sulfation?

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Megunticook
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My RE system: 6.4 kW solar array (21 QCell 305 panels in strings of 3)
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8x6v Rolls-Surette 550 FLA batteries, 428AH
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sulfation?

Post by Megunticook » Wed Sep 04, 2019 4:23 am

During my routine battery check yesterday I noticed a light gray material in between some of the plates. Is this sulfation?

S.G. ranged from 1.280-1.295 (that's a bit higher than normal, usually more like 1.275-1.290). The electrolyte level was a bit down (roughly 1" from the bottom of the filler tubes), so I added enough water to bring the level to within 1/2" of the tubes. No plates were exposed. I did a 1-1/2 hour equalization at 62.2 V and I "think" it removed some of the gray material but that's just my casual observation. I still see some. Should I do a three hour EQ?

These are Rolls S-550 FLA batteries, going on two years old now, and mostly sit fully charged in my grid-tie system. I try to "exercise" them every couple months by discharging to roughly 75% SOC and recharging with the solar array, and about every 6 months or so they get an EQ.

I'm wondering if I need to do more. Discharge more deeply, more often? Make sure they get a heavy current when charging? Longer EQ?

I'll see if I can get a picture. Maybe I'm worrying too much. But I'd like to remove all that gray stuff from the plates ASAP.

My battery manual says that these batteries have a "break-in" period of 60-90 cycles, during which time their capacity will actually increase. I've only cycled them 9 times. Maybe I should just work them a lot harder.

Any and all advice welcome
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raysun
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Re: sulfation?

Post by raysun » Wed Sep 04, 2019 6:33 am

From the description of the material, it sounds like lead sulfate crystals.

The typical sulfation of a lead-acid battery is almost always the result of cronic undercharging, pretty much the opposite of the described situation.

From the description of usage, it sounds like the battery is used in float (backup) service rather than cyclic service. Batteries purpose-built for float service have a different structure, a different charging profile, and about a 5 year life expectancy.

Someone with more FLA practical experience can provide a better diagnosis and prescription, but I'd think this type of precipitation should be reversible. It may take a very low-current charge for a very long cycle - on the order of 24 hours.

It makes anecdotal sense that a battery made for cyclic use should be cycled regularly.

Rolls may have some guidance on changes to the maintenance routine.

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Megunticook
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Joined: Fri Sep 29, 2017 4:08 am
My RE system: 6.4 kW solar array (21 QCell 305 panels in strings of 3)
GS8048A FLEXpower Radian (Radian 8048A, 2 FlexMax 80 cc's, Mate 3s, FlexNet DC, Hub)
8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
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Re: sulfation?

Post by Megunticook » Wed Sep 04, 2019 6:41 am

Thanks. I don't believe there's chronic undercharging happening, based on my s.g. readings, unless I'm missing something.

On the other hand, they do spend 95% of their time in float mode, with a daily absorption of about an hour each morning.

Agreed that maybe these particular batteries aren't ideal for backup application--but perhaps if I "exercise" them regularly I can get a decent service life out of them.
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raysun
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Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: sulfation?

Post by raysun » Wed Sep 04, 2019 6:54 am

I didn't think they were undercharged either, rather underused.

Hard sulfation (the irreversible coating of the lead plates) caused by undercharging is not likely the problem.

Soft sulfation (the reversible formation of lead-sulfate crystals) should be "treatable".

If I owned a race horse, I'd expect I'd need to run it regularly. For deep cycle batteries, I'd expect cycling them regularly would be beneficial to their long-term health. If nothing else, it would help keep the electrolyte from stratifying, and perhaps reduce the risk of grid corrosion.

Maybe a practical strategy would be to discharge the battery to its "sweet spot" for maximum cycle life (maybe 20-25% depth of discharge) regularly, perhaps once a week.

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Megunticook
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8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
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Re: sulfation?

Post by Megunticook » Wed Sep 04, 2019 7:02 am

I think your once-a-week prescription is probably about right for these batteries.

After sunset I'll drop the grid and see if I can pull them down to 70% SOC by morning, then charge them in the morning.
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Megunticook
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GS8048A FLEXpower Radian (Radian 8048A, 2 FlexMax 80 cc's, Mate 3s, FlexNet DC, Hub)
8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
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Re: sulfation?

Post by Megunticook » Wed Sep 04, 2019 8:39 am

Here's a photo--not great but the best I could do:

Image

Is that gray stuff sulfation?
https://sunnypower.org

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
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Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: sulfation?

