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ICC
Member
# Posted: 6 Apr 2021 11:00
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From what you have told us the inverter would have been drawing current constantly. I don't believe there is any doubt about that. However, if the charge system was working the power used by the inverter is standby should have been easily replaced even if the weather was always cloudy.

Maybe the remote control did not actually turn off the inverter and something else was operating using more power than the sun could replace. That seems rather far-fetched, but is that a possibility?


So I believe that leaves you with a charge controller that failed in some way. The picture
indicates the PV was connected and had a 137.7 voltage. The CC read the battery voltage as 13.6 and thought the batteries state of charge was 100%. That indicates something wrong.

IF that CC meter is like most others it is simply giving a % reading based on the range of voltage expected from a lead-acid string of batteries. A reading of 100% would be expected IF the batteries were configured as a 12 volt system. With the system configured as a 24 volt system, a 13.6 volt reading should have been indicating 0%.

When you last saw the CC it had been working properly and supplying readings in the expected 24 to 28 volt range?

I wonder if it is possible that because the voltage fell so low, because of the output draw, if it is possible that the CC reconfigured itself to believe it was connected to a 12 volt battery?

But that still does not explain why the CC system quit charging the batteries. There had been no other strange behavior in the time the system was used prior to being left sitting?

I believe it would be not at all likely for the batteries to be the cause of the charging failure.

Chances would have been good that IF the inverter had been turned off properly, disconnected, and IF the CC then had failed and there were no actual loads, then the batteries would still have not frozen. I have left ATV batteries sit over 4 months in winter and not go dead enough to freeze, still able to crank the engine to start it. No loads and no charger.

So, my money is on a faulty CC or on something wrong with the way the system is put together. Or a power "leakage" of some king.

My next step would be to see if the voltage of the battery string can be raised high enough to make the CC believe it is connected to a 24 volt battery. Then reconnect the PV panels to the CC. See what it does and then see if the batteries are still servicable.

Is my belief that this was the first winter correct? Then you can compare former battery performance to what they do now.

Brettny
Member
# Posted: 6 Apr 2021 11:41
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Quoting: zorro
1 - batteries were not fully topped up and pretty low - covering the plates, but only just

2 - inverter has a certain draw on the batteries and would have been doing that for almost 4 full months (though if all else was working, the 1040W panels and CC should have compensated?)

3 - extreme cold would not have helped as the batteries began to draw down

4 - my panels would likely have been covered by anything from 12-18" of snow for maybe 4+ weeks during 2 pretty heavy snow periods and extreme cold


So that really only leaves either;

- the batteries were faulty and not holding a charge (not sure how likely that would be?)

or

- there is a fault in the CC that is not identifying when the batteries need to be charged

Also if the batteries where not fully charged, with snow on the pannels and the inverter drawing power..then you get a few cold nights your battery could freeze thus dropping voltage to the CC and shutting it off. At this point the harm is done and becids thawing them out and charging them I would stick them right back into service.

What part of NY are you in? I'm near norwich and had a spypoint working all winter and I saw roughly 24in on my picnic table for a good 2 months. I dont think your getting much solar through even 6in of snow. Your CC is also drawing power even when not charging.

ICC
Member
# Posted: 6 Apr 2021 13:22
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A question of sorts.... The 137.7 volts is quite close to the maximum voltage the CC will accept. It is supposed to shut down when voltage hits 150+. As it gets colder the voltage rises. Depending on how cold it gets it is possible the system shuts off on a very cold sunny day if the voltage rises too high. So, in theory you could have had sunny days and the panel power was not used.



As for snow, my experience has been that snow has never remained on the panels for more than a day once the sun shines.

zorro
Member
# Posted: 6 Apr 2021 13:33
Reply 


ICC -

I agree - the reading on the CC seems odd

Batteries were not 100% and all had failed with meter readings of around 0.9/1.1V

Likewise the 13.6V reading seems incorrect due to my 24V battery set up?

