Configuring generator to fully charge batteries

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rpbancroft
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Configuring generator to fully charge batteries

Post by rpbancroft » Mon Jan 14, 2019 11:22 am

Hey there! I'm having trouble configuring our generator to reliably fully charge the batteries. We have what I would guess is an "out of the box" configuration, for the most part, regarding the generator (or so I've been told by our installer). I only have theories about what the inverter or charge controller is using to determine when to stop charging the batteries, but what I do know is whatever they're using isn't working very well for us. I hope someone can shed some light on what's going on, and provide some tips on how to change it.

So here's what happens. FYI, all of these % SoCs are reported by the MATE3S (and seem, based on our usage patterns, to be accurate to the actual capacity in the batteries). Let's say we get a fully sunny day that charges the batteries to 100%. That night, we use a heap of power and take the batteries down to 70%. If I run the generator right after that, generally I've observed that the charge will go up to 95% or higher. I'm not really sure what the time frames here are (in other words, I don't know how long I have to wait before the SoC it charges up to changes); this is just a general gauge.

However, let's say I don't charge it that night, but instead leave it until the next day. It looks like it's gonna be sunny, so I don't use the generator until that evening. However, it turns out not being sunny at all, and the batteries hang around ~70% all day. By the time I'm home, they're around 63%. I turn on the generator, and, after a short while (probably around an hour), the generator stops charging them at 78%. Nothing I know how to do will make it charge them higher.

I've tried starting the generator after the batteries discharge just a few % (down to, say, 74%), but the best I've been able to do is get it to 84%. Usually it only will go to like 79% or so. I've also tinkered with the input amperage from the generator, but this doesn't affect how much they charge the batteries; it only affects how much current the system will draw from the generator.

This is especially problematic if we have like 5 cloudy days in a row. Now I'm sitting with a really narrow usage window, where 78 - 81% is my highest possible charge (until the sun comes back; I've even had my highest be 73%, and that's super sucky), meaning I have to turn on the generator quite frequently, and have to stay up really late on super cold nights to make sure we don't run out of batteries overnight (due to heat tape usage). We don't have anything like AGS set up yet.

It's probably obvious by this point, but I'd like for the generator to consistently charge the batteries to around 95%, no matter what has happened in previous days. 100% would be wonderful, if that were possible. Does anyone know any way to do that? What other information would you need to determine what's going on? I'm still really new to using Outback stuff, and managing off-grid systems in general, so I'm kind of at a loss here.

Thanks so much!

~Ryan

blackswan555
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Re: Configuring generator to fully charge batteries

Post by blackswan555 » Mon Jan 14, 2019 12:18 pm

Have you changed any of the system settings from default ? If so which and what to ?
Do you have FNDC http://www.outbackpower.com/products/sy ... flexnet-dc

Tim
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.

rpbancroft
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Re: Configuring generator to fully charge batteries

Post by rpbancroft » Mon Jan 14, 2019 12:43 pm

Hey Tim,

If I remember correctly, I have only changed the following in the Mate3s: Settings > Inverter > AC Input and Current Limit (modified generator amperage in two places). I believe I also would have made changes in the "Gen AC Input Mode and Limits" if I could. This was when I was trying to change how much amperage the generator would take (so that it wouldn't overload the circuit).

I am pretty sure I haven't changed anything else, aside from some system information when I had to have my Mate3s replaced due to a system malfunction. I've tried to stay somewhat hands off with most things because I know that I could damage my system by, for example, modifying battery voltages.

Yes, I believe I do have the FNDC, though I've never noticed an LCD screen on it before (from the description, I gather that perhaps the Mate3s actually is its LCD?). It is mounted to the right side of the Inverter.

~Ryan

Mike Curran
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My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
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- 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Mon Jan 14, 2019 1:56 pm

When you say that the generator stops charging, do you mean it shuts itself off, or what? Or, if it keeps running, what indication do you have that charging has stopped?
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

rpbancroft
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Re: Configuring generator to fully charge batteries

Post by rpbancroft » Mon Jan 14, 2019 2:03 pm

Mike Curran wrote:When you say that the generator stops charging, do you mean it shuts itself off, or what? Or, if it keeps running, what indication do you have that charging has stopped?
The generator keeps running, but it stops charging the batteries. It continues carrying house loads actively, but won't touch the batteries any more. I base this conclusion off of how hard the generator's working (so, how it sounds) and the battery-charge bar (the right bar on the battery line on the mate3s default screen), which shows at 0.0kW.

