up to that amount.
Now I might be wrong on my estimates and calculations but I don't believe the way you want to wire them will get you an increase of amps.
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Seems to me when you parallel the series wired 12 volt panels with the single 24 volt panel you would end up with something like 12.71 amps at something like 35.4 volts.2.2kw Suntech mono, Classic 200, NEW Trace SW4024Comment
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OK thanks for the information SunEagle Ill just wait until I can buy 2 more 140 watt panels that way they are all the same .Comment
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Your proposed panel configuration will be fine. There will be a slight voltage drop. I would go ahead and wire it up and test with a meter. Be careful not to measure the amps lead to lead as it could be over 10 amps and fry the meter.3.6 kw PV, Classic 150, Radian GS4048A, LFP 195AComment
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We did a series of videos demonstrating wiring mismatched solar panels. There's a playlist here. https://www.youtube.com/playlist?lis...nDgeEyFKDy2Tpz The scenario you would be seeing is pretty much same voltage, different current.Solar Queen
altE StoreComment
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I usually shine the brightest sometime between my morning coffee and my afternoon nap, We must be in
different time zones. lol2.2kw Suntech mono, Classic 200, NEW Trace SW4024Comment
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So I hooked them up . I waited to long sun going down but I was able to get a Voltage reading on the open leads 40.6 volts . Its to late to get a amp reading .Comment
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The 40+ volt reading would be the open circuit voltage. When you put a load on them you should get the Vmp discussed earlier.2.2kw Suntech mono, Classic 200, NEW Trace SW4024Comment
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I just wanted to thank everyone for your help. I installed a thermodyne 130 amp watt meter logger so I could see results of my series parallel. I live in northern California and it started out sunny today but now is over cast but for amps the highest it registered was 9.239 amps which is more than 7 so improvement. I have 4 165 watt panels on one controller series parallel and these 3 hooked up to a separate controller . I have 8 / 55 amp hour batteries hooked up series 24 volt and parallel . I am using a Power Bright 2300 watt 24 volt power inverter. So this is my beginner solar power set up Im using to run this computer for now.Comment
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