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Post by gotsunshine on Nov 7, 2016 19:52:11 GMT -8
I am just about ready to start putting together my new purchased pieces. i do not understand if my four 100 w Renogy panels should be in series or in parallel. Not only that but I do not know if or why I want 12v or 24v. I am going to be using a Renogy Tracer 4210 40 Amp MPPT Charge Controller 12/24V 100VDC, four batteries, a Power Bright PW6000-12 inverter and a Tracer Meter MT-50 for Commander Charge Controller with LCD Display, as a permanent setup. My purpose is especially for emergency use and to cut down some on household electric cost. My two questions are 1) use either series or parallel array 2) why is there a choice between 12v and 24v? I am stalled out until I get some help.
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Post by jsb2000 on Nov 8, 2016 5:42:04 GMT -8
Basically, the choice of whether to go with a 12V or 24V system boils down to three factors: Wiring (size, distance), solar panel placement (will individual panels get shaded), and what you've already purchased/plan to power (have you already purchased something that runs on one of the possible voltage). Now for the details:
Generally speaking, the higher in voltage you go, the thinner the wire you have to use. Also, losses are less for longer runs at higher voltages. So, if your panels are going to be located at a distant point, 24 or 48V trumps 12V.
If one of your panels gets shaded in a parallel configuration, you only lose the power of that panel. If one of your panels gets shaded in a series configuration, you lose the power from them all.
If you've already purchased a 12V device (in your case, the Power Bright PW6000-12 inverter), then I'd stick with a 12VDC (parallel) configuration. Do you plan on running other devices that run on 12VDC or is the rest of your system already at 24VDC? If the latter, then you may want to return the Power Bright and select a model that runs at 24VDC.
My personal opinion is to go with 12VDC (parallel) for the entire setup (batteries and panels) unless your panels/batteries are going to be located a good distance from each other.
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Post by rabird on Nov 8, 2016 7:48:27 GMT -8
There are 2 sides of the controller and since you have an MPPT, you can series the panels into the controller and the output to the batts can be '12v' or '24v'. Series advantage is 1/2 current for 2 panels in series compared to 2 parallel. Less current = less voltage drop for the same size feed wires to the controller. Additionally, look at the controller manual (last few pages) to compare controller efficiency at various input/output voltages.
With 4 panels you could have 2 strings of 2 panels, ie 2 x 2 panels in series, paralleled to the controller, this would give you 1/2 the current of 4 in parallel. Each string of 2 in series = 11A compared to 4 in parallel @ 22A.
4 in series would be near the 100v input limit (Voc~22vx4 = 88v)
I suggest sticking with 12v batt configuration (4 12v in parallel and balanced, 4 6v in series/parallel configuration).
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Post by gotsunshine on Nov 9, 2016 19:22:11 GMT -8
Thank you so very much for your wisdom and time to help me. Ido not know what balanced battery means.
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Post by rabird on Nov 10, 2016 5:43:08 GMT -8
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Post by prepper on Dec 26, 2016 14:49:31 GMT -8
There are 2 sides of the controller and since you have an MPPT, you can series the panels into the controller and the output to the batts can be '12v' or '24v'. Series advantage is 1/2 current for 2 panels in series compared to 2 parallel. Less current = less voltage drop for the same size feed wires to the controller. Additionally, look at the controller manual (last few pages) to compare controller efficiency at various input/output voltages. With 4 panels you could have 2 strings of 2 panels, ie 2 x 2 panels in series, paralleled to the controller, this would give you 1/2 the current of 4 in parallel. Each string of 2 in series = 11A compared to 4 in parallel @ 22A. 4 in series would be near the 100v input limit (Voc~22vx4 = 88v) I suggest sticking with 12v batt configuration (4 12v in parallel and balanced, 4 6v in series/parallel configuration). Can you provide a diagram of how to wire 4 100w panels t have 2 strings of 2 panels, ie 2 x 2panels in series, paralleled to the controller? My batteries are 12 volt output into a 12v volt inverter. Bad part is panels to controller is appx 80 ft. with a 40a mppt controller. |
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Post by rabird on Dec 26, 2016 18:20:40 GMT -8
if ya connect the + from one panel to the - of the another panel, that is 2 panels in series. The remaining - and + from the 2 panels goes to the controller. Do the same for another pair and ya have 2 parallel strings of 2 ea in series.  |
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