Interesting point in the CC reverting to thinking it was on a 12V system

All my batteries are at home and i am trying to charge them using just 2 chargers - so it is taking time - they are all getting to around 5.7V at the moment................I have a bigger charger arriving this afternoon and will try to get them boosted further

But they should all now at least be "visible" to the solar equipment (when they were reading 0.9, they could not even be identified) and should allow me to put them back into the system and see what happens

But i am also concerned about the CC and if that did actually go bad or something??...........though it is a lot cheaper than 8 new batteries!

I was last there early January and was not "aware" of any issues - however, what if the CC was playing up at that time and when i left for the 4 months, the batteries were not actually fully charged as i had thought - clearly that would be a major contributing factor



Brettny

I am up in Foresport - from web cams in the area, i know at times there was anything from 24-36+ inches of snow and that lasted for 4+ weeks due to the extreme temperatures as we get a lake effect as well

I would guess that the panels were totally covered (with 12+ inches of snow) for anything from 2-4 weeks with temperatures well below freezing for several weeks in a row

I know that batteries should cope with that - but for some reason, mine did not

I contacted the supplier of my equipment and he has no idea - like here, he feels that something clearly has failed and/or there was a draw over the winter while the panels were covered

He can get me another set of batteries at around $1400..............but think it is worthwhile trying to charge these as much as i can at home and then put them back into the system to see if they are recognized and charge - also good to use then if there is another issue

And i also wonder if i should go ahead and swap out the CC for around $250 and see what that does

I just dont want to spend $1400 without knowing what caused the issues as i would just be setting up for another potential failure!

zorro
Member
# Posted: 6 Apr 2021 13:39
Reply 


As for snow, my experience has been that snow has never remained on the panels for more than a day once the sun shines.


Interesting point but i have noticed that it seems to be different with my panels - here they are here

What seems to happen due to the amount of snow is that the snow does slide off, but literally falls in front of the panels and then if still snowing, begins to "back fill" onto the panels and creates a "wall" of snow which actually covers the panels

If you looks, you can see what i mean at the front of the panels in this picture as it starts to build up
Panels
Panels


gcrank1
Member
# Posted: 6 Apr 2021 14:52
Reply 


Pls, do not just buy more parts and hope you find a solution.
Are you charging the whole bat-bank together at home or one at a time on each charger?
If the whole bank, now that you have recovered a good bit of voltage, go for one at a time and check the bats not on chargers over, say, 6, 12 and 24hrs for how they fall off from the voltage they read when taken off charger (put a sticky note on each to keep track of date, time and volts). If you find one/some that wont hold a charge consider them dead and concentrate on the survivors.
Btw, you dont have to have all the bank hooked up to the cc to find out if/how it now works. And it may have hiccuped and went to it's default settings so be prepared to re-set. It is a 24v system, right? so 4 of your 6v bats can make a 24v bank to test things out.
See if you can recondition a good 4 set that hold a similar charge over time and load test about the same.

zorro
Member
# Posted: 6 Apr 2021 15:25
Reply 


That is good info - thanks

I am charging 1 at a time and have been spreading 2 charges across the 8

I get a new charger delivered this afternoon which is higher power and should allow me to hopefully charge them a little quicker

I wont be at the cabin for 2/3 weeks now so all i have here is the 8 batteries and a couple of small chargers

zorro
Member
# Posted: 6 Apr 2021 15:37
Reply 


The other issue is the 2 chargers i have been using are crazy slow - only 1amp chargers.................so taking forever

I have a 15amp charger arriving today so that should speed things up a little

They have all come from around 1v and now up to showing from 5.6 - 5.82V

Still no where near what they need to be, but i live in hope!!

gcrank1
Member
# Posted: 6 Apr 2021 16:23
Reply 


1 amp isnt really a charger, it is a maintainer. It can basically keep up with the self discharge of a fully charged battery with maybe a smidge more. No wonder you arent seeing much improvement! At least you are being gentle to the poor things
I expect a 6v x 15amp (max) will bring em up pretty quick now.
Then do the rest test and hopefully a load test. No sense in hauling bad batteries back up there thinking the illusory 'top charge' meant they were good.
Prove they are good, for sure and certain, first.

zorro
Member
# Posted: 6 Apr 2021 16:43
Reply 


Ha ha................yeah i know - it is painful

Actually the guy that sold me the equipment told me to try to use a really low powered charger to get them at least started, before moving onto something a bit stronger..............but paint dries faster!!

