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Nobadays
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# Posted: 29 May 2023 20:03
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Well, all winter I had a Victron battery saver on my shop batteries. Somewhere along the way in February it shut the system down for low voltage. When it came back on it would only let 19v through... still haven't one troubleshooting on that issue. Well I had my friends take the battery saver out of the circuit to get my system and camera back online. Worked great until it didn't.
A week ago at 8am I took a look at the cabin, everything was great. Got notifications of lightening in the area, tried to look again and the camera was offline. Stayed offline until we got here yesterday. Troubleshooting showed that the epever charge controller had for some reason decided my batteries were 12v, not 24v so let them run down to low voltage cutoff for a 12v system.... well the inverter quit at 17v so that's where it was at. The scc was flashing over voltage and not allowing charging. Today the scc was showing batteries at 29.3, full in absorption but when I shut it down and put a meter on the batteries, they were at 18v.
I'm pretty sure my batteries are toast. They were cheap, out-of-date 6v 200ah deep cycles I got for $60 ea. I got 4 years out of them and probably could have eked out another year or two until they got drained. It is what it is.... there goes another $1,200 for new AGM batteries! I leave that system on in the winter to run the camera so LiFePo4 won't work.
On a better note my Chin's LiFePo4 batteries in the cabin are great!
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travellerw
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# Posted: 29 May 2023 21:06
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Costco 6V GC6 are the best deal here. Properly cared for in a low use system they should last years (the batts in my trailer made 14 years before finally dying this year).
Sorry about the batts.. Sounds like something went awry. You have nothing to loose and could try to bring them back. High voltage and some Epsom salts could probably bring them back for another year.
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gcrank1
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# Posted: 29 May 2023 22:10 - Edited by: gcrank1
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My inherited system was big 12v agm's, ups bats x 4. As they failed things went flakey, getting the worst 2 out (the advantage of a 12v system) left me with 2 still working that I recharged (several sessions) on a new-generation smart charger with a 'reconditioning mode'. I got another year from the 2 then 6mo? from the last one (supplemented it with a pair of scrounged marine deep cycle's).
Just sayin it was worth my while to mess with saving what I could and having some elbow room to figure what way to go for replacements.
Btw, iirc over on the diysolarforum.com the Epever ssc's arent highly regarded? Things have changed a lot in the past couple years, it may be time to retire that unit if it cant recognize your bat-bank is 24v on a restart.
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Steve_S
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# Posted: 30 May 2023 07:56
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If the battery bank is below 19V the EPEver will register it as 12V, it may be 18V, I forget but that is not uncommon with most SCC's as they have to sense the battery voltage upon start-up to set themselves up.
For $1200 you can buy some serious battery !
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Nobadays
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# Posted: 30 May 2023 09:34
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As far as I can tell the batteries are shot. I have been planning replacing them anyway so not a big surprise. They drop off very rapidly as soon as the sun leaves the panels and that is with just one fairly constant load of 20-40 watts. They were cheap to begin with and got me by for several years, it's time.
Steve... I can see that. I had them on auto sensing so a good guess says they probably fell low enough overnight for the scc to decide they were 12v. The crazy thing is, I had taken the load off them after discovering what had happened to give them a chance to recover, they apparently fell low enough overnight with no load for the scc to switch to 12v again.
Yes, $1200 buys 4, tier 1 6v 225ah AGM batteries. If I was not leaving them on through the winter I would have went lifepo4.
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gcrank1
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# Posted: 30 May 2023 09:46
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For the low draw over-winter requirement how about using 2 cheaper 'marine' 12v in series for the 24v and having LFP for in season use?
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Nobadays
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# Posted: 30 May 2023 20:12
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That's a thought but I don't think "cheaper" ....I just bought a grp 27 battery for my pickup... $213.00. Thinking deep cycle marine would be comparable to the $300/ea I just paid for the 6v/235ah AGMs. Besides, 2 12v marine will not be able to run my Starlink for more than a couple days, the AGMs will do a week+. The batteries I just ordered will meet both summer and winter needs.
I'm definitely a proponent of LFP, but it has limitations in unattended winter operation.
I did just trick my epever scc into going into equalization tomorrow. If that works I might get the system back up for awhile.
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gcrank1
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# Posted: 30 May 2023 21:36
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I admit to being ch...frugal, and since our place is close to civilization we can replace failed stuff or retreat to home.
