FM80 Settings help

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PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

FM80 Settings help

Post by PrepperBob » Mon Sep 09, 2019 3:32 pm

Sometimes I can be a little obtuse (slow to understand).
I am fully offgrid, there is no power coming up my mountain.
I have a 3200 watt solar array, Ten (10) 320 watt 24v pnels, wired as 5 sets of 48 volt, going to my combiner box.
From there, it goes to my FM80, and from there to my 48v battery bank consisting of eight (8) 6v 420ah batteries.

I am looking for the correct settings for my FM80, as I don't think I have it optimized.

On a side note, I removed my breaker box because I went with separate inverters for each area, instead of a whole house style....along with this is another issue as I don't have an inverter charger, so am looking for a 48v charger I can use with my genny for periods of low production. All I seem to find are golf cart chargers.

Thanks for any help you can give.

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Mon Sep 09, 2019 4:19 pm

The FM80 needs PV panel (input) voltage that is 1.5V higher than the battery voltage to charge. For a 48V battery, which can need to reach 57.6V nominal during the Absorb phase of the charge cycle, the input voltage would need to be at least 59.1V.

The optimum settings in the FM80 depend on battery type, and brand. I'd guess the battery here is made of Flooded Lead Acid monoblocks. The manufacturer may have charging specifications published for the battery, and they should be followed.

If specs are not available, the defaults in the FM80 are set for FLA batteries and should be fine, with the exception, perhaps, of Absorb time and Absorb end amps. These settings can be determined by experimenting if enough solar power harvest is available to run an extended Absorb cycle. Absorb should be run until the Amps flowing into the battery reach 2-3% of the total Amp Hour capacity of the battery - 8 to 12A in this case. If I had to guess, it would be an Absorb time of 3 hours.

Regarding AC powered chargers, 48V units are devilishly expensive. It almost pays to buy a small Outback inverter with built-in charger, or other inverter/charger combination. The Outback units have a good reputation for reliability, manageability, and robust operation. Also, lots of folks here know lots about them.

Another approach would be to get a quality multi-bank battery charger - say a 4 bank 12V charger at about 15A per bank. The charger leads could be attached to two adjacent 6V monoblocks (12V total between the two) and charge each of the four sets concurrently.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Mon Sep 09, 2019 6:39 pm

I see the Outback FXR3048A-01 inverter is around $1650... little high for me right now. I know, it's no excuse to not have a proper system.

The batteries are US L16HC XC2 - 6 Volt 420 Ah Solar Storage Battery %290.90 each, they are now $354 each at same place.
I couldn't find a datasheet on them
This is the link https://www.powerstridebattery.com/us-l ... ge-battery

I did this all in sections, each year buying a piece of the system..1 year the panels and mounting racks, the next the batteries, then the controller and combiner and wiring.

I'm old, broke, and tired...lol. Just trying to do the best i can. I'm sure my wiring and setup would give people nightmares if I posted pics, so I won't.

Thank you for your assistance, I tried to find a like button, but alas, I couldn't.

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Mon Sep 09, 2019 8:33 pm

I hear you brother!

You have a set of good old FLA deep cycle batteries of a type so universal, it is the Outback FM80 default profile. The one variable here is the capacity of the battery measured in Amp Hours (AH). Your battery is 420AH.

Good battery operation sets a maximum draw of 50% Depth of Discharge (DoD) before recharging fully. 210AH of charge can be drawn from the battery as a maximum in one charge cycle. That translates roughly as 48V×210AH=10kWH (kilowatt hours) of electric power. You may consider this battery able to deliver 10kWH of power before needing a full recharge.

That's provided they are new and in peak condition. If the battery is worn, it may easily lose 25% capacity (or more if very worn), so one might derate them to 7.5kWH. 7.5kWH is a respectable amount of power - both to consume and to produce.

What is consumed in a cycle should be replaced in the next charge cycle.

Heh! Class is over.

The PV panels have a set of specifications, usually in a data sheet, and on the label on the panel back. Do you have these specs?

Do you use a battery hydrometer? (One of those turkey baster looking things to measure battery charge - for those following along.)