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Mon Jan 14, 2019 2:27 pm

We need to check your battery charge settings...

1st of all, can you describe your battery? Amp-hour rating (@ C20 rate - probably how it's spec'd) is most important, although type (flooded lead acid, AGM, etc.) is also important. If you post the manufacturer/model no. we can look up specs if they're not readily available to you. This info will to some extent determine charger settings for your inverter and FNDC, which is the device that tells you SOC (which indication could very well be out of whack if your installer didn't set it up when your batteries were fully charged).

Your charger settings are set through the Mate3s (link to manual):
http://outbackpower.com/downloads/docum ... de_web.pdf
Applicable instruction:
Screenshot_20190114-171258.jpg
FNDC settings (and indications) are also done through the Mate3s. Use Tim's link for info, here's an add'l maybe helpful link: http://outbackpower.com/downloads/docum ... p_note.pdf

For your (edit) 24V battery, some suggested starting points for charger settings would be absorb voltage (edit)29.4VDC, absorb time 3 hours minimum, end amps (an FNDC setting) 2% of your battery amp-hour rating.
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

rpbancroft
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Re: Configuring generator to fully charge batteries

Post by rpbancroft » Mon Jan 14, 2019 2:43 pm

Wow, thanks for the detailed steps and help! Okay, let me see what I can provide.

According to our house builder / installer, these are the batteries we have. We have eight (8) of them, split into two groups of four (4) wired in parallel (at least that's my understanding).

https://www.centennialbatteries.com/amf ... file_id/4/

I believe they run at 12V, or at least that's the voltage of our DC appliances as measured by a voltmeter. In case it matters, the incoming voltage from the panels is 24V. I don't yet understand how all of this relates, but I am confident in those numbers (to the extent I've experienced them, anyway).

I believe I've seen the setting to which you linked a photo mentioned in the mate3s before, and also in its documentation. I'll check on it tonight and post what information I find there here when I can.

As for your suggestion on settings, when you say 2% of the amp hour rating, is that the 100% amp hour rating of all batteries combined (so in this case, that'd be 260*8*.02), or something else? Also, where is the absorb time set? I assume in a related space, but on a page within the settings different from the image you linked?

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Mon Jan 14, 2019 3:30 pm

Since you have a 24 volt inverter, your battery must be wired for 24 volts, with one of your 2 parallel banks tapped for your 12 volt loads, like this
1547508008264500695136.jpg
If that is the way it's wired then the amp-hour rate to use would be 2% of 270 (the C20 rate for your battery, per your mfr. link) ×4 = ~22A.

Absorb time is set in three (!) places, your FX3524, your FM80, and your FNDC. All can be set from your Mate3s. See the manual link in my earlier post.

As maybe you've already concluded, it'd be helpful for you if you could find someone local who has experience with Outback equipment, otherwise it's gonna be a learning curve :smile:

Edited multiplication sign at end of first paragraph.
Last edited by Mike Curran on Thu May 28, 2020 8:29 pm, edited 1 time in total.
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

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Re: Configuring generator to fully charge batteries

Post by DavzRVPort » Mon Jan 14, 2019 4:09 pm

I suspect if the generator is not a good one, once the batteries get charged so far (with only a moderate load) the generators' power is getting out of the acceptable ranges either on volts or frequency. Especially if it's set to the defaults. I used to experience this when my capacitor on the genny was going bad. You could check the error logs and see if this is the case. JMHO

rpbancroft
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Re: Configuring generator to fully charge batteries

Post by rpbancroft » Tue Jan 15, 2019 8:21 am

Hey Mike, surely they must be wired in that manner if they're working at all, right? Just to be sure, I'll try to verify that tonight.

I hear you on the learning curve, been riding it for a while now (just haven't had to deal with battery configs yet). It's just the kind I believe I need to experience, though, since I own this equipment now, and I'm too poor to call someone over every time I have a question. :)

And, just to say, I am SO GLAD I'm discovering this now, "only" 5 months into owning this system. I suspect these misconfigs have probably already shortened the life of our system, but hopefully, if we correct them now, the life-span shortening will be significantly minimized.

Do you by chance have a resource that explains why the amp hour rate is 2% of only four of the batteries' total amp hours, rather than all 8 of them? Also, why would I use the 270 rate rather than the 260? What do the "10hr" and "20hr" things mean? Maybe I'll try googling "using AGM batteries in an outback system" or something to try to get a comprehensive overview, unless something authoritative is already known?