Just need amazon to deliver now!!!!

Thanks again and will keep the thread updated on progress!

gcrank1
Member
# Posted: 6 Apr 2021 16:59
Reply 


Well now ya got me wondering about the guy that sold you the stuff! And ime & fwiw 'normal electricians dont understand off-grid solar.
No worries, you will get good, solid info here and if you havent checked it out, visit the Diysolarforum.com to see what they offer.

zorro
Member
# Posted: 6 Apr 2021 17:26
Reply 


Yeah - some of the info the guy has given me has been kind of worrying .......and that is me saying that and I know nothing!

This forum is great and people really know their stuff

Thanks for e other link - will have a look

FishHog
Member
# Posted: 6 Apr 2021 17:38
Reply 


I wish you luck, but I had a new battery die in the summer due to a charging failure. One week of being dead in the summer months and there was no way it was coming back to a reliable battery.

The odds of yours recovering to anything usable after being that low and frozen in my mind are extremely low.

zorro
Member
# Posted: 6 Apr 2021 17:44
Reply 


Agreed...........but worth a shot at least!!

Brettny
Member
# Posted: 6 Apr 2021 20:12
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At 1a your able to bring them up to 5v+...I would say that's prety damn good and you many have skated by here. Usualy when batteries really freeze they do physical damage. It may not be the case this time.

I work as an electrician and I can tell you that most residential electricians are going to be no help. Just the fact that there could be a parasitic draw is totally out of there realm.

zorro
Member
# Posted: 6 Apr 2021 20:32
Reply 


So Amazon delivered!!

I now have the 15a charger on one of the batteries - right now it is at 5.5v

Be interesting to see what it is tomorrow morning - if no higher, then the battery is gone

Will let you know

gcrank1
Member
# Posted: 6 Apr 2021 21:27
Reply 


Be aware that the 15amps likely would be only at the beginning, as the battery reaches toward the top it cant take as much and the chargers typically cut back.
When I have several I rotate between them, the rest seems to stabilize them and they sometimes take a bit more on the next try. With 8 to do you shouldnt be bored.

zorro
Member
# Posted: 6 Apr 2021 21:53
Reply 


So any suggestions as to what to do to try bring them back to their level?

Put them all back in the solar array and see what happens or keep the 15amp charger running?

zorro
Member
# Posted: 6 Apr 2021 21:56
Reply 


And do you think it is worth taking them back to the cabin, reconnecting everything and see how they do in terms of charge?

Cause i really only have the option of 1 at a time at either 1amp or 15amp charging

gcrank1
Member
# Posted: 6 Apr 2021 22:08
Reply 


Charge on the 15 as well as you can, maybe put those appearing to take and hold a charge well on the trickle charger, and weed out any that dont seem healthy. If you can get 4 to make a solid 24v bank to hook up at the cabin it should be workable to test out the rest of the system and may well be adequate for conservative use.
I would want to do that to trial run rather than all the work to take and do all 8 not knowing how things will run. But you need to know you are taking the best 4.

ICC
Member
# Posted: 6 Apr 2021 22:13
Reply 


I would select 4 and charge those to full.
Record the voltages.
Let them sit unconnected to anything.for several days if possible.
Charge the others and record readings as well.
Recheck voltages on the first 4.
If they held voltage take them to the cabin.
Be sure the CC and inverter are completely disconnected from everything.
Assemble the 4 batteries in a single 24 volt string.
Connect the CC output to the batteries and activate. The CC should read the 24 volts and set that parameter automatically, or follow the manual.
Now connect the PV array and set charge parameters to suit the battery type.
See what happens. Does it charge?