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Tue Sep 10, 2019 5:59 am

raysun, I took these pics at approx 7:35 am this morning. The image for the panel info is skewed so I could get behind the mount :)
I also grabbed some shots of the various screens on the Outback, to see if anyone notices something funky that needs to be changed.
Don't yell at me for my inverter wiring..I need bigger grounding cables :), but it is what I had.

Pics are in this gallery: https://postimg.cc/gallery/1q7o7wvta/

and here are thumbnails:
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raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 7:07 am

OK good. The panels, wired 2 in series, have enough output voltage to charge the battery at its highest necessary voltage (during Absorb.)

The logging screen on the FM80 will show the last 120 days of charging activity. Starting with "today" the log can be read day-by-day by scrolling through the entries.

Look through the entries to get a sense of how effectively the battery is being charged. The first indicator is how long the Absorb phase executes each day, and how frequently the charging cycle reaches Float, indicated by the Float Time being greater than 0.

Check the FM80 settings for the Absorb Time. The default is 1 hour (60 minutes.) This battery type is better charged with an Absorb Time of 3 hours (180 minutes.) I would change the Absorb Time to 180 minutes. I would also change the Float Time to 180 minutes.

Note that a longer Absorb time will likely use more water in the battery. Be sure to check after making changes and running the longer Absorb cycle.

Also, the number of Amp Hours (AH) and Kilowatt Hours (kWH) delivered to the battery during the day are shown. These figures show the current that went into charging the battery combined with the current that went to the loads from the array while the sun was up and panels producing power.

What is not shown on the charger is how much current is drawn from the battery in total to service the loads, so the charge controller cannot show battery State of Charge (SoC). The most effective way to determine SoC on a Flooded Lead Acid (FLA) battery is to measure the electrolyte specific gravity with a hydrometer. Do you have one of these gadgets?
Attachments
Screenshot_20190910-035640_Chrome.jpg
Last edited by raysun on Tue Sep 10, 2019 8:13 am, edited 5 times in total.

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 7:25 am

20190910_041523.jpg
This screen shows the charge controller has been set to deliver a maximum current of 42A. I believe this was set to make sure the charger was delivering a nice safe charging current of 10% of the total battery capacity.

IMO this is being too safe. The accepted charging rate for this type of battery is 10 - 30% of capacity. At the low end of the charge rate (10%), the power collected from the array is limited to roughly 48V x 42A = 2016W. At maximum charge 57.6V x 42A = 2420W.

When the charge controller is supplying both charging and load current (as it does during the day) the 42A setting leaves a lot of power on the table, so to speak, when the array is operating at full output.

You can scroll through the charger log entries looking at the kWP (kilowatts peak) to see the maximum instantaneous power the system delivered each day.

I would reset the maximum current to the charger's default 80A. (80A output will never be reached by a 3200W array, but there's no sense in throttling the controller back to less than the maximum the array can deliver.)

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 7:59 am

Screenshot_20190910-044915_Chrome.jpg
I can't quite make out the details here. Is this 3 inverters drawing power from the battery and servicing 3 separate load circuits?

Do you have an idea of maximum load and current draw?

A battery monitor of some type is necessary, IME. There are cheap Chinese monitors available that are better than no monitor. Here is a typical example of a "current counter" style (characterized by the current shunt that is included.) These are much better than the voltage meter type "fuel gauge" monitors. (I don't necessarily endorse any particular product, this is simply the first one that popped up when I searched. There are many of these types of monitors. Check them out before plunking down 20 bucks.)

https://www.amazon.com/gp/aw/d/B07FN3VX ... UTF8&psc=1

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 8:24 am

Screenshot_20190910-051740_Adobe Acrobat.jpg
The FlexMax 80 manual shows the Absorb Time and Absorb End Amps settings in the Advanced menu.

The default Absorb Time is 60 minutes. I'd set to 180 minutes for FLA battery of the capacity you have.

The Absorb End Amps is the measure of the minimum current that would flow into the battery when fully charged. It is usually 2-3% of total battery capacity. I would set this to 12 Amps for a 420AH FLA battery. If Absorb End Amps is reached, the charger stops the Absorb cycle and immediately switches to Float. If Absorb End Amps is set to 0, then this will be ignored, and the charge controller will always try to run Absorb cycle for the Absorb Time setting.
Last edited by raysun on Tue Sep 10, 2019 2:55 pm, edited 2 times in total.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Tue Sep 10, 2019 8:56 am

raysun wrote:
Tue Sep 10, 2019 7:59 am
Screenshot_20190910-044915_Chrome.jpg

I can't quite make out the details here. Is this 3 inverters drawing power from the battery and servicing 3 separate load circuits?