Okay, I gathered all of the info I thought might be relevant last night (pretty much looked for anything that said "battery" in the config menus on the mate3s), and also read through the resource you linked. It turns out that, in Battery Setup, "Battery Ah" was left at its default of 400. I assume this is hugely wrong, and probably at least one source of the problem(s). What should I change it to? Also, on this same page, "Charged Voltage" is set to 28.6, "Charged Return Amps" is set to 8.0 (is this the "~22A" you mentioned above?), "Charge Factor" is set to 94%, and "Time" is set to 1 Minute. I assume more of these need to change? Is this by chance the primary source of the problem? Sure sounds like it could be after reading the resource you provided.

As for other info (providing current configs; each setting is separated by a '|' character):
  • In Settings > Battery Monitor > Relay Set Points: Voltage: High 14.0 VDC Low 12.0 VDC | SOC: High 0% Low 0% | Delay: High 1 Low 1 Minutes
  • In Settings > Inverter > Low Battery: Cut-Out Voltage 21.0 VDC | Cut-In Voltage 25.0 VDC
  • In Settings > Inverter > Battery Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC Time 1.0 | Re-Float Voltage 25.0 VDC | Re-Bulk Voltage 24.0 VDC
  • In Settings > System > System Information (I configured some of this, since it was required when I had to replace the Mate3s): Type Off Grid | Array Wattage 1830 | Gen kW Rating 3.6 | Max Inverter kW 3.5 | Nominal Voltage 24 | Battery Ah 1040 | Gen Type AC | Max Charger kW 2.1
  • In Settings > Charge Controller > Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC | ReBulk Voltage 24.0 VDC | Current Limit 80.0 A Absorb End Amps 0
What all do you recommend I modify? Do you need any other information to determine this? Just for reference, we have six 305W solar panels. Also, what here is dangerous to modify?
DavzRVPort wrote:I suspect if the generator is not a good one, once the batteries get charged so far (with only a moderate load) the generators' power is getting out of the acceptable ranges either on volts or frequency. Especially if it's set to the defaults. I used to experience this when my capacitor on the genny was going bad. You could check the error logs and see if this is the case. JMHO
Thanks for these thoughts! I don't know much about generators, so I can't say for sure whether or not ours is good. It's a Westinghouse WGEN3600DF, and it's an open-frame generator. It's only about 4 months old. Not sure on frequency, but, just watching the incoming voltage as reported by the mate, it seems to swing between about 115V and 122V or so. I haven't sat there and watched it for a long while, though. It seems to run pretty smoothly after it warms up, though.

