Best panel config and settings for Outback 80 with LiFePO4

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Best panel config and settings for Outback 80 with LiFePO4

Postby McG on Tue Nov 14, 2017 2:13 am

Good day everyone.
I have had my Outback since 2008 and it's still going strong. \:D/ I am currently upgrading the solar array. What I need to find out is what will be a good (best) configuration to connect 12 x 100w solar panels to the Outback and what is best settings for charging LiFePO4?

I am currently contemplating connecting 6 panels in Series x 2 arrays and parallel them to the Outback. Any inputs will be appreciated.
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McG
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Posts: 8
Joined: Mon Sep 27, 2010 2:36 am
My RE system: FlexMax80, 468Watt Uni-Solar array in parallel as charging input to 6x220AH/6volt deepcycle SLA batteries connected to output 12V 660AH to power my motorhome.

Re: Best panel config and settings for Outback 80 with LiFeP

Postby Mike Curran on Tue Nov 14, 2017 8:06 am

Check out these docs I got from SimpliPhi:



Last edited by Mike Curran on Thu Nov 16, 2017 6:52 am, edited 1 time in total.
Mike Curran
OutBack Guru
 
Posts: 331
Joined: Sat Aug 28, 2004 6:28 pm
Location: Chagrin Falls, Ohio
My RE system: Outback: 8 (2x4) Evergreen 180's into one MX60, 6 (2×3) ALEO S79-300's into one FM80, 2 grid-tied GVFX3524's classic stacked for 120/240VAC, 12 Surrette/Rolls 2V x 1766Ah, Hub10.3, Mate3, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar: 30 (2x15) 235W panels with Enphase M215 microinverters. 6,450 nameplate watts AC, grid-tied.

Re: Best panel config and settings for Outback 80 with LiFeP

Postby McG on Thu Nov 16, 2017 12:19 am

Thanks Mike.
I am still waiting for comments regarding the panel configuration though: 2 sets of 6 panels in series or 12 panels in parallel? I guess 12 in parallel will push the Short Circuit Amps too high for the Outback FM80? :-k
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McG
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Posts: 8
Joined: Mon Sep 27, 2010 2:36 am
My RE system: FlexMax80, 468Watt Uni-Solar array in parallel as charging input to 6x220AH/6volt deepcycle SLA batteries connected to output 12V 660AH to power my motorhome.

Re: Best panel config and settings for Outback 80 with LiFeP

Postby Mike Curran on Thu Nov 16, 2017 7:19 am

Hey McG - A lot depends on your system. You need the input voltage to your FM80 to be higher than your battery voltage, and by more than a couple volts. So if you're running a 12V battery that'll need equalization at 15.5V, your panel setup (series, parallel, whatever) should be rated to supply 24 volts, minimum. And so forth for a 24V battery, etc.

Also, the FM80 will fry if you supply it more than 150V from your PV so that limits the number of panels you can put in series.

Finally, with an FM80 output rating of 80A, a 12V battery system could accept a maximum of 80 × 12 = 960Watts of solar, a 24V battery system could take a max of 80 × 24 = 1920W, and a 48V battery, 80 × 48 = 3840W.

So if you want to use all your 1200 watts of your PV panels, you need a 24 volt battery, and your array output needs to be at least 48V (imo). 6 panels in series might exceed the FM80's 150V input limit, depends on your panels. At 100W apiece it might work, but again depends on panels. - Mike
Mike Curran
OutBack Guru
 
Posts: 331
Joined: Sat Aug 28, 2004 6:28 pm
Location: Chagrin Falls, Ohio
My RE system: Outback: 8 (2x4) Evergreen 180's into one MX60, 6 (2×3) ALEO S79-300's into one FM80, 2 grid-tied GVFX3524's classic stacked for 120/240VAC, 12 Surrette/Rolls 2V x 1766Ah, Hub10.3, Mate3, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar: 30 (2x15) 235W panels with Enphase M215 microinverters. 6,450 nameplate watts AC, grid-tied.

Re: Best panel config and settings for Outback 80 with LiFeP

Postby McG on Thu Nov 16, 2017 10:42 pm

Thanks a lot for all the info Mike. Can you tell me why the input is limited to 80 x 12 = 960W?

My panel specs: 100W
Voc = 21.7
Isc = 6.1
Vmp = 17.7
Imp = 5.7

So I worked out that 6.1A x 2 = 12.2A which is sway within limits for FM80.
21.7V x 6 = 130V which is still 20V below FM80 limit.
That is why I thought to go 6 panels in series x 2 arrays.

Oh, and remember I have an 800Ah 12V lifepo4 battery which can apparently take as much as you can throw at it. :?:
User avatar
McG
Member
 
Posts: 8
Joined: Mon Sep 27, 2010 2:36 am
My RE system: FlexMax80, 468Watt Uni-Solar array in parallel as charging input to 6x220AH/6volt deepcycle SLA batteries connected to output 12V 660AH to power my motorhome.

Re: Best panel config and settings for Outback 80 with LiFeP

Postby Mike Curran on Fri Nov 17, 2017 11:06 am

McG wrote:Can you tell me why the input is limited to 80 x 12 = 960W?


Power into the FM80 = power out, so with an 80A output limit into a 12V battery, input is limited to output = 960W. You can't put more power in than what the output limit is, or you'll exceed the output limit. I've attached 2 photos of an article from Home Power magazine that I used when I built my first system with an MX60 charge controller (rated for 60A output). Hope this helps. Break out your magnifying glass :grin: (sorry!)

15109414960131438733879.jpg

1510941598746-2010371026.jpg


Note Outback also has a string sizing tool on their website that can help you decide what array configuration is best. http://outbackpower.com/outback-support ... izing-tool

McG wrote:Oh, and remember I have an 800Ah 12V lifepo4 battery which can apparently take as much as you can throw at it. :?:
You'll only be able to throw 80A at it from your FM80 so unless you add more PV and another charge controller, your battery's capacity to accept a charge isn't really a factor. - Mike
Mike Curran
OutBack Guru
 
Posts: 331
Joined: Sat Aug 28, 2004 6:28 pm
Location: Chagrin Falls, Ohio
My RE system: Outback: 8 (2x4) Evergreen 180's into one MX60, 6 (2×3) ALEO S79-300's into one FM80, 2 grid-tied GVFX3524's classic stacked for 120/240VAC, 12 Surrette/Rolls 2V x 1766Ah, Hub10.3, Mate3, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar: 30 (2x15) 235W panels with Enphase M215 microinverters. 6,450 nameplate watts AC, grid-tied.


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