Do you have an idea of maximum load and current draw?

A battery monitor of some type is necessary, IME. There are cheap Chinese monitors available that are better than no monitor. Here is a typical example of a "current counter" style (characterized by the current shunt that is included.) These are much better than the voltage meter type "fuel gauge" monitors. (I don't necessarily endorse any particular product, this is simply the first one that popped up when I searched. There are many of these types of monitors. Check them out before plunking down 20 bucks.)

https://www.amazon.com/gp/aw/d/B07FN3VX ... UTF8&psc=1
Yes, that is 3 separate inverters. The 800 watt is powering the living room, 1 of the 1500 watts is powering my sons room, the other 1500 is powering my room and the bathroom. Not mounted yet is the 2500 watt inverter for the kitchen

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 9:05 am

OK. With that much potential inverter capacity, the system really needs a battery monitor. All of those inverters cranking to anything near capacity will draw a battery down in fairly short order.

Not that all of them will sustain peak output simultaneously for any length of time, but the "worst case scenario" of 800+1500+1500+2500=6300W. 6300W/48V=131A draw from the battery. About 1 hour of maximum draw would bring the battery down to a low SoC.

In reality, the typical total power usage is much less, but needs to be sustained over a much longer period. Assuming the battery is contributing some, or all, of the load current for 20 hours per day (with the charge controller contributing all load current for 4 hours), the total "safe" battery current draw is 10A per hour, or an average power output of 450W.

Do you have a KillAWatt meter? A very useful tool to test and log power flow in a circuit. https://www.amazon.com/gp/aw/d/B000RGF2 ... eva_mobile
Last edited by raysun on Tue Sep 10, 2019 10:14 am, edited 3 times in total.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Tue Sep 10, 2019 9:10 am

heading back to make suggested changes, try to find my hydrometer, and check water levels.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Tue Sep 10, 2019 9:12 am

raysun wrote:
Tue Sep 10, 2019 9:05 am
OK. With that much potential inverter capacity, the system really needs a battery monitor. All of those inverters cranking to anything near capacity will draw a battery down in fairly short order.
None of those inverters have ever had near capacity, nor even half capacity. I over did it for future use :)
I will look at battery monitors and get one in short order.

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 9:26 am

You asked about external chargers. I use one of these with good results: https://www.amazon.com/NOCO-Genius-GEN4 ... 2005&psc=1

The 4 banks each can deliver 10A for 40A total. On your battery, each bank would be wired across 2 of the 6V monoblocks. The 4 banks would service the entire battery.

$300.00 is not cheap, but this unit is pretty bullet-proof, is tolerant of most generator AC output, and does a good job maintaining the battery during times of low sun.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Tue Sep 10, 2019 10:51 am

Suggested changes made, except for max float time..couldn't find any setting for that.
Have to pick up a new hydrometer tomorrow when I go to work, not one of those cheapo ones.

I found a 4 bank 15 amp charger, 48v 60A, for $379. For what it does, that's reasonable

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 12:00 pm

PrepperBob wrote:
Tue Sep 10, 2019 10:51 am
Suggested changes made, except for max float time..couldn't find any setting for that.
Have to pick up a new hydrometer tomorrow when I go to work, not one of those cheapo ones.

I found a 4 bank 15 amp charger, 48v 60A, for $379. For what it does, that's reasonable
There's no float setting to find. Other parts in the Outback system control that. My bad

Whatever kind of hydrometer, I now always buy two. I know I'll drop and break one almost right away.

A good AC charger is a direct contributor to battery health.

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Tue Sep 10, 2019 12:47 pm

Do you have the Remote Temperature Sensor (RTS) cable that connects to the FM80? The sensor end attaches to a battery case. This allows the system to use Temperature Compensation during charging, which is an important function for battery longevity.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Tue Sep 10, 2019 4:38 pm

No, but I will now :)

pss
Forum Guru
Posts: 273
Joined: Mon Jul 24, 2017 8:40 am
My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

Re: FM80 Settings help

Post by pss » Tue Sep 10, 2019 8:04 pm

Hey Prepper Bob. You have been getting excellent information from the forum members. I wish I had that when I started.