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Tue Jan 15, 2019 9:38 am

rpbancroft wrote: And, just to say, I am SO GLAD I'm discovering this now, "only" 5 months into owning this system. I suspect these misconfigs have probably already shortened the life of our system, but hopefully, if we correct them now, the life-span shortening will be significantly minimized.
There's a saying that your first set of batteries becomes a sacrifice to the learning gods...hopefully, not always true.
rpbancroft wrote:Do you by chance have a resource that explains why the amp hour rate is 2% of only four of the batteries' total amp hours, rather than all 8 of them? Also, why would I use the 270 rate rather than the 260? What do the "10hr" and "20hr" things mean? Maybe I'll try googling "using AGM batteries in an outback system" or something to try to get a comprehensive overview, unless something authoritative is already known?
At the risk of overwhelming you with tech reading material, here's a good resource for understanding renewable batteries:
http://rollsbattery.com/wp-content/uplo ... Manual.pdf The 2% comes from page 11 of the Rolls manual, but that applies to FLA (flooded lead acid) batteries, not yours - my mistake. 270 vs. 260 probably not a big difference but most charging parameters are spec'd using the C20 rate. These numbers give the amp-hours your battery will deliver if discharged from full down to 0% SOC over the rate hour (C20 = 20 hour rate, C10 = 10 hour rate) specified. See page 7 of the Rolls manual for a description of why only 4 batteries figure into the total amp-hour capacity for your battery setup.
rpbancroft wrote:Okay, I gathered all of the info I thought might be relevant last night (pretty much looked for anything that said "battery" in the config menus on the mate3s), and also read through the resource you linked. It turns out that, in Battery Setup, "Battery Ah" was left at its default of 400. I assume this is hugely wrong, and probably at least one source of the problem(s). What should I change it to?
Change it to 4x(edited mult. sign)270=1080.
rpbancroft wrote: Also, on this same page, "Charged Voltage" is set to 28.6, "Charged Return Amps" is set to 8.0 (is this the "~22A" you mentioned above?), "Charge Factor" is set to 94%, and "Time" is set to 1 Minute. I assume more of these need to change?
The graph for your battery is harder for me to interpret but it does give the info you need...
Screenshot_20190115-120406.jpg
There are 2 sets of data shown here, one (upper) is voltage and other (lower) is current, over a charging cycle. Charged voltage is given by 2.45V/Cell = 29.2 volts (instead of 28.6), your return amps setting of 8 amps is right on based on Rolls' AGM chart on page 24 (can't figure from your battery chart :?: ), charge factor is okay, charge time seems low, it should be at least 2 hours, 1 minute is too short in a cycling/off grid application like yours.
rpbancroft wrote: As for other info (providing current configs; each setting is separated by a '|' character):
  • In Settings > Battery Monitor > Relay Set Points: Voltage: High 14.0 VDC Low 12.0 VDC | SOC: High 0% Low 0% | Delay: High 1 Low 1 MinutesNA
  • In Settings > Inverter > Low Battery: Cut-Out Voltage 21.0 VDC | Cut-In Voltage 25.0 VDCThis sets where your inverters shut down for low battery (cut out) and restart when battery is recharging (cut in) - probably okay
  • In Settings > Inverter > Battery Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC Time 1.0 | Re-Float Voltage 25.0 VDC | Re-Bulk Voltage 24.0 VDCChange absorb volts to 29.4, time to 2; the rest are okay
  • In Settings > System > System Information (I configured some of this, since it was required when I had to replace the Mate3s): Type Off Grid | Array Wattage 1830 | Gen kW Rating 3.6 | Max Inverter kW 3.5 | Nominal Voltage 24 | Battery Ah 1040 | Gen Type AC | Max Charger kW 2.1
  • In Settings > Charge Controller > Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC | ReBulk Voltage 24.0 VDC | Current Limit 80.0 A Absorb End Amps 0Absorb voltage should be 29.4 (0.2V higher than inverter's setting), End amps should be 8
    What all do you recommend I modify? Do you need any other information to determine this? Just for reference, we have six 305W solar panels. Also, what here is dangerous to modify?
It's all dangerous :grin: Seriously, you're not far off, except for that 400AH battery capacity setting. Check in again after you've had enough absorb time :lol:
Last edited by Mike Curran on Thu May 28, 2020 8:33 pm, edited 1 time in total.
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

rpbancroft
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Re: Configuring generator to fully charge batteries