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travellerw
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# Posted: 31 May 2023 11:06
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Quoting: Nobadays Besides, 2 12v marine will not be able to run my Starlink for more than a couple days, the AGMs will do a week+. The batteries I just ordered will meet both summer and winter needs
Just out of curiosity.. What does the Starlink draw in watts?
I have been considering it, but I have good 5G service and the MIFI device I have only draws like 10W max. However the speed upgrade and unlimited data is tempting!
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Brettny
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# Posted: 31 May 2023 11:24
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Quoting: Steve_S If the battery bank is below 19V the EPEver will register it as 12V, it may be 18V, I forget but that is not uncommon with most SCC's as they have to sense the battery voltage upon start-up to set themselves up
I'm also thinking this is what happened.
I bet the system didnt get a charge for long enough for the voltage to drop then the CC changed it over to 12v.
My cheap Sam's club GC2 batteries are on year 2 I believe. I leave them hooked to the CC but with no load all year. When I'm there they run a fridge, charge devices and even tool batteries.
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gcrank1
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# Posted: 31 May 2023 14:16
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Lead acid bats of all types Like to be Kept Fully Charged.
When depleted any amount they want to be re-topped asap or they start sulfating. This is why automotive bats typically last so long, once the heavy starting draw down gets the engine running the alternator runs everything as well as recharges the bat quickly.
Solar not so much.....a balanced system is required; ie, the recharge from the use since the last solar charging hour should take place asap the next day. If the solar conditions are poor, or the array is undersized for the average load, the bats do not fully recharge and start to sulfate. Partially charged LA bats seem to be the cause of lots of less than optimum solar system performance.
Heavy discharge regularly, even if recharged reasonably quickly, cuts their life considerably. By heavy that is 50% or more; 25-30% discharge is Much better on them. Iirc Ive seen data that regular 50% discharge of LA bats cuts their life in half.
All that means to me that a LA bat bank needs to be well 'oversized' to keep the average daily discharge within max 30% and a fairly oversized array to recharge that by noon the next day. The scc needs to be sized to that array to utilize the array output to the max, that means a scc with a greater output than many want to pay for. But why have panels/array that you arent getting all the potential from?
After a couple good learning years it sure seems to me that in solar, for those that want/need a more like grid-tied cabin, it is 'go big or expect issues'. Often those issues come back to battery failures/premature replacement cycles. It is the cost of being your own power company. 
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Nobadays
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# Posted: 31 May 2023 14:57
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Yep I think a couple weeks ago when it hit low voltage and the inverter shut down was just an indication of a problem that had begun days before. It was really rainy/cloudy for about two weeks prior to the failure. Unfortunately my inverter has a lvco at ~17v, way too low but no way to adjust it that I'm aware of (Giandel 2000w). We probably got a bit of charging here and there but, the constant draw finally brought the voltage down to the threshold of the scc and it switched to 12v. When that happened, even though the inverter quit output I'm sure it was still drawing power. My batteries didn't have a chance after that.
Side note, meter registered 23v yesterday afternoon after a good day of sun... because the scc thought they were full they just trickled all day at 2amps, not much but enough to bring them up a bit. So I reset the date and time so the scc would go into equalization today. Went out this morning, 17v at the batteries with no draw at all, inverter disconnected.
The batteries have been dropping fairly quickly for over a year.... in part because when we came up last year the water level was so low all the plates were exposed. Equalization helped but didn't cure that oops. If they lose 6v overnight with no draw, they ain't coming back!
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gcrank1
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# Posted: 31 May 2023 16:06
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Oh yeah, mine were sad kinda like that toward the end. I lost one and pulled it out (4x12v so I could pull just one at a time) because it was drawing the others down. Its the 'bad apple' thing, a bad bat brings the bank down to the lowest common denominator.
After that I had to keep monitoring and would lose another. My clue was no real time on the bank until I got the bad one out.
Unless you like to putz with it and stay on the margin I say they are gone.
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redwolfguild
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# Posted: 31 May 2023 17:13
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Quoting: travellerw Just out of curiosity.. What does the Starlink draw in watts?
Mine draws 30-80 watts with my Kill-o-watt meter, depending on if the heater is on. If you turn off the "Snow Melt" option it averages 35 watts / hr.
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Brettny
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# Posted: 31 May 2023 19:53
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Quoting: Nobadays in part because when we came up last year the water level was so low all the plates were exposed. Equalization helped but didn't cure that oops
They where on borrowed time at that point. Have you thought about changing to a camera system like rep link or some other type of stand alone solar camera system. I use a single spypoint cam. Not the greatest but does capture people. I usualy use it to find out the snow depth so know when I can drive in or need to snowmobile in.