Post by raysun » Wed Sep 04, 2019 8:53 am

The little specks resting randomly on top of the plates?

I doesn't fit the visual description of typical battery sulfation. It does fit the visual description of an insoluble precipitate- lead sulfate crystals. Without chemical analysis, however, this is conjecture.

There is a way to get a better ID. Continue to do an Equalize charge for an extended period 8 - 24 hours. If the specks are gone, it's likely lead sulfate precipitate.

If they hang around, stop eating saltines over your open battery vents. ;)

In any event, the sulfation of your concern would be a permanent sheet of lead sulfate bonded to the lead plates, taking them out of the system in regards to battery capacity. What you are looking at doesn't appear to be that.

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Megunticook
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My RE system: 6.4 kW solar array (21 QCell 305 panels in strings of 3)
GS8048A FLEXpower Radian (Radian 8048A, 2 FlexMax 80 cc's, Mate 3s, FlexNet DC, Hub)
8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
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Re: sulfation?

Post by Megunticook » Wed Sep 04, 2019 8:59 am

What I'm seeing isn't so much specks as a sort of light-gray colored material sandwiched between the plates...
https://sunnypower.org

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Megunticook
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Posts: 236
Joined: Fri Sep 29, 2017 4:08 am
My RE system: 6.4 kW solar array (21 QCell 305 panels in strings of 3)
GS8048A FLEXpower Radian (Radian 8048A, 2 FlexMax 80 cc's, Mate 3s, FlexNet DC, Hub)
8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
Contact:

Re: sulfation?

Post by Megunticook » Wed Sep 04, 2019 10:09 am

I wonder if my battery construction ignorance is in play here. Is the gray stuff in between supposed to be there to separate plates? Thing is, it's not consistent as I look in different cells...that's why I thought it was an accumulation of some sort.
https://sunnypower.org

raysun
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Posts: 1247
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)
Honda EU7000is gas fuel generator

Re: sulfation?

Post by raysun » Wed Sep 04, 2019 10:14 am

My small screen isn't displaying what you're seeing. From your description, then yes, it can be labelled sulfation. Now, whether it's hard sulfation (unlikely), or soft sulfation (more likely), will be borne out by a good Equalization charge, I'd think.

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Re: sulfation?

Post by oldbrowhnat » Wed Jan 08, 2020 9:37 pm

Interesting. I recently replaced my 4 x L16 on my backup system (VFX3524 + MATE) and was just running them for a bit every two or three weeks, not knowing that there is quite an extended break-in cycle. The lady I spoke with at Trojan said 50-75 cycles. No wonder they weren't working quite up to spec. I checked the SG yesterday and all cells were at 1.27 (two were just barely below) so no worries there.

I read somewhere recently but of course can't find it now, that the normal plate colour should be choc.brown and that grey indicated sulfation, but that simply can't be right! Mine looked pretty good. I did a 2-hr equalization today and the plates look like this:
IMG_5980.JPG
Haven't measured SG post-EQ yet. Will do that tomorrow, and switch to battery power for a couple of hours daily now to get them broken in, hopefully before we get a power outage of any severity. I have a 6kW Onan diesel genny as well, though, which I use to recharge the batteries and run the house during outages.

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Megunticook
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My RE system: 6.4 kW solar array (21 QCell 305 panels in strings of 3)
GS8048A FLEXpower Radian (Radian 8048A, 2 FlexMax 80 cc's, Mate 3s, FlexNet DC, Hub)
8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
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Re: sulfation?

Post by Megunticook » Thu Jan 09, 2020 3:56 am

I wonder if that gray stuff might be the insulating material that lies between plates?

You may need to pull them down for more than two hours but not sure what sort of loads you have. My research (and advice from Rolls and people on this forum) is that 70% SOC is a good target. That way when you kick off a charge cycle you're in the bulk charging phase rather than just absorption--you want a good strong current pushing in (but obviously not so much that the batteries overheat--check the Trojan specs on that).

I really need to get on a weekly schedule myself at this point. I'm not even halfway through the break-in period and it's been 2 years already.
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-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.
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Re: sulfation?

Post by JRHill » Thu Jan 09, 2020 11:37 am

I'd like to chime in but with my recent L16RE-B failures y'all would probably think "Dr. heal thyself".