Post by rpbancroft » Tue Jan 15, 2019 10:19 am

You are so helpful, I can't thank you enough!
Mike Curran wrote:There's a saying that your first set of batteries becomes a sacrifice to the learning gods...hopefully, not always true.
Wow, I kinda wish I'd been introduced to the off-gridders quote book earlier in this process. :) Maybe I'll start compiling one to share on our website once we're ready to go with that. Guess I'll just have to do my best and hope.
Mike Curran wrote:At the risk of overwhelming you with tech reading material, here's a good resource for understanding renewable batteries:
http://rollsbattery.com/wp-content/uplo ... Manual.pdf The 2% comes from page 11 of the Rolls manual, but that applies to FLA (flooded lead acid) batteries, not yours - my mistake. 270 vs. 260 probably not a big difference but most charging parameters are spec'd using the C20 rate. These numbers give the amp-hours your battery will deliver if discharged from full down to 0% SOC over the rate hour (C20 = 20 hour rate, C10 = 10 hour rate) specified. See page 7 of the Rolls manual for a description of why only 4 batteries figure into the total amp-hour capacity for your battery setup.
Haha, this process has been nothing if not overwhelming; if you'd said it suddenly wouldn't be, I'd be shocked! I'll just read each line the apparently requisite 10 times to start to understand it, and then, from there, I can start actually understanding it with subsequent re-reads.
Mike Curran wrote:Change it to 4×270=1080.
Okay, that fits what I'd expect. Will do!
Mike Curran wrote:The graph for your battery is harder for me to interpret but it does give the info you need... There are 2 sets of data shown here, one (upper) is voltage and other (lower) is current, over a charging cycle. Charged voltage is given by 2.45V/Cell = 29.2 volts (instead of 28.6), your return amps setting of 8 amps is right on based on Rolls' AGM chart on page 24 (can't figure from your battery chart :?: ), charge factor is okay, charge time seems low, it should be at least 2 hours, 1 minute is too short in a cycling/off grid application like yours.
Great, I'll change them! I'm slowly starting to understand this better. Wish I had some idea of why my battery chart was lacking... I didn't choose these batteries, so I had absolutely no background in them when we received them. Definitely makes me think it's best not to buy a system like this blind ever again.
rpbancroft wrote: As for other info (providing current configs; each setting is separated by a '|' character):
  • In Settings > Battery Monitor > Relay Set Points: Voltage: High 14.0 VDC Low 12.0 VDC | SOC: High 0% Low 0% | Delay: High 1 Low 1 MinutesNA
  • In Settings > Inverter > Low Battery: Cut-Out Voltage 21.0 VDC | Cut-In Voltage 25.0 VDCThis sets where your inverters shut down for low battery (cut out) and restart when battery is recharging (cut in) - probably okay
  • In Settings > Inverter > Battery Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC Time 1.0 | Re-Float Voltage 25.0 VDC | Re-Bulk Voltage 24.0 VDCChange absorb volts to 29.4, time to 2; the rest are okay
  • In Settings > System > System Information (I configured some of this, since it was required when I had to replace the Mate3s): Type Off Grid | Array Wattage 1830 | Gen kW Rating 3.6 | Max Inverter kW 3.5 | Nominal Voltage 24 | Battery Ah 1040 | Gen Type AC | Max Charger kW 2.1
  • In Settings > Charge Controller > Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC | ReBulk Voltage 24.0 VDC | Current Limit 80.0 A Absorb End Amps 0Absorb voltage should be 29.4 (0.2V higher than inverter's setting), End amps should be 8
    What all do you recommend I modify? Do you need any other information to determine this? Just for reference, we have six 305W solar panels. Also, what here is dangerous to modify?
Thanks a bunch for the in-line edits. I'll make those, too. Oh, one question about those, I noticed that, in the inverter section, you set the volts to 29.4, and then, in the charge controller, you also set it to 29.4 volts, but then said beside it that I should make this 0.2V higher than the inverter settings. Does this mean the inverter should be 29.2, or 29.4 and the CC 29.6?
Mike Curran wrote:It's all dangerous :grin: Seriously, you're not far off, except for that 400AH battery capacity setting. Check in again after you've had enough absorb time :lol:
That's what I'd always heard about the battery settings! And that's exactly why I basically ignored them, concerned that I'd screw something up, never thinking that maybe my installer / system provider might have done the screwing up from the get go. It won't be long till I'll have an opportunity to test this, since we seem to be in phase of existence where clouds are far more abundant than sunshine.

Oh, and one last question about initial configs, I don't seem to have located the place where that ~22A setting you mentioned before should be set. Has that been addressed in the previous mods you suggested, or is it something else I need to change? And where might I find it in the system settings?

Finally, Is there a best time to make all of these changes? Is it better while charging, discharging, or something else? Fortunately, today we have sun (finally; it's been almost a week), so there's a great chance we'll reach 100% SoC.

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Re: Configuring generator to fully charge batteries

Post by David LeBow » Tue Jan 15, 2019 11:22 am

rpbancroft wrote:You are so helpful, I can't thank you enough!
Mike's a "Forum Czar" for a reason!

Thanks, Mike for all the help you provide on the forum!

David
David LeBow
Sr. Director, Software Engineering


Alpha Technologies Inc. / OutBack Power Technologies
3767 Alpha Way Bellingham WA 98226 USA
http://www.alpha.com

Mike Curran
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Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Tue Jan 15, 2019 11:41 am

Oh, one question about those, I noticed that, in the inverter section, you set the volts to 29.4, and then, in the charge controller, you also set it to 29.4 volts, but then said beside it that I should make this 0.2V higher than the inverter settings. Does this mean the inverter should be 29.2, or 29.4 and the CC 29.6?
Sorry, thought I fixed that... too much detail...Anyway, make inverter 29.2 and FM80 29.4.
Oh, and one last question about initial configs, I don't seem to have located the place where that ~22A setting you mentioned before should be set. Has that been addressed in the previous mods you suggested, or is it something else I need to change? And where might I find it in the system settings?
That's charged amps or return amps, same thing, but I was mistaken at 22, should be 8 amps and you said that's what it's set for
"Charged Return Amps" is set to 8.0 (is this the "~22A" you mentioned above?)
so all good, no need to change anything. Fyi, here's where it's at in Mate3s (2 places, charge controller and FNDC)
Screenshot_20190115-143757.jpg
Screenshot_20190115-143922.jpg
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

blackswan555
Forum Emperor
Posts: 2637
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My RE system: Other peoples, VFX "E" versions, FLA`s, Generators.
Location: Ibiza Spain,

