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sulfation?

Posted: Wed Sep 04, 2019 4:23 am
by Megunticook
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

Re: sulfation?

Posted: Wed Sep 04, 2019 6:33 am
by raysun
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.

Re: sulfation?

Posted: Wed Sep 04, 2019 6:41 am
by Megunticook
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.

Re: sulfation?

Posted: Wed Sep 04, 2019 6:54 am
by raysun
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.

Re: sulfation?

Posted: Wed Sep 04, 2019 7:02 am
by Megunticook
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.

Re: sulfation?

Posted: Wed Sep 04, 2019 8:39 am
by Megunticook
Here's a photo--not great but the best I could do:

Image

Is that gray stuff sulfation?

Re: sulfation?

Posted: Wed Sep 04, 2019 8:53 am
by raysun
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.

Re: sulfation?

Posted: Wed Sep 04, 2019 8:59 am
by Megunticook
What I'm seeing isn't so much specks as a sort of light-gray colored material sandwiched between the plates...

Re: sulfation?

Posted: Wed Sep 04, 2019 10:09 am
by Megunticook
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.

Re: sulfation?

Posted: Wed Sep 04, 2019 10:14 am
by raysun
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.

Re: sulfation?

Posted: Wed Jan 08, 2020 9:37 pm
by oldbrowhnat
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.

Re: sulfation?

Posted: Thu Jan 09, 2020 3:56 am
by Megunticook
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.

Re: sulfation?

Posted: Thu Jan 09, 2020 11:37 am
by JRHill
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

Re: sulfation?

Posted: Thu Jan 09, 2020 12:39 pm
by Megunticook
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.

Re: sulfation?

Posted: Thu Jan 09, 2020 1:09 pm
by JRHill
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. ;-)

Re: sulfation?

Posted: Thu Jan 09, 2020 1:10 pm
by JRHill
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. ;-)

Re: sulfation?

Posted: Sat Feb 01, 2020 10:17 am
by Sparkey
I would suggest running equalization for short periods several times weekly or bi-weekly depending on their use for 12+ minutes instead of waiting the month to 6 weeks then beating on the plates for several hours.. This weekly electrolyte stir and plate cleaning would simulate a stress use on batteries that do not get a regular workout and help to keep the plates clean..

Re: sulfation?

Posted: Sat Feb 01, 2020 10:49 am
by raysun
Sparkey wrote:
Sat Feb 01, 2020 10:17 am
I would suggest running equalization for short periods several times weekly or bi-weekly depending on their use for 12+ minutes instead of waiting the month to 6 weeks then beating on the plates for several hours.. This weekly electrolyte stir and plate cleaning would simulate a stress use on batteries that do not get a regular workout and help to keep the plates clean..
The only concern I'd have would be the inevitable grid corrosion caused by the controlled overcharge voltage of an EQ charge.

Rolls recommends EQ only when cell SG varies by more than 0.030. This makes EQ a remedial operation rather than a normal maintenance step.

I wonder if the same result could be achieved by an extended Absorb cycle. Granted, that is, that Absorb voltage is lower, and easier on the internals, than EQ.

Re: sulfation?

Posted: Sat Feb 01, 2020 11:33 am
by Sparkey
That's the thing isn't it, the difference between running absorb at 58.8v for extra hours as opposed to running 64v for 12 minutes as opposed to trickling at 54v which would not prevent crystal growth or stratification.. No matter what the lead plates will wear or decay loosing around 10% capacity even with perfect cycling because HCL electrolyte is an acid and Lead is a metal.. That is why I suggest 12 minutes of the EQ voltage once a week for standby batteries.. Not a real beating on the plate surfaces and yet enough to stir and clean since the crystallization can't survive the heat so to speak.. Slow discharging and charging actually encourage crystal growth and should be avoided and that's why I also disconnect the AC line and run the inverter/battery combo feeding a well pump, chlorine pump and water softener every 2 to 3 weeks for recharge so that 8 amp load with 15+ amp surges when the pump kicks on can also exercise the batteries current flowing the other way.. I hope that in the next 5 years we get a new battery technology that is cheaper and more durable..

Re: sulfation?

Posted: Sat Feb 01, 2020 2:28 pm
by JRHill
Sparkey wrote:
Sat Feb 01, 2020 11:33 am
That's the thing isn't it, the difference between running absorb at 58.8v for extra hours as opposed to running 64v for 12 minutes as opposed to trickling at 54v which would not prevent crystal growth or stratification.. No matter what the lead plates will wear or decay loosing around 10% capacity even with perfect cycling because HCL electrolyte is an acid and Lead is a metal.. That is why I suggest 12 minutes of the EQ voltage once a week for standby batteries.. Not a real beating on the plate surfaces and yet enough to stir and clean since the crystallization can't survive the heat so to speak.. Slow discharging and charging actually encourage crystal growth and should be avoided and that's why I also disconnect the AC line and run the inverter/battery combo feeding a well pump, chlorine pump and water softener every 2 to 3 weeks for recharge so that 8 amp load with 15+ amp surges when the pump kicks on can also exercise the batteries current flowing the other way.. I hope that in the next 5 years we get a new battery technology that is cheaper and more durable..
I agree. Now I run a temp compensated absorb for 5 hours during the solar months. 58.8 is also about spot on for me. It makes the divergence between cells almost distinguishable from the pattern for the most part. And the divergence was consistent test after test. For example, if I ran a full EQ and looked at the non-EQ records, the same cells that were lagging day to day were behind, slightly, after the EQ. The EQ didn't make a straight line for specific gravity. It made it better but the pattern was there. But during four months of winter solar I don't have that luxury and I'm not going to run a genset for hours for the last few hours of absorb for a few amps. Even the Honda is wasting money doing that. .5kw finishing an absorb with a 7kw genset is nuts.