Now, for your solar array. Your panels are not 24V as listed in your equipment.
You have 10 panels, connected 2 in series and 5 in parallel.

The photo of the panels shows the VOC to be 45.9. In series, this adds to 91.8 volts at 77 degrees F. Your Flexmax can handle an input up to VOC = 150. You cannot go to three panels in series safely.
Next, your power per panel is 8.56 amps rated at up to 37.4 volts. This means that each set of 2 panels under ideal conditions would output 8.56 Amps at say 74.8 volts. Multiply this x 5 for the parallel strings and you have a rated system of 3201 watts with 42.8 amps of current under bright sunshine at noon at 77 degrees on a clear day. In essence, a Flexmax 60 would be just fine. Now, you also have capacity to add 6 more panels to your array. That would be 320 watts x 2 in series and three in parallel. This would amount to a face value of 68.48 amps. YOu just need to make certain the wire from the combiner box into Flexmax is of sufficient gauge to handle both the amperage (flow of current) and distance (voltage drop over length of wire, ie. resistance to current flow).

Now, you should let people know what are the coldest daytime highs at your location and warmest summer daytimes temps at your location. This will help determine the power output you could reasonably expect.

Now, to fully charge your batteries, the Flexmax will require an input voltage of about 18-24 volts above your charged voltage to be efficient. So, to hit 57.6 volts and fully charged for your battery bank, you will want your Flexmax to have an input of about 77 volts or more. The program software of the Flexmax will adjust to maximize amperage flow into the batteries per the info you have received already as well as battery manufacturer's recommended charging parameters.

Also, it would be nice to see a photo of your battery bank and know the gauges of the wiring you have used as well. Also, are your batteries fused at the positive terminal and also possess an on/off switch prior to reaching the inverter?

Safety first.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Wed Sep 11, 2019 6:16 am

My panels were marketed as, and sold as, 24v panels, so I refer to them as 24v panels :) I know the voltage varies.

The lines from the combiner box (approxn 60ft) are 6ga UltraFlex welding cable and run to this before the FlexMax:
Image
the cables from the FlexMax (12ft) are 2ga UltraFlex welding cable, and run to this before the batteries:
Image

I have another pair of panels, 24v 300 watt, that I will add in as I have a 6 string combiner box, and only 5 strings so far.

On average we have 209 sunny days, just over the national average of 205
Average July temp is 89, the highest this year was 98
Average January temp is 25, lowest this year was 20

Batteries are not fused, and they use 2ga cables, again I use the UltraFlex welding cable

Plans for next 2 years are to add another solar array, FlexMax, and a battery bank to double the amp hours.
Just have to decide which makes more sense to get first.

Oh, as a side note, all my lighting is 12v RV mushroom lights. They, as well as some 12v outlets in each room, run from a BlueSea fuse box. The 12 v is supplied from a 48v to 12v stepdown that is used for golf cart accessories.

pss
Forum Guru
Posts: 273
Joined: Mon Jul 24, 2017 8:40 am
My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

Re: FM80 Settings help

Post by pss » Wed Sep 11, 2019 8:32 am

Bubble burst: Forget the 24V nonsense. Either the seller didn't understand or you didn't understand or the seller told you what you wanted to hear.

The Xscorpion circuit breakers are for 12 volt automobiles, not for the voltages of your application and so should be removed.

The inline switch shows a car battery icon. The switch must be rated to handle the voltage and amperage of your devices.

Each string of batteries should have a fuse installed at the positive terminal. A good choice is Blue Sea Marine terminal fuse block of appropriate amperage. This protects your batteries and your inverter. Then an inline ON/OFF switch of proper amperage and voltage again such as from Blue Sea Marine.

Welding wire cable uses lots of small stranded wire and is therefore harder to get an excellent connection when crimping. When using welding wire, the idea of crimping to the terminal is to essentially "cold weld" the wires to the terminal. For this purpose, a hydraulic crimp tool works best, say in the 12-16 ton range of compression. They are readily available and will make certain the terminal lug has a good lasting connection. Then heat shrink tubing should be applied over the neck of the wire to near the flat portion of the terminal lug to reduce the risk of shorting out the connection.