Re: Configuring generator to fully charge batteries

Post by blackswan555 » Tue Jan 15, 2019 1:06 pm

There are a couple of mistakes in the above,
[*]In Settings > Inverter > Battery Charger: Absorb Voltage 28.8 VDC Time 1.0 | Float Voltage 27.2 VDC Time 1.0
Voltage is a bit low as has been pointed out, Absorb time of 1hr is way to short, more like 4hrs, float time of 1 hr is total waste of fuel, set to 0
In Settings > Charge Controller > Charger: Absorb Voltage 28.8 VDC Time 1.0 |
Again, way to short, probably 5 hrs

End amps, Do not use,,,,,,If you think you want to use it, do not believe the 2%, Measure it yourself and beware it will change with load, temp, bat condition and what colour socks you have on,

My advice, Disable FNDC and just use it as battery monitor for now, Set absorb time for gen to 4 hrs, Solar 5hrs, Watch your SGs for a while and tweak times as necessary, Calibrate the FNDC to match SGs, When you are happy the FNDC agrees with the SG (Maybe never,,,,,,, Well not for more than a few weeks,,,) Then think about letting it "drive"

Tim
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Tue Jan 15, 2019 3:25 pm

Tim - All due respect, I based my recommendations for absorb time, voltage, and end amps on the battery manufacturer's charge graph, which was attached to my post. - Mike
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

rpbancroft
Forum Member
Posts: 22
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My RE system: VFXR3524A inverter, FlexMax 80 charge controller, Mate3s

Re: Configuring generator to fully charge batteries

Post by rpbancroft » Wed Jan 16, 2019 9:52 am

Tim, thanks for the additional details / thoughts! What do the absorb and float times do, by the way? What makes the float time in the inverter a waste of fuel in your estimation? I only have an incredibly basic understanding of float; basically, it means the batteries are fully charged and not really receiving more power, or something. Probably an incorrect basic understanding. :)

Also, what's an "SG"?

I made many of the original edits Mike suggested around 4:10pm, 1/15/19. One notable thing, the SoC was at 90% this morning after a full 100% charge from the sun yesterday; it only lost 10% over about 14 hours of darkness. That's the highest I've seen it remain, by a fair margin, after a full winter night (granted it wasn't super cold, so I doubt the heat tape ran all night). Would changing the battery Ah from 400 to 1080 be the reason for that?

We should have plenty of cloudy days over the next few days, so I should have a solid opportunity to see if the generator is able to charge up the system to "max" no matter how deeply the batteries discharge.

Given that our system was apparently misconfigured from top to bottom, is there anything else you all would recommend I check on? Hoping to avoid any other nasty surprises.

Thanks so very much!

~Ryan

JRHill
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Re: Configuring generator to fully charge batteries

Post by JRHill » Wed Jan 16, 2019 10:36 am

This is an interesting thread. Actually, I read all the conversations regarding the charging parameters of flooded batteries 'cause I've learned a bunch and, consequently, extended battery life and saved $$. A couple of things popped out at me in this thread that I thought would be brought out and they are an extension to charging parameters. Forgive me if it was and I missed them:

1) Multiple battery strings. At two 24v strings you are relatively OK from my understanding but I only have experience with one string. Each string will age and work differently over time 'cause they are unique. Consequently, they will charge differently and the *FX* / *FM* doesn't know or can't control what gets to each bank for full charges regardless of what the Mate* displays.

2) If you load (substantially) one or two batteries in a string, externally, the *FX* / *FM* doesn't care as it's doing the whole string so some get more and some less. And if you have multiple stings and one of them has a side load then this gets to be an incalculable hair ball. About the best you can do is rotate the 12v loads around the banks or rotate the batteries.

input?

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Wed Jan 16, 2019 12:28 pm

Jim - I agree, more than 2 batteries in parallel is problematic for just the reasons you've cited - over time, small differences in each battery's resistance will lead to differences in charging current and eventually some will fail before others. Ryan is kind of stuck with his 24V setup unless he wants to drastically reduce his amphour capacity by just putting 2 - 12V batteries in series, or maybe 2 × 2 in series (instead of the 4 × 2 setup he has). That would leave him with 4 extra batteries laying around and this may not be practical for him, being off grid. So the better alternative, as you suggest, is to closely monitor each battery, maybe rotate them occasionally. So much for set it and forget it. :sad: Of course no off grid system is really set it forget it.

