Now I remember why auto charge termination disabled

Discussion about OutBack Inverters in Grid Tie Applications

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Mike Curran
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Posts: 2825
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Now I remember why auto charge termination disabled

Post by Mike Curran »

This morning with partial sun my older system with 2 FM80s met charge parameters. In the past, this would enable selling and artificially raise the float voltage setpoint to the absorb setting, thereby forcing voltage to rise to the sell setpoint. At the same time, the FM80 status indication goes to "bulk".

This past week I enabled charge termination to make my inverters stop charging once charge return amps is met - see this thread for background: viewtopic.php?f=15&t=15856

However, today, subsequent to enabling charge termination, I found both FM80s in float mode (see screenshot)
Screenshot_20201223-120821.jpg
following CPM, and no selling to grid. It's a distant memory now, but I believe many moons ago I discovered that I had to disable auto charge termination in order to insure my CCs went to bulk following CPM.

Seems like there's a flaw in this - why can't I have charge termination AND get to selling after CPM??? :?:
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

Mike Curran wrote: Wed Dec 23, 2020 9:21 am This morning with partial sun my older system with 2 FM80s met charge parameters. In the past, this would enable selling and artificially raise the float voltage setpoint to the absorb setting, thereby forcing voltage to rise to the sell setpoint. At the same time, the FM80 status indication goes to "bulk".

This past week I enabled charge termination to make my inverters stop charging once charge return amps is met - see this thread for background: viewtopic.php?f=15&t=15856

However, today, subsequent to enabling charge termination, I found both FM80s in float mode (see screenshot) Screenshot_20201223-120821.jpgfollowing CPM, and no selling to grid. It's a distant memory now, but I believe many moons ago I discovered that I had to disable auto charge termination in order to insure my CCs went to bulk following CPM.

Seems like there's a flaw in this - why can't I have charge termination AND get to selling after CPM??? :?:
Not being a grid guy, I have little to add, but it seems the key would be selling at or near Float voltage. Is that possible?
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Mike Curran
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Posts: 2825
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Now I remember why auto charge termination disabled

Post by Mike Curran »

Yeah - previously* I had to lower the sell setpoint below the float setpoint, and that worked, but since my battery temperature varies from summer to winter and float is temperature compensated while sell is not, I had to remember to change theses settings when the battery temperature changed. Kind of a pain...

*Before I had an FNDC and its CPM functionality

Edit: Working now
Screenshot_20201223-125304.jpg
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

It was 59°F at sunrise, and Kilauea is erupting into Halemaumau crater.

Winter sucks. 🤣
User avatar
Mike Curran
Forum Emperor
Posts: 2825
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Now I remember why auto charge termination disabled

Post by Mike Curran »

No volcanoes here so I guess that's a plus.
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
fcwlp
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My RE system: GS8048A, FM80 w/3,600W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed.

I install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Now I remember why auto charge termination disabled

Post by fcwlp »

Mike, do you have grid-tie mode enabled on the FM80s?
User avatar
Mike Curran
Forum Emperor
Posts: 2825
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Now I remember why auto charge termination disabled

Post by Mike Curran »

fcwlp wrote: Wed Dec 23, 2020 11:35 am Mike, do you have grid-tie mode enabled on the FM80s?
Yeah, both FMs are like this:
Screenshot_20201223-153214_Samsung Internet.jpg
It was selling earlier today so definitely grid tied. My issue is mainly that when auto charge termination is enabled, the Mate feature that raises the float voltage setting to the absorb setpoint (to make selling more likely) is defeated.
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
fcwlp
Forum Emperor
Posts: 1018
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed.

I install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Now I remember why auto charge termination disabled

Post by fcwlp »

That is how my FM80s are setup. One difference is that my "Wakeup VOC Change" default is 6V. What level of firmware are your FM80s? Does anyone have a list of FM60/80 firmware changes?
User avatar
Mike Curran
Forum Emperor
Posts: 2825
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Now I remember why auto charge termination disabled

Post by Mike Curran »

fcwlp wrote: Thu Dec 24, 2020 8:14 am That is how my FM80s are setup. One difference is that my "Wakeup VOC Change" default is 6V. What level of firmware are your FM80s? Does anyone have a list of FM60/80 firmware changes?
Both of them are fw 003.003.000. One I bought new in February 2020. The other was repaired by OB in March, 2020, and received a firmware update while in their shop, so 3.3 is the latest as of March.
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
gtarolli
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- 6 SimpliPhi 3.4 kWh LI batteries (400ah , 20kWh)
- 1 Honda EM5000 generator + one EU3000
Location: Wainiha, Kauai, HI

Re: Now I remember why auto charge termination disabled

Post by gtarolli »

The other day I noticed that my SOC jumped to 100% when my Net Amps reached 0(zero) on the Meters page (of the web interface). This is not the corrected amps, i.e. it assumes the battery charge factor is 100%. My correct net amps on the Status page still read about 20 amps below 100%. I have charge terminate disabled, else I believe I would have entered Float mode - as this event is the special Float mode protection mentioned in the FNDC app note I posted on another thread. So I remained in Bulk and eventually reached Absorb.

So if you have charge termination enabled, this might cause the system to go into FLOAT mode and probably stop charging very early, depending on the separation between the two Net Amp readings. I have BCF set to 94% so the diff is larger than if you have it set to 98%.

