Author Topic: After upgrade Advice and Help on 1344 Watt PV / 24 volt System  (Read 1441 times)

cpttom

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After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« on: November 19, 2015, 03:59:02 PM »
I consider myself a  little  experienced and a definite noob, I could use some advice and some help: I recently upgraded my PV System at my remote cabin in the Southern Tier of NY (at 42 degrees latitude).   The original system configuration was 1344 Watt PV Array (2 in series x 3 parallel Sharp 224 Watt PV panels) Midnite Classic 150, Xantrex Prosine 1000 Watt, 2 x 2 6v 235AH Duracell Golf Cart EGC2 Batteries. a 3.2 KW generator was used with a 12V charger the few times we needed to charge the batteries when the solar couldn't.  This worked very well for the last two years, but the inverter was not really a 1K inverter and cut out on loads over 900 watts.  So, after recalculating our actually usage we settled on that we needed a 2KW inverter and more battery capacity. 

So we replaced the inverter with a Schneider Electric Conext SW 2524 Inverter, upgraded the batteries to 8 6v Duracell Golf Cart Water EGC2 Batteries (because this was in budget, it's what can be handled weight wise at the cabin, and we're still learning). The batteries were moved to the ventilated basement below the house which stays about 50 degrees F (10C) all the time. Also a 4.4 KW generator was added.  The inverter was done by the book, using SE's AC and DC switchgear panels as well as having an electrican wire up the inverter, charge controller, generator connections and the link to the battery pack. 

Issue #1:  This project was supposed to be done a year ago.  The batteries have been sitting during that time not charging (Yes, I realize this was a mistake).  The batteries at system startup were at 23.9 volts.

When the electrician was finished the generator was fired up to start the inverter, the inverter powered up, the charging light lit for 5 seconds and then stopped charging, the generator was lugging.  The AC power from the generator was being passed successfully as the lights were.  Since it was dark by this point,  I shut down the inverter,  and left the Classic up and the breakers opened  so the Classic could charge the batteries. I also disconnected one of the series of batteries to try to get at least one string fully charged.

Came back a week later and the Classic was charging the batteries, but at the ended of the day they only got to 24.4 volts.  I adjusted the charge Voltage settings accordingly: EQ 30Volts Absorb 29.1 Float: 26. Since the day was a bright sunny day I set off an EQ charge manually. The EQ ran for 2 hours. Then bulk, but it never got to float. During charging, the Classic showed the battery eventually make it above 25 volts, but, afterwards it it would show the voltage to be 24.8 and then under load it would drop to 24.4. Over time it would drop to 24.2.  We have been very miserly with power usage, mainly only using the power for lights.  Unplugged the small fridge

Issue #2 Noticed that the PV array is only generating between just under 600 watts at peak sun.  I don't think that has changed since the old system, so I am going to need to check the connections.  How is the best way to troubleshoot that?  last time I just used a volt meter to take readings at different points on the array  and at the DC disconnect.

I believe I should have enough power from the array to charge the batteries, if I get that properly diagnosed. However, I need some advice about the likely partial sulphating of the batteries.  I also think I need a need a bigger generator, or what would folks suggest. 

Sorry for the length of the post, wanted to be thorough. I appreciate any help in advance.  Please let me know what you think will help here.  Thanks!  --Cpt Tom
System: 1344 Watt PV Array (2x3 Sharp 224 Watt ND224UC9BX panels) | Midnite Classic 150 w/WBjr| Schneider Electric Conext SW 2524 Inverter, with SCP and Combox| 2x4 6v 235AH Duracell EGC2 Batteries @ 24V, 470 AH|  7 KW propane generator

zoneblue

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #1 on: November 19, 2015, 06:04:09 PM »
You have all sorts of issues there.

So we replaced the inverter with a Schneider Electric Conext SW 2524 Inverter, upgraded the batteries to 8 6v Duracell Golf Cart Water EGC2 Batteries...

Issue #1:  This project was supposed to be done a year ago.  The batteries have been sitting during that time not charging (Yes, I realize this was a mistake).  The batteries at system startup were at 23.9 volts.

FLA batterys left to sit for 12 months are likely very very unhappy campers.

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When the electrician was finished the generator was fired up to start the inverter, the inverter powered up, the charging light lit for 5 seconds and then stopped charging, the generator was lugging. 

Youll need to program the inverter to only draw what teh genset is capable of starting and running happily at. Given that its a 4kVA unit and the inverter is smaller, you would think it would be fine at the default. But try it at lower settings. Hopefully everything is wired up right, 120/240, grounding etc.

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Came back a week later and the Classic was charging the batteries, but at the ended of the day they only got to 24.4 volts.  I adjusted the charge Voltage settings accordingly: EQ 30Volts Absorb 29.1 Float: 26.

A full week of solar charging with no house loads and 24.4 is all it did? That is just wrong. What a sulphated battery looks like is the voltage goes up to setpoint real quick (looks charged), but sags prematurely on load. Get your self a DMM , and a clampmeter, and a hydrometer and see whats going on.