From the posts I've seen, to me it seems there are more than a few installers out there who don't have a clue as to how batteries work - they can wire up a system, but not much beyond that. Maybe others have had better experiences...
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Wed Jan 16, 2019 5:17 pm

What do the absorb and float times do, by the way? What makes the float time in the inverter a waste of fuel in your estimation? I only have an incredibly basic understanding of float; basically, it means the batteries are fully charged and not really receiving more power, or something. Probably an incorrect basic understanding. :)

Also, what's an "SG"?

Would changing the battery Ah from 400 to 1080 be the reason for tha
During a charge cycle, the charger brings your battery up to the absorb voltage by supplying as much current as it will take. During this phase your battery regains about 80% of its charge. After it reaches absorb voltage, the charger maintains it there for the absorb time, during which the final 20% of charging occurs (you can find a description of this process on page 10 of the Rolls battery manual).

Float is just keeping your battery at its optimum operating voltage. If you have plenty of sunshine and your loads aren't dragging your battery voltage down, setting some time for float isn't a bad idea. But if you're on the edge, solar capacity vs. load-wise, then Tim's right, let your batteries do their job and then recharge them with your genny/solar as needed. Otherwise you're using generator power to maintain voltage at float (wasting fuel) when it should really only be used to recharge your battery, not maintain float.

SG stands for specific gravity (density) of the acid in your battery. Since you have AGM batteries, SG isn't applicable or measurable - there's no accessible liquid acid in your batteries. It's present ("Absorbed") in the Absorbed Glass Mat in your AGM batteries. In any case, SG is the very best method for judging the state of charge of a flooded lead acid (FLA) battery, defined as the weight in grams of one milliliter of battery acid. The denser the acid, the higher the state of charge.

My bet is yes, correcting the battery capacity to 1080Ah is probably why your battery is now charging up higher. You might want to try upping the absorb time to Tim's suggested 4 hours to see if that'll get you to 100% SOC. I believe (correct me if I'm wrong, somebody) AGM batteries are much more tolerant of overcharge than FLA's but I would experiment to get the right absorb time. Once you've done an extended absorb and you're pretty sure your battery is fully charged (I don't know how to judge this for AGM's, hope someone chimes in) unplug the ethernet cable connecting your FNDC to your Hub, then replug it in. This sets/calibrates the FNDC to an accurate 100% SOC but beware, this will drift over time and eventually the FNDC SOC indication will not be accurate. You'll have to repeat the process to get it "re-calibrated".

This FNDC stuff probably seems pretty mysterious. In my grid-connected system, I find it to be useful especially since I seldom discharge my batteries - it tends to stay accurate. However, for your off-grid system, where you're daily discharging and recharging your battery, it can quickly become problematic, leading you to think maybe your battery is fully charged when it really isn't. I think that's why Tim is recommending you disconnect it. He has more experience with off grid systems than I do, and others have recommended the same, especially when people are having trouble keeping their batteries charged with an operating FNDC dictating the charge regimen. Again, hoping others will chime in.

- Mike
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

SandyP
Forum Guru
Posts: 423
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My RE system: 8 x 190W 24V Suntech panels (4 strings of 2) July 2011
4 x 325W 24V Suntech panels (2 strings of 2) added Sept2018
Mate2
Outback FM60 MPPT (max output lowered to 55amps)
12 x 2V Hoppecke GEL 660 Ah C100 - 24V System
Outback VFX3024 Inverter/Charger
Victron BMV-602s
Honda 5.5kW Genset
Location: Victoria, Australia

Re: Configuring generator to fully charge batteries

Post by SandyP » Wed Jan 16, 2019 11:54 pm

Mike Curran wrote:Tim - All due respect, I based my recommendations for absorb time, voltage, and end amps on the battery manufacturer's charge graph, which was attached to my post. - Mike
It sure is a strange battery charging graph, and something the the Outback FM charge controllers cannot exactly follow i.e :
Stage 1 : indicates constant current during Bulk charging - cannot see this happening (maybe using the inverter's charger)
Stage 2 : a two hour charge period at the end of the bulk phase at a slightly lower charge rate
Stage 3 : Absorb charge phase (no specific time period shown but seems to be 2 hours)
Stage 4 : A time limited float (or just a time limited stage but not float based on what they say the float voltage should be?) - maybe via the FX inverter but not via the FM?