So a while back I initiated a new thing - I go to EQ (64) for a half hour or so and then shut it down every few weeks, just to hit the batteries - regardless of the SGs. But they are all over the place anyway cause they are older.

The wife is giving me the evil eye so I have to get to work....

Re: sulfation?

Posted: Sun Mar 22, 2020 12:06 pm
by JRHill
I'm going to post an update to the ongoing saga of the "1 in 8 RE16-B" failure which was actually 2 of them a week later. Much like nsoffgrid's post about the failed expensive genset I believe that I just had a run of misfortune on this bank. But frankly I'm tired of FLA batteries. There is SO MUCH waste in the charging cycle and draw down. Yeah, one can monitor them easily with a hydrometer but they really suck in efficiency compared to the new lithium batteries. Go there if interested.

Re: sulfation?

Posted: Sun Mar 22, 2020 12:34 pm
by raysun
JRHill wrote:
Sun Mar 22, 2020 12:06 pm
I'm going to post an update to the ongoing saga of the "1 in 8 RE16-B" failure which was actually 2 of them a week later. Much like nsoffgrid's post about the failed expensive genset I believe that I just had a run of misfortune on this bank. But frankly I'm tired of FLA batteries. There is SO MUCH waste in the charging cycle and draw down. Yeah, one can monitor them easily with a hydrometer but they really suck in efficiency compared to the new lithium batteries. Go there if interested.
Imagine that? A 200 year-old technology is lagging under the pace of modern power storage needs. 😉

Lead acid has had a pretty amazing track record though, one must admit.

The fast charging of lithium is definitely a good fit for an inverter power system. The fact that it is 'simply' moving ions instead of reversing a chemical reaction is a real leg up in the efficiency arena. That chemical reaction thing creates a real drag on maintenance.

I'd think lithium might be even better at standby applications than daily cycling, and it claims to be very good at daily cycling. As long as the battery is not held at 100% SOC, it's likely very happy to be idle until called upon. IMO, not so for lead acid.

The sorest points for lithium are cost - monetary and recycling. That, and the practical application of the technology is too new to verify the claims made in its marketing. How can 10 - 20 year service life be claimed when none have been in service for that long? We have to hope they're right, and that theory and lab simulations translate to the real world.

Re: sulfation?

Posted: Tue Mar 24, 2020 10:59 am
by JRHill
raysun wrote:
Sun Mar 22, 2020 12:34 pm
Imagine that? A 200 year-old technology is lagging under the pace of modern power storage needs. 😉
With Optics its pretty easy to get a handle on things (now [wink]). 1 1/2 months after installing the L16RE-B batteries in August 2015 the daily charge into them was 6.8kWh and usage was not reliable due to the M3 problems at the time but the average should've been <= 4kWk/day.

Now its an average of 9kWH in and 3.5KwH out. The previous bank of L16RE-A degraded in a similar fashion but, as is often said, the first bank will be sacrificed until one learns how to charge them. So every mfgr wants to tout things but at the best possible time - a few months in, properly conditioned, etc. But a few years down the line it just isn't the same. With the "B"s I thought I had it figured out. Absorb was adjusted, voltages too - and I greatly increased my collections of SGs and adjusted maintenance accordingly. Just to have one then a second battery fail due to one of the three cells in each going south. For conspiracy types, the first to fail was #1 in the string and #2 was the last. Both had the center cell fail. Yes, these are temp compensated and are on the outside placed 2x4. I blame the folks, any folks, on another continent. Somehow they hacked my batteries.

What I am really interested in is the efficiency of charge kWh in vs kKw hours out. Even when my FLA batteries were new the efficiency of production vs output sucked. But it is what it is. But with an aging strings of panels I want the best that I can get from them. The FLA or sealed stuff just doesn't approach the LI stuff.

Comments?

BTW, I see that OB doesn't have any LI storage in the line up. Because I love their stuff and support there must be a reason for that....

Re: sulfation?

Posted: Tue Mar 24, 2020 12:22 pm
by raysun
Yep, the failures are a Chinese plot to support the Lithium market. There, it had to be said before the deep state silences us all.

My 6' ball of tin foil continues to grow. You know, for use during the apocalypse.

There's no doubt what wins the race to charge - lithium is pretty much the Usain Bolt of the battery world. (Very fast, and very twitchy.) The simple(ish) charging profile is very attractive, even if one must flog traditional chargers into working it.

OB, along with most of us, is still aligned around lead. I expect that to change, but the supported base, and support, is a big ship to turn around.

I haven't searched exhaustively, but I haven't seen a Lithium only solution from anybody.

In the final analysis, I'll probably go the SimpliPhi route, even though their warranty is akin to trying to catch a coal scoop full of molten pennies. FWIW, I had to spend an additional $1k replacing two SLA battery blocks that failed 4 days after the end of the replacement warranty. I don't think any battery warranty is worth the electrons it is downloaded on.

Re: sulfation?

Posted: Tue Mar 24, 2020 12:41 pm
by JRHill
raysun wrote:
Tue Mar 24, 2020 12:22 pm
My 6' ball of tin foil continues to grow. You know, for use during the apocalypse.

There's no doubt what wins the race to charge - lithium
The dogs cover the apocalypse intrusion. If not, we have other coverage. But that's a different subject.

Really, I just need to get the best out of my stuff. Everyone else wants the same. Back to the previous subject, when it comes to $5k to $13k expenditures I'd rather be dealing with zombies. At least I can get immediate results. With batteries I have to wait 5 or 10 years.