From your battery manufacturer:

Bulk Charge Constant current @~10% of C/20 Ah in amps to 2.45+/-0.05 volts per cell

(e.g. 7.35 volts +/-0.15 volts per 6 volt battery)

2. Absorption Charge Constant voltage (2.45+/-0.05 vpc) to 3% of C/20 Ah in amps then hold for 2-3 hours and terminate charge

Charge termination can be by maximum time (2-4 hr) or dV/dt (4 mv/cell per hour)
• (Optional Float Charge) Constant voltage 2.17 vpc (6.51 volts per 6 volt battery) for unlimited time
• Equalization Charge Constant voltage (2.55+/-0.05 vpc) extended for 1-3 hours after normal charge cycle (repeat every 30 days)

Notes: Charge time from full discharge is 9-12 hours.
Absorption charge time is determined by the battery but will usually be ~3 hours at 2.45 volts per cell.
Float time is unlimited at 2.17 volts per cell.
Specific gravity at full charge is 1.270 minimum

Your system will be stressed when ambient temperatures hit the mid 90's and above. This goes for reduced solar PV output, higher inverter temps and battery temps all mean adjustments have to be made, especially to the battery charging parameters. Same goes for cold weather on the batteries. Are the inverter and battery bank in a climate controlled environment?

Battery maintenance is very important. Besides the correct charging parameters, you need to visually check the water levels in the batteries every 30 days. Make sure the plates never get exposed to air and only fill with distilled water, never anything else. Depending on your system demands you may need to top off monthly or go even as long as 6 months without adding distilled water, but you've got to be diligent and check the water levels.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Wed Sep 11, 2019 9:50 am

I understand what you are saying, I'm just saying the manufacturer themselves (Mission Solar), and Solarblvd referred to them as "Mission Solar 320 watt 24 volt Mono-Crystalline Solar Panels", which is what they are listed as on my invoice from them. Maybe they lied...but they work :), or as you say, they sold me what I wanted to hear.

That aside, yes, that first xscorpion is not correct. It was recommended to me on solar-power forum, but after emailing xscorpion, they said it is only rated to 36v dc.
I will be replacing it. Do you have any suggestions?

The other inline switch just shows a generic battery, not necessarily a car battery. It is an Ampper 48 V Battery Master Switch made for Marine use with 3/8 studs, although some sites list it for car, rv, and marine among others, and show it as 12-48 volts.

Batteries are outside in a battery box, everything else is in a temp controlled environment. The battery box has a 4 inch intake from the house (power room), and a 4 inch vent, on opposite sides, so it is slightly regulated.

Batteries are checked every Sunday afternoon as to water level, and I only use distilled water, and that very rarely. I always have on all batteries.

Yep, my crimps aren't the recommended style, and will be redone and shrink tubed like the rest of my system is, as I can.
This is the crimper I'm picking up from my son again:

Image

This is how my battery bank is configured, except imagine it folded in the middle :)

Image

Can you explain the purpose of having a fuse on the positive terminal, if I have a 100a fuse inline between the batteries and the controller? Isn't that the same thing? Should it be a different amp rating?

Thank you for the bat info.

pss
Forum Guru
Posts: 273
Joined: Mon Jul 24, 2017 8:40 am
My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

Re: FM80 Settings help

Post by pss » Wed Sep 11, 2019 10:22 am

Good info, thanks.

As for the fuse on the battery terminals, current flows in and out of the batteries. In from the charge controllers and out to the inverter. Maybe even in from a generator or grid connected charger. All of this is subject to bad connections, shorting, power surges and even lightening anywhere along the array to charge controller, even back to inverter. And, even the batteries themselves can short out and fail. So since your batteries are expensive, the use of a terminal block fuse assures you that current into and out of the batteries will be protective. And, when you are working on the system, an inline switch from the battery bank to the inverter/charge controller will allow you to safely turn off the bank for maintenance of wiring.

I also suggest you coat the terminals of the battery bank with a product called Kopr Kote. This will protect from corrosion of the connections and should also be used at splices, etc.