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Since the day was a bright sunny day I set off an EQ charge manually. The EQ ran for 2 hours. Then bulk, but it never got to float.

Rightly or wrongly a classic doesnt wait for float to try to do its EQ. So given that the bank isnt charging at all  EQ isnt going to help you there at all.

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During charging, the Classic showed the battery eventually make it above 25 volts,

Its doing something, then.

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but, afterwards it it would show the voltage to be 24.8 and then under load it would drop to 24.4. Over time it would drop to 24.2.  We have been very miserly with power usage,

Thats as may be, but your trying to draw power out of a bank that is clearly in a very low SOC. You need to find out why.  If you can resolve the charging issue, a decent absorb then EQ will determine if the bank is salvageable.

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Issue #2 Noticed that the PV array is only generating between just under 600 watts at peak sun.  I don't think that has changed since the old system, so I am going to need to check the connections.  How is the best way to troubleshoot that?  last time I just used a volt meter to take readings at different points on the array  and at the DC disconnect.

It will help to recall that PV can only source current, its up to the battery to accept it. It is possible your controlle r is set wrong, or even failed, but you need to rule out system issues as well.

Theres several ways to do this, but a simple way is to wait for a sunny stretch of weather. mesure the array voltage (at array and controller) and current, the battery voltage (at controller and battery) and current. Do the math, make sure things add up. Any significant difference in the 2 pairs of voltages point to a connection issue.

Im not sure what your current bank configuration is, 2P or 1P, but there are conceivable battery failure modes that might short out the bank, but those are much less likely than sulphation/high IR overall.

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I believe I should have enough power from the array to charge the batteries, if I get that properly diagnosed. However, I need some advice about the likely partial sulphating of the batteries.  I also think I need a need a bigger generator, or what would folks suggest. 

Partial you say. Umh, i think those are more than partial.

6x300W CSUN, ground mount, CL150Lite, 2V/400AhToyo AGM,  Outback VFX3024E, Steca Solarix PL1100
http://www.zoneblue.org/cms/page.php?view=off-grid-solar

cpttom

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #2 on: November 19, 2015, 10:16:22 PM »
Zoneblue thank you for responding, yeah this one got away from me (Mea Culpa, Mea Culpa, Mea Maximum Mea Culpa!).

You've given me some good places to start.  I am going to be able to go back out to the cabin in a couple of days
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A full week of solar charging with no house loads and 24.4 is all it did? That is just wrong. What a sulphated battery looks like is the voltage goes up to setpoint real quick (looks charged), but sags prematurely on load. Get your self a DMM , and a clampmeter, and a hydrometer and see whats going on.

Looking at the data on the batteries is interesting, the voltage goes up gradually, not quickly. though, after the charge starts it does drop down.  Anyway you are of course right that that batteries are likely sulphated. Question is how bad, and you've given me a better idea what diagnostic work needs to be done. Unfortunately fb

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FLA batterys left to sit for 12 months are likely very very unhappy campers.

Shattering my illusions why don't you  ;).  Hopefully not completely toast, I am just hoping at this point I can salvage them.

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Youll need to program the inverter to only draw what teh genset is capable of starting and running happily at. Given that its a 4kVA unit and the inverter is smaller, you would think it would be fine at the default. But try it at lower settings. Hopefully everything is wired up right, 120/240, grounding etc.
The electrician who did the work comes highly recommended and has done other work for me, plus I've gone over his work comparing it to the installation manual. Everything looks as it should.  I think it is more likely that I fouled up the inverter configuration. I will check both again.


I think the controller is doing something, ie charging or attempting to charge, but could the battery just be so sulphated that it isn't charging?  Is there a way to bring them back if they are??

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Thats as may be, but your trying to draw power out of a bank that is clearly in a very low SOC. You need to find out why.  If you can resolve the charging issue, a decent absorb then EQ will determine if the bank is salvageable.


hmm.  looks like I need to go over things more thoroughly with the DMM, clampmeter, Hydrometer.

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It will help to recall that PV can only source current, its up to the battery to accept it. It is possible your controlle r is set wrong, or even failed, but you need to rule out system issues as well.

Theres several ways to do this, but a simple way is to wait for a sunny stretch of weather. mesure the array voltage (at array and controller) and current, the battery voltage (at controller and battery) and current. Do the math, make sure things add up. Any significant difference in the 2 pairs of voltages point to a connection issue.

Sunny weather, that is a rare commodity right now, not to mention we are heading into winter here in New York...not sure if we'll get a long Sunny stretch.  Going to have to watch the weather reports.

I believe it is more likely I mis-configured something.  I will go back through and check things, and make the comparisons as you suggest

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Im not sure what your current bank configuration is, 2P or 1P, but there are conceivable battery failure modes that might short out the bank, but those are much less likely than sulphation/high IR overall.

Current battery configuration is 1p, but I was going to put it back to 2p or would that be the wrong thing to do?   The sulphation is the likely culprit.