I trust the voltage enough to stop charging, and not overcharge. Once LIFP are full, they quickly reach the absorb voltage and then the system will just hold the voltage for a while and then drop to float. I haven't seen any issue with this (yet).
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

The Net Battery and Corrected Net Battery AH readings are definitely different creatures. Seeing a 20AH difference is not unusual on my system at the point Net Battery goes to zero. The system resets SoC to 100% and "zeros out" both Battery AH values.

From that point, I track (when interested) the additional AH needed to reach charge termination. Its typically 5AH.

I consider the difference between the prior-to "zeroed out" Corrected Net Battery value, and the AH needed to reach full charge to be error induced by the FNDC not computing CNB correctly. This may be due to Battery AH Capacity, Charge Efficiency, and/or Peukert's Constant not specified correctly.
User avatar
Mike Curran
Forum Emperor
Posts: 2825
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Now I remember why auto charge termination disabled

Post by Mike Curran »

Man, I'm glad I'm grid-tied. You off grid guys are way over my head! :grin:
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

Mike Curran wrote: Thu Dec 24, 2020 12:16 pm Man, I'm glad I'm grid-tied. You off grid guys are way over my head! :grin:
🤣🤣

I was thinking just the same thing about being grid-tied!
TheWaterman
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Re: Now I remember why auto charge termination disabled

Post by TheWaterman »

I bought two Big Battery 3.8kwh 79 Ah 2yrs ago and wonder if i shoul de enable this function?
Attachments
Screenshot_20220615-144844 (1).pdf
Power bank
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raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

TheWaterman wrote: Sat Jul 23, 2022 5:22 pm I bought two Big Battery 3.8kwh 79 Ah 2yrs ago and wonder if i shoul de enable this function?
What is the charging profile for the battery?
TheWaterman
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Re: Now I remember why auto charge termination disabled

Post by TheWaterman »

Attached is the specs for battery banks.
Attachments
voltage specs.pdf
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raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

What charged voltage target is being used?
Assuming a single-stage charge profile, essentially Bulk charge to the specified charged voltage, the easiest way to program Outback chargers (inverter charger, Flexmax charge controllers) is to set:
Absorb Voltage = selected charged voltage
Absorb Time = 0.1H
The settings will hold the charged voltage for 0.1 hours (6 minutes), then terminate, and proceed to the Float phase.
Since the battery sheet doesn't specify a target end amps, there's nothing to set Charged Return Amps, so Auto Charge Termination Control won't execute. Nor is it needed in the above charging profile. Disable it.
TheWaterman
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Re: Now I remember why auto charge termination disabled

Post by TheWaterman »

Thanks for the reply. The hvco(bulk) is set to 58.4volts and the lvco is set to 43.6 volts. The web interface and Opticsre is off .6 volts higher than what the voltage gauge on the battery banks show. I checked this with my volm meter and the gauge is on.
Float is set to zero time and equalization is set to zero also. See attached.
Attachments
Screenshot_20220723-205024.png
Screenshot_20220723-205005.png
Screenshot_20220723-205017.png
TheWaterman
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Re: Now I remember why auto charge termination disabled

Post by TheWaterman »

Follow up.
Attachments
Screenshot_20220723-205108.png
Screenshot_20220723-205100.png
Screenshot_20220723-205047.png
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Now I remember why auto charge termination disabled

Post by raysun »

I won't pretend I understand Big Battery's specifications. There is a parameter called Cell Over Charge = 4.20V. The battery is 12 cells in series. I would have guessed the maximum charge voltage of 12 x 4.20 = 50.4V, but that is well below their Voltage Range (max) = 58.8V.
I assume you've managed to work out a proper charging voltage.
The hvco(bulk) is set to 58.4volts
What is meant by this setting? Is High Battery Cut-Off being used to disable the inverter charger when 58.4V is reached? The inverter is an FX3048T? That model doesn't have HBCO built in, so is this using the FNDC AUX relay somehow?
Other screen captures appear to show programming for the FNDC AUX relay. What is it being used for?
I assume Port 2 is a FlexMax charge controller. It looks to be set to bulk charge to 58.0V then terminate. The Absorb Time of 0H will terminate Absorb phase immediately. However, Float Voltage is also set to 58.0V, so the FlexMax will attempt to hold that voltage until sunset. (Float cannot be defeated on the FlexMax.)
The Port 1 (inverter charger) settings, have different operating rules from those of the FlexMax. Absorb Time = 0 on the inverter skips the Bulk and Absorb phases entirely and proceeds directly to Float. Float Time = 0 skips the Float phase. I'd imagine the inverter is not providing any charging service. To enable Bulk, set Absorb Time = 0.1H on the inverter.
It appears values have been entered for the FNDC Battery Charged parameters. What is called "Full Voltage" in the web app is called "Charged Voltage" in the Mate UI. The docs recommend it be set 0.4V lower than the lowest Absorb Voltage setting. (Charged) Return Amps = 8A was derived from some other information provided by the vendor?
Its important that the battery voltage measured by the inverter and charge controller voltmeters (FNDC as well) match the battery voltage measured at their respective battery terminals as closely as possible. Both the inverter and FlexMax have software calibration that will get "in the ballpark". The FM and FNDC both have hardware calibration methods as well.
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