In my own case, I have 4 strings of batteries (yes, I know three is optimal), each with a terminal block fuse. I watered up the batteries and when checking the voltages with a meter about a month later as well as the water levels, I noticed in one string the levels were fine, but the other three strings the levels were down. Also, the voltages did not match up. Upon inspection, i found the culprit to be a blown terminal fuse block. I performed a careful inspection of all wiring and concluded it must have been a poor connection and power surge. I replaced the terminal fuse block and all is well. So that visual window on the block helps a lot and my batteries were safe.

Between the batteries and the charge controller you should have a circuit breaker installed rated at the maximum amp of the CC , in your case an 80 amp breaker. This safeguards the CC and allows it to be disconnected from the battery bank if spikes occur.

And for the connections from the combiner box to the charge controller, in between you need to have installed a DC disconnect switch, preferably with a fuse large enough to handle the amperage and voltage of your array. You can easily find these switches with the models that hold the fuses. Then purchase the correct fuse to fit the box. This way your CC is protected from surges and lightening at your PV as well as other arcing/shorting conditions.

Your PV combiner box should also have a DC lightening arrestor installed at the box and your load panel should have an AC lightening arrestor installed.

Your PV array should be grounded at the array with a 10 foot grounding rod installed. That wiring goes to the ground of the combiner box. Your inverter and charge controller should be grounded with 2 grounding rods installed no more than 10 feet apart, connected together by a continuous ground wire and then connected to your load panel, inverter and charge controller and battery box.

You have a lot of time and money in your system. If it is built our right to code it will be safe and require a minimal amount of maintenance.

I know this sounds like a lot, but with all the people who look to this forum for advice, it is best to tell the whole, complete, safe story. Nobody wants a fire or an electrocution on their hands.

raysun
Forum Czar
Posts: 755
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: FM80 Settings help

Post by raysun » Wed Sep 11, 2019 11:00 am

A common conception is fuses and circuit breakers are put in place to protect equipment, this is only indirectly true, their primary purpose is to protect wiring. Each breaker (disconnect is an alternate term) should be sized to keep current below the "ampacity" of the wiring its protecting.

The DC disconnect between Charge Controller and Battery is typically 80A, as this is the limit of the controller's normal output, and wiring is usually rated at or above that capacity. The 2GA is obviously more than enough. This is a typical 80A disconnect that mounts on DIN rail: https://www.amazon.com/MIDNITE-150VDC-C ... B06Y1KNDCR

The DC disconnect between battery and equipment for a 48V system is commonly 125A-250A@150V. A 175A unit will handle battery current sufficient to drive an 8kW system. Your battery cables are rated at 400A (IIRC, and only now working on my first cup of coffee), so a 175A DC breaker is going to be enough.

For safety, reliability, and serviceability, all the DC disconnects can be mounted in a panel. As long as we are spending your money, I'd suggest this: https://thesolarstore.com/mini-dc-disco ... -1104.html

With your DC fuse (if properly rated) at the battery box, and the 175A disconnect at the equipment room, the battery circuit would be well-protected.

LOL! I bet you originally posted looking for some simple guidance. Ask an engineer what time it is, and they will tell you how to build a clock.

When you get over the indigestion of digesting this 27 course meal on battery systems, be sure to ask us about the other Balance of System components like surge suppressors, ground fault and arc fault disconnects for the panel array, and whatever else we can dredge up. ROFL!

Upgrading the existing PV array to 12 panels of the current rating is no problem for the FM80. Adding a 2nd array and a 2nd FM80 was one of the best things I've done in a while. It will require duplicating the wiring and breakers all the way to the connection at the battery disconnect.

PrepperBob
Forum Member
Posts: 11
Joined: Mon Sep 09, 2019 3:12 pm
My RE system: 10 24v 320 watt Mission Solar panels in 5 sets of 48v
Outback FlexMax 80 Controller
8 6v 420ah batteries in 48volt config
6 string Combiner, only 5 used.
6ga from combiner to controller
2ga from controller to batteries
(2) 1500w Reliable inverters
(1) 800w Reliable inverter
12v lighting, all 10 ga wire
Location: Arkansas Ozarks

Re: FM80 Settings help

Post by PrepperBob » Thu Sep 12, 2019 3:26 pm

Ordered some parts, will update when they arrive.
Everything running smooth so far, thanks again.

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