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Partial you say. Umh, i think those are more than partial.

As you said, unhappy campers.  I think that is the case. 


I will check things over the course of the next few days...have to go back out to the cabin to do this...I'll report back what I find.  I do appreciate the wise and direct consult..  All the best!
System: 1344 Watt PV Array (2x3 Sharp 224 Watt ND224UC9BX panels) | Midnite Classic 150 w/WBjr| Schneider Electric Conext SW 2524 Inverter, with SCP and Combox| 2x4 6v 235AH Duracell EGC2 Batteries @ 24V, 470 AH|  7 KW propane generator

Vic

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #3 on: November 19, 2015, 11:00:27 PM »
Hi cpttom,  welcome to the Forum,

Just a couple of comments;

Would NOT expect much,  if any PV production increase when going from your original 1344 W STC of PV on a 12 V system,  to the same PV power on a 24 V system,  with a Classic 150 CC.

Check  the Absorption Time setting in the Charge menu of the Classic.  With severely depleted batteries,  you would want a L O N G   Absorb.   Assume that you are not using the WbJr with the Classic.   When you are around the cabin,  set the Absorb time to 10,  or so hours.

Since your batteries are essentially dead,  increase your Absorb voltage to 60,  or so volts ,  to try to get as much charging from PV crammed into each day.

You mentioned that you are seeing about 600 W output from the Classic in bright sun ..  assume that this was when the CC was in Bulk,  or perhaps EQ MPPT.  In theory,  on a bright,  sunny day,  with the sun directly overhead,  that PV array might be expected to produce about 1075 Watts output to the batteries  (in an MPPT Mode).   But the elevation angle of the PVs,  thin clouds,  or even slight shading can significantly reduce this output.

If your new,  uncharged for 12 month batteries were in your cellar,  they may not have been destroyed,  due to the cool environment.

BUT,  you really must get these batts fully charged quite soon.

Also,  how is it that you are setting the Charger parameters for the SW inverter?   Believe that one needs the SCP,  or perhaps the Com Box to do custom settings.  The customary Default charger settings are usually horribly LOW in voltage for Flooded batteries.

Make sure that you are using Remote Temperature Sensors (RTS or BTS)  on EACH charge source.

More later,   Thanks,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

cpttom

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #4 on: November 20, 2015, 07:55:19 AM »
Hi cpttom,  welcome to the Forum,

Just a couple of comments;

Would NOT expect much,  if any PV production increase when going from your original 1344 W STC of PV on a 12 V system,  to the same PV power on a 24 V system,  with a Classic 150 CC.


Vic, Thanks for the welcome, been lurking for a bit, decided to come out of the shadows so to speak. ;)

I was realistic, I wasn't expecting an increase in PV production, but, I was questioning whether I was getting what I should from the array.  I was expecting to get more from the batteries (which I'm not because of the mess with the batteries) and the inverter to meet loads above 1K.

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Check  the Absorption Time setting in the Charge menu of the Classic.  With severely depleted batteries,  you would want a L O N G   Absorb.   Assume that you are not using the WbJr with the Classic.   When you are around the cabin,  set the Absorb time to 10,  or so hours.

right now  set for 2 hours.  I will increase it.

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Since your batteries are essentially dead,  increase your Absorb voltage to 60,  or so volts ,  to try to get as much charging from PV crammed into each day.

I have the Absorb set to 30 volts right now.  The max voltage of the array is 58 volts.  I could rewire to 3 in series in two parallel strings to get close to 90, then I could do that. What is the downside to charging at that voltage...any risks there? (I don't want to burn the cabin down ;) )

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You mentioned that you are seeing about 600 W output from the Classic in bright sun ..  assume that this was when the CC was in Bulk,  or perhaps EQ MPPT.  In theory,  on a bright,  sunny day,  with the sun directly overhead,  that PV array might be expected to produce about 1075 Watts output to the batteries  (in an MPPT Mode).   But the elevation angle of the PVs,  thin clouds,  or even slight shading can significantly reduce this output.

I will check the angle of the PVs.  At peak production there is no shading. so I will start with the angle.

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If your new,  uncharged for 12 month batteries were in your cellar,  they may not have been destroyed,  due to the cool environment.

BUT,  you really must get these batts fully charged quite soon.

Yes, they were stored in the basement, which is generally around 40-50 degrees F.   Never freezing even when we had  -30s last winter.


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Also,  how is it that you are setting the Charger parameters for the SW inverter?   Believe that one needs the SCP,  or perhaps the Com Box to do custom settings.  The customary Default charger settings are usually horribly LOW in voltage for Flooded batteries.

Make sure that you are using Remote Temperature Sensors (RTS or BTS)  on EACH charge source.

More later,   Thanks,   Vic

Ah the inverter, yeah that.  Had the wrong SCP, a new one is on the way. Apparently Schneider Electric has segregated it's product line so that you cannot use a Xanbus SCP or Combox from other lines (Older