FLA guys, is my battery bank overcharging?

[sunshine_eggo]

my float is currently set to 55.2 I didn't lower it yet, and it has been there for well over an hour, I don't want to turn it off yet so as soon as I am done with the measurements which I'll wait another couple hours to do then I'll set it to 54 like the crown specs.

I would accept an elevated float voltage.

if the grid is on I use that to charge, smoother current than a generator no?

Yes. Sorry. Anything but solar.

All my wiring to the batteries is exactly the same length. I will try to notice if it bubbles at rest again and see if I can find a current.

here's why I was confused with the DOD, this a typo or editorial mistake then right? D being depth means lower is less higher is more, "below 50% DOD" would literally mean a lower number and that would be less DOD, a smaller load, "50% and above DOD" would be a higher number, more DOD and a bigger load.

View attachment 219936
and this is the water diagram, that is where I keep it, it has never been lower than an eight to quarter inch below this, some months it didn't need any at all

Yeah, that's worded a little back-asswards, and it includes that "generator" comment. It's correct if you replace DOD with SoC.

 

[Grateful Ed]

One of my inverters is charging at 3A and the other is not charging at all, 0A. I would assume it is very close to being totally full, seems insane there is no indicator, but there is not. the bank is sitting quietly at 55.2V

my load is pulling 1A or less from each 8 panel array

 

[sunshine_eggo]

One of my inverters is charging at 3A and the other is not charging at all, 0A. I would assume it is very close to being totally full, seems insane there is no indicator, but there is not. the bank is sitting quietly at 55.2V

my load is pulling 1A or less from each 8 panel array

If in float, it's only providing what the batteries need to maintain the voltage... 3A is still 3A * 55.2V = 166W.

 

[Grateful Ed]

tale of the tape they say…
not sad, I don't like the 1.260s, my hydrometer sits a little crooked, have to get another but time for an equalization I say, it certainly won't hurt anything I'll pop on the grid and run one for the 3 hours they mention. what say you?

 

[sunshine_eggo]

Yep

 

[Grateful Ed]

Follow up, After the first equalization charge, those 7 1.260 cells were reduced to 4, I let it sit for another three hours and ran another EQ, and this morning of the four one made it to 1.265, two showed improvement but were just not to the line so I called them 1.2625 and one remained at 1.260. I decided to go for it one more time, this really being a mild desulfation, they only warmed up to 90°, and lo and behold that last cell showed the same improvement I'll call 1.2625, nice to see the green above the surface. So now I have three cells just a shade below 1.265. Seeing as they call for it to be run every two weeks if need be it can't be that destructive so I will invoke it at that rate for a month or two and keep tabs on the results, it may clean it ever so much more. Thanks again and I will still be looking for a reason behind that insane night, unless I was getting a message from above to wake the F up on my battery maintenance responsibilities ha ha ha ha ha. Cheers…

 

[sunshine_eggo]

I know the bottom line is 1.265, but 1.260 really isn't a lot to worry about. Ideally, you want them all within a 0.03 range for uniform performance and cycle life.

Ensure you're charging to the Crown indicated absorption voltage and tail current and carry on with monthly EQ cycles.

 

[Grateful Ed]

Crown spec for absorption is 58.08V, float 54V, my defaults are 58.4 and 55.2, you had mentioned you thought the higher float was fine. The only thing I need to know now is if the EQ charge starts at the hour you enable it, there seems no other control than specifying the interval. I enabled it to force it at 4pm, I prefer it start at 10am, I bet that all I have to do is disable it and reenable tomorrow morning, I'm waiting on a tech support answer from phocos on the subject as there is nothing in the documentation. otherwise I'm feeling strangely confident matters are in hand, a recipe for disaster ha ha ha

 

[Grateful Ed]

Just found another chart that says to equalize at 60V, I'm running 59.2, I will crank that up, the other defaults look ok to me

 

[Bluedog225]

Maybe check your transfer switch?

 

[Grateful Ed]

Checked that but at the time the main breaker was off so the grid was totally shut off, there was no source of power nor had there been for probably 6 hours, yet the batteries were over 100° and gassing off, it was 3am, I think we were maybe having a weather inversion or whatever and it wasn't venting well, I had to air out the basement, never had to do that in the 11 months I had it running, I smell the gas when I open the box and its charging but when its closed it vents well, where was this gas coming from at 3am.

At this point I'm ready to take it as an omen to stay on top of things

 

[Hedges]

Separate the parallel strings. Let all 3 settle, check voltages.
Two may be dumping into one.

 

[Grateful Ed]

I might try that, everything looks pretty balanced right now, the few weaker cells were in all three strings and they aren't that weak so I don't think that had anything to do with it. I could turn the panels off and shut off the loads and let it sit and check for current between strings too. While I'm very curious to know, I'm knocking on wood that I never witness it again ha ha ha

 

[Hedges]

I think a weak cell is held up in voltage while charging occurs. That could be due to discharge from other strings.
If you isolate the strings, bad cell will settle lower and be more distinguishable.
If you have a clamp DC ammeter you should be able to see current in vs. out each string. If that occurring, it is bleeding off stored power.

Possibly, high discharge into something else is causing the heating. Didn't think it would cause bubbling.
With two strings isolated, they would be unaffected and remaining string would still experience it.

I think clamp ammeter is a necessity for PV and battery systems. I bought the Harbor Freight Ames 1000 because for just $1000 it measured DC up to 1000A and has resolution of 0.010A. The top brands, even for $400 I would only get 0.100A resolution, not great for comparing PV strings. Only a few very expensive models had 0.010A resolution.

The meter only sees what's happening now. Isolation lets you later measure/compare the cumulative effect over time.

Some problems self heal when ignored. I usually don't find that the case for facilities or vehicles.

 

[Bluedog225]

I had to check to see if you spend $1,000 on a harbor freight meter…..

 

[Grateful Ed]

Yup, I have the Ames 6000, very happy with it. I was going to mention that mine was considerably cheaper ha ha ha

 

[Hedges]

Does Harbor Freight offer a low cost alternate to this?

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After using one at work (rented, went back after a month) I bought myself the predecessor

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(for about 1/10th that price)
Mine only has 1 ppm full-scale resolution and is stable to about 1 ppm, but don't count on readings below about 4 ~ 10 counts of the least significant digit.

 

[Grateful Ed]

Does that come with a lab coat, horn rimmed glasses and a clipboard? Ha ha ha nothing like that just advanced caveman tools at horrible fright, but some are pretty good.