About all I will add to this thread is my observation that everything FLA Battery is unpredictable. Each year the weather and solar charging are different. Its not the fault of the FM. It does what its programmed to do but the solar inputs are the limiting factor. And each battery bank (of the same production run) should be close to the same but in reality not necessarily so. The inverter charging may vary if manually controlled but could be solved with AGS (in place). But still, there are battery issues. Dang. All in all, a system should be operating at peak. Maybe not.

For the record of unpredictability above, our/my power use is low and usually not more that 4kWh/day. All loads are low with the largest inrush being from these: one EnergyStar fridge and two ES chest freezers, add in the evening the TV and satellite (electrical) overhead from DirecTV and HughesNet. But daily kWh charging to the batteries is more than 100% of usage. Stated again, 8+kwH in and 4kWh out. After all these years I am disappointed that the very capable input of the infrastructure is wasted on inefficient batteries. I heavily discharge batteries once a month. And I heavily recharge them as best I can at the same interval to address the issue above.

Living off grid is not for the non-technical and unskilled in things electrical unless you have a big wallet for a servicer close at hand. Ya don't fix issues in this stuff by pressing buttons.

Megunticook, I wish you can figure this out. A new bank sucks.

Best,
JRH

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Megunticook
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Joined: Fri Sep 29, 2017 4:08 am
My RE system: 6.4 kW solar array (21 QCell 305 panels in strings of 3)
GS8048A FLEXpower Radian (Radian 8048A, 2 FlexMax 80 cc's, Mate 3s, FlexNet DC, Hub)
8x6v Rolls-Surette 550 FLA batteries, 428AH
Location: Maine
Contact:

Re: sulfation?

Post by Megunticook » Thu Jan 09, 2020 12:39 pm

JRHill wrote:
Thu Jan 09, 2020 11:37 am
Megunticook, I wish you can figure this out. A new bank sucks
I think my bank is fine...unless I'm mistaken, I don't believe I have a serious sulfation problem after all. I think I was just getting confused by the material between the plates.

But I definitely should be using my batteries more often. I keep a pretty close eye on them though. Just need to be diligent in a weekly maintenance cycle.
https://sunnypower.org

JRHill
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Posts: 679
Joined: Thu Feb 17, 2011 11:12 am
My RE system: -House: FM 80, VFX 3648, FlexnetDC, FlexWare xformer, Mate 3 / Hub, WattPlot/, 2925w SunTech 195, Trojan L16RE-B Batteries. Backup 1: Honda EU7000is w/2 wire auto start via VFX aux, backup 2: 11kw Miller Bobcat;
-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.
Location: South central WA
Contact:

Re: sulfation?

Post by JRHill » Thu Jan 09, 2020 1:09 pm

Megunticook wrote:
Thu Jan 09, 2020 12:39 pm
JRHill wrote:
Thu Jan 09, 2020 11:37 am
Megunticook, I wish you can figure this out. A new bank sucks
But I definitely should be using my batteries more often. I keep a pretty close eye on them though. Just need to be diligent in a weekly maintenance cycle.
Draw heavy and charge heavy and then top them off as best as possible. I do it on a monthly basis, kind'a. Sigh, still I've had some failed batteries this time around. You know your system and you'll figure it out. When you do, please tell me. ;-)

JRHill
Forum Czar
Posts: 679
Joined: Thu Feb 17, 2011 11:12 am
My RE system: -House: FM 80, VFX 3648, FlexnetDC, FlexWare xformer, Mate 3 / Hub, WattPlot/, 2925w SunTech 195, Trojan L16RE-B Batteries. Backup 1: Honda EU7000is w/2 wire auto start via VFX aux, backup 2: 11kw Miller Bobcat;
-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.
Location: South central WA
Contact:

Re: sulfation?

Post by JRHill » Thu Jan 09, 2020 1:10 pm

JRHill wrote:
Thu Jan 09, 2020 1:09 pm
Megunticook wrote:
Thu Jan 09, 2020 12:39 pm
JRHill wrote:
Thu Jan 09, 2020 11:37 am
Megunticook, I wish you can figure this out. A new bank sucks
But I definitely should be using my batteries more often. I keep a pretty close eye on them though. Just need to be diligent in a weekly maintenance cycle.
Draw heavy and charge heavy and then top them off as best as possible. I do it on a monthly basis, kind'a when off season. Sigh, still I've had some failed batteries this time around. You know your system and you'll figure it out. When you do, please tell me. ;-)

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