Series or parallel my panels

[Sportzfann]

I have 4 325 w jinco panels on my rv just installed and I’m getting ready to wire them.
the panel specs are 33.6 vmp and 9.6 Imp. I have a Victron 150/45 charge controller.
i wanted to run in parallel, but i will be real close to max amps of controller
If I run in series, I’m worried I will be to close to max volts.
would 2 pairs of panels in series i work if I parallel after ?
I was thinking this would work 67.2V and 19.36A to the controller?
Thanks,Sportz

 

[sunshine_eggo]

You use Voc for max voltage. 4S will over-volt @ 164.4V

Typically 3S max 60 cell panels on a 150V controller, so 2S2P is your maximum series option with 4 panels.

If shading/partial shading is a concern, 4P may be the winner for 12V or 24V battery.

 

[Sportzfann]

You use Voc for max voltage. 4S will over-volt @ 164.4V

Typically 3S max 60 cell panels on a 150V controller, so 2S2P is your maximum series option with 4 panels.

If shading/partial shading is a concern, 4P may be the winner for 12V or 24V battery.

Will the current levels be a problem with these all in parallel 10.2 A ea. x4 40.8 total?
I do have. 400ah bank 12V lifpo
Is one way wiring better than the other? Shading/ max power etc? Thanks ?

 

[sunshine_eggo]

Will the current levels be a problem with these all in parallel 10.2 A ea. x4 40.8 total?
I do have. 400ah bank 12V lifpo
Is one way wiring better than the other? Shading/ max power etc? Thanks ?

Parallel is always better any time shading is an issue.

40A will be too high for MC4 parallel connectors, but a 4 into 1 combiner box should work. 2S2P would be fine with MC4 parallel connectors.

 

[Sportzfann]

Sunshine, I will need to look at getting a couple small buss bars or 2 / 4 into 1 mc4 adapters. I might have a couple roof vents that could partially shade my panels. I have a 8x8x6 jbox on the roof with 8/2 pv cable and 3/4” flex down to my charge controller. I guess I can wire it 2s 2p until I get the 4/1 adapters, probably not much of a drop in efficiency.
I appreciate the advice ?

 

[sunshine_eggo]

Sunshine, I will need to look at getting a couple small buss bars or 2 / 4 into 1 mc4 adapters. I might have a couple roof vents that could partially shade my panels. I have a 8x8x6 jbox on the roof with 8/2 pv cable and 3/4” flex down to my charge controller. I guess I can wire it 2s 2p until I get the 4/1 adapters, probably not much of a drop in efficiency.
I appreciate the advice ?

That's what I meant... 4-1 MC4 adapters can't carry the 40A. They are only rated for 30A. You MIGHT be able to find some rated for 50A, but the legitimacy should be reviewed. there are combiner boxes specifically for combining higher current arrays/to heavier gauge output.

I am not endorsing this. I am providing an example:

Amazon.com

I might choose it in your situation.

 

[Sportzfann]

You use Voc for max voltage. 4S will over-volt @ 164.4V

Typically 3S max 60 cell panels on a 150V controller, so 2S2P is your maximum series option with 4 panels.

If shading/partial shading is a concern, 4P may be the winner for 12V or 24V battery.

Sunshine, so I have the panels installed and wired to the j box, I used the the 2S 2P design to start out. I have a 15A inline fuse on the positive side of each string and then into a 2into one adapter I added mc4 connectors inside the j box to connect the adapters to my 2/8 wire coming from the controller up to the roof. i wired to my disconnect and Turned on, and of course it is cloudy, so I’m only making 118 watts @68V/1.5A
i will have to use the system for a while and see if changing to a all parallel system is better. I will have to buy a combiner box if I decide to change. Thanks for the help, Sportz

 

[Sportzfann]

I checkled the voltage and polarity of the string before I connected the panels in parallel and this is the voltage of 1 series string 73.1V the VOC is 41.1 so I see some volt loss on the panels, I’m not sure how much is acceptable but this is what I’m reading before they are parallel together at the Jbox at this Time with cloudy skies. Thanks Sportz

 

[sunshine_eggo]

Voc is at CELL temperature of 25°C. Panels sitting in the sun get notably hotter than that. Your panel sticker shows a NOCT temperature of 45°C, which is basically the OPERATING temperature when it's 25°C with some typical assumptions.

Your datasheet:

https://www.jinkosolar.com/uploads/CheetahPerc%20JKM325-345M-60H-(V)-A3-EN.pdf

Lists NOCT Voc of 38V, so I would expect a 2S Voc of about 76V if the panels are hot from normal solar exposure. Remember that >80% of the energy hitting the panel is converted to heat. NOCT conditions also assume only 80% of normal solar intensity, so if it's more intense, more heat, lower Voc.