So not batteries typically used for solar applications.

JRHill
Forum Czar
Posts: 929
Joined: Thu Feb 17, 2011 11:12 am
My RE system: VFX 3648, FM80, 3k panels, Mate3, FNDC (retired), 8ea L16 mixed. Wonderful wife.

Re: Configuring generator to fully charge batteries

Post by JRHill » Thu Jan 17, 2019 1:40 am

Mike Curran wrote:Ryan is kind of stuck with his 24V setup unless he wants to drastically reduce his amphour capacity by just putting 2 - 12V batteries in series, or maybe 2 × 2 in series (instead of the 4 × 2 setup he has)....
To clarify, in 2), I was referring to powering 12vdc appliances by tapping into part of a higher voltage string. I've cheated to make 12vdc for a relay by tapping across just 2 batteries in a string of 8 but the load was a few milliamps and only when tripped. But appliances? That's what's really problematic to me.

Mike Curran
Forum Emperor
Posts: 1809
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Configuring generator to fully charge batteries

Post by Mike Curran » Thu Jan 17, 2019 5:31 am

It sure is a strange battery charging graph
I agree, it's a confusing chart. I like the one Rolls has for their AGM batteries, easier to understand:
Screenshot_20190117-082751.jpg
Voltage in red, current in blue.

Probably useful for any AGM battery...
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

SandyP
Forum Guru
Posts: 423
Joined: Tue Jun 21, 2011 4:44 am
My RE system: 8 x 190W 24V Suntech panels (4 strings of 2) July 2011
4 x 325W 24V Suntech panels (2 strings of 2) added Sept2018
Mate2
Outback FM60 MPPT (max output lowered to 55amps)
12 x 2V Hoppecke GEL 660 Ah C100 - 24V System
Outback VFX3024 Inverter/Charger
Victron BMV-602s
Honda 5.5kW Genset
Location: Victoria, Australia

Re: Configuring generator to fully charge batteries

Post by SandyP » Thu Jan 17, 2019 2:23 pm

Mike Curran wrote:
It sure is a strange battery charging graph
I agree, it's a confusing chart. I like the one Rolls has for their AGM batteries, easier to understand:

Probably useful for any AGM battery...
Good to see they show float starting when the charging amps has dropped to ~0.7% C20.
I have found that for my GEL batteries 0.5% C20 seems to correlate to being fully charged and as such I use this as my "end amps" setting in the FM60.
With the cabin not in use my battery bank is at ~95% SoC in the morning this setting results in a 1.75 hour absorb charging phase.

rpbancroft
Forum Member
Posts: 22
Joined: Mon Oct 29, 2018 10:41 am
My RE system: VFXR3524A inverter, FlexMax 80 charge controller, Mate3s

Re: Configuring generator to fully charge batteries

Post by rpbancroft » Tue Jan 22, 2019 3:33 pm

Oops, sorry, I ended up falling ill there, so I'm trying to catch back up on things.

I hope to address many of the comments here soon, but I had a possibly related question that's considerably more urgent. We have had this new config in place for a while now, and in some ways it's great. However, we've had a carbon monoxide detector in place for a while now, which has never gone off, even while using our unvented propane heater. However, it has gone off twice in the past 30 hours. My wife did some research that revealed that hydrogen gas vented by AGM (and other SLA) batteries can cause false positives in CO detectors. This is particularly concerning because apparently this hydrogen gas in sufficient concentrations is also explosive. We're trying to figure out how likely this is to be related to our batteries. Does anyone have any experience with this?

Edit: I found this resource: https://batteriesbyfisher.com/agm-batteries

It mentions the following: "At high overcharge currents, electrolysis of water occurs, expelling hydrogen and oxygen gas through the batteryÔÇÖs valves. Care must be taken to prevent short circuits and rapid charging. Constant-voltage charging is the usual, most efficient and fastest charging method for VRLA batteries, although other methods can be used. VRLA batteries may be continually ÔÇ£floatÔÇØ charged at around 2.35 volts per cell at 25 ┬░C. Some designs can be fast charged (1 hour) at high rates. Sustained charging at 2.7 V per cell will damage the cells. Constant-current overcharging at high rates (rates faster than restoring the rated capacity in three hours) will exceed the capacity of the cell to recombine hydrogen and oxygen."

Are the changes we made to the voltages within this tolerance range? I'm unsure how to understand that since the amounts I was working with were more like "28.8 to 29.4".

Thanks so much!

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