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gcrank1
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# Posted: 31 May 2023 21:12
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Plates exposed a little is better than a lot; did each cell take a lot of water to fill over the plates? Any exposed plates go bad fairly quickly and fast water use indicates too hot a charge. On a vehicle we would suspect the voltage regulator, the counterpart on solar is the scc.
If there is a scc control issue, internally or in settings, the new bats will also suffer. Being there and able to add water helps but maybe the scc needs to be toned down a bit?
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Nobadays
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# Posted: 2 Jun 2023 10:14
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Tried two days in a row to Equalize the batteries. Finally had sun long enough yesterday to get about 4 hrs of "boiling." Went out this morning to check and it might have done some good! First day since this saga began that lights weren't flashing and the batteries held the voltage overnight.
The last couple of days I'd have 23v in the evening and 17v in the morning. This morning 24.1v... still low but far better! We'll see how they do over the coming weeks. New batteries are on their way but I'm going to hold off installing them until I'm confident everything is working properly, especially the scc.
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Steve_S
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# Posted: 2 Jun 2023 11:17
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I'm going to suggest something that's a little tricky.
I used to use a Compaselect HydroVolt battery hydrometer, which let me "suck" the acid up into the tester to see what was going on. When I tested the cells in the old FLA, I would also use that to "mix" the acid up or stir it as such just Before I did Equalize. I found that this helped somewhat also as the acid does stratify inside.
Oddly no one mentioned this....
When you look at the acid in the battery, it should be clear - almost water-like. As an FLA ages out, the plates shed matter so of course the acid takes on a colour and while it is silvery/grey it is OK ~ BUT ~ if you start to see something looking like Rust (orange brown) you have serious issues at hand. The darker the acid get's the more worn the plates are and if it get's dark things can become dangerous and quickly.
Note that the sludge from degrading plates does sink to the bottom and stirring it up is OK because to shows you what's laying on the bottom. If you see Grey you are still safe but thick brown you are not.
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travellerw
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# Posted: 2 Jun 2023 11:40
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Quoting: Steve_S Note that the sludge from degrading plates does sink to the bottom and stirring it up is OK because to shows you what's laying on the bottom. If you see Grey you are still safe but thick brown you are not.
Almost all batteries have a space at the bottom for the sludge to settle and not touch the plates! Once enough material is shed, it can actually touch the plates and short them out. Usually shows up as a hot cell during charging (hot on sides and bottom).
In the marine world people would go to crazy measures to bring back batteries. It wasn't uncommon for them to empty the battery of acid, refill with a epsom salt solution, charge, the dump the epsom salts and put back the original acid filtered. (some internet sites say to just leave the epsom solution and toss the acid, but that is not how they were doing it down there). I have seen this process get 2 more years out of a bank.
I have personally revived a bank for 6 more months with just Epsom salts and high voltage charging. However, its temporary and mileage will vary. Could be 1 month, 4 months, 6 months or even a year, but they will fail again soon. Probably depends on how hard they are cycled.
Or... Just replace the whole bank and be done with it for a good number of years.
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Nobadays
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# Posted: 2 Jun 2023 15:03
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I haven't stuck my hydrometer in them yet. After I get them to float at least once or twice I'll take a gander. Good information regarding the color of the acid... I will pay attention to my samples.
I tried to Equalize them two days in a row, the first day the clouds rolled in just as they were reaching the higher voltage.... yesterday I got around 3.5 -4 hours of equalization. Surprised me when this morning they were still holding juice pretty well. I guess I didn't know how important equalizing fla batteries is.
Over the last year I've seen them degrade in their ability to hold a charge. I did them no favors when I came back last spring after being away 4 months to find all the plates exposed. So new batteries are needed but I'm going to milk these for all their worth!
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ICC
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# Posted: 2 Jun 2023 18:49
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Quoting: travellerw Or... Just replace the whole bank and be done with it for a good number of years.
My vote. I simply don't like making that-will-do "repairs except under emergency conditions
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Brettny
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# Posted: 2 Jun 2023 20:00
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Since this system is for a shop and not a primary power source I say try to revive them and even try different methods. You dont have anything to loose at this point.
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Nobadays
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# Posted: 2 Jun 2023 21:22
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I have already ordered the new batteries. That said because the SCC was acting funny I'm going to keep this set online until I'm pretty certain the SCC is operating correctly.... or find I need to replace it.
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