Connect the inverter to the batteries and try a few different loads. Did you ever run something like a microwave? They draw a fair wattage. Just don't exceed the inverter capacity.

See how the batteries charge and discharge.
If all seems to be well and you need to leave be certain to at least use the inverter front panel switch to turn off or disconnect. I use HD breakers for that. Good ones have no problem being used like that.

zorro
Member
# Posted: 6 Apr 2021 22:24
Reply 


Sounds good guys - thank you

I will let you know how the charging goes over the next few days

Really appreciate all the help

Paul

Brettny
Member
# Posted: 7 Apr 2021 05:14
Reply 


Your inverter may have a time out shutdown setting also. My xantrax does, 24hrs no load and it turns off, a real turn off not standby.

zorro
Member
# Posted: 7 Apr 2021 08:39
Reply 


Good point Brettny - will need to check that

Quick update on the new 15a charger

Had it on 1 battery last night till this morning and battery only got to 6.06v or 50% charge

Charger did not identify a “bad battery” but did show “complete”

So am not sure it that is a bad sign or not as it only went to 50%

gcrank1
Member
# Posted: 7 Apr 2021 09:13
Reply 


You cant go by many 'good/bad' charger meters. Once the battery makes it to a surface charge (often a 'no-bean' but looks good) voltage the charger sees that as 'complete'. But you can see at 6.06v it aint fully charged.....
The no-cost test is to let sit for hours recording how it drops off, though with a 6.06 I might well just move on.
The real deal, no doubt test is the load test.

zorro
Member
# Posted: 7 Apr 2021 09:52
Reply 


Yep - after almost 3 days, none of them are getting above 50%

Looks as though they are shot which is no real surprise considering the froze and were showing 0.9v when I got there on Friday

gcrank1
Member
# Posted: 7 Apr 2021 10:47 - Edited by: gcrank1
Reply 


Id look for 4xGC2 replacements to make your basic 24v bank. Try to get close to the same mfg date and resting voltage 'in the store'. AH's would be about 220 for $450-$500ish.
If you cant get those, look for 2x12v grp 27 or 31 'Marine Deep Cycle (Not 'Starting') batteries to wire in series for 24v. AH's would be about 100-110 for $250ish or double the AH's and cost with 4 of those.
(you can make 24v with 2x12v, you cant with just 2x6v)
You can safely use 50% of those AH's in lead acid.
100AH's of cheap LFP are about $600 /80-90AH net usable), 200ah of cheaper LFP would be about $1200, but you could use 160-180ah of that. I wouldnt want to kill that bank working all the system out!
Fwiw, my basic system is now down to a 10yr old 129ah agm (so maybe 70% of new, 90ah?) and Im doing ok. And I have a decent Marine grp 27 in reserve at home on the smart charger.
Im not going all in for the big-buck position quite yet.

Brettny
Member
# Posted: 7 Apr 2021 10:56
Reply 


Smart chargers sold today will be no good to bring these back to life. You may need to buy an RV charger most are transformer based and can really push the amps/volts in. My iota brand 30a cost $100 and I can make it push 30a regardless of the batteries needs.

If you do need batteries I found a guy in highland NY that can get them. I'm getting two US battery gc2 220ah at the end of the week. I can get his number if you would like.
Screenshot_20210407.jpg
Screenshot_20210407.jpg


zorro
Member
# Posted: 7 Apr 2021 11:23
Reply 


Thanks again

Need to look at new batteries i think as these are not moving

Probably going to go with what everyone else up at the camp seems to have (other than Lithium guys), which are the T105's

Going to go for 8 if i can get them

Brettny - can you send me that guys number - Highland NY - is that over Poughkeepsie way or is there another Highland somewhere?

And in terms of core exchange, i assume i simply take along these dead batteries i have for that?

scott100
Member
# Posted: 7 Apr 2021 21:42
Reply 


Regarding batteries, I've been pretty happy with Duracell branded gc2 golf cart batts from Sam's club. They are made by East Penn who also makes Deka branded batteries. Less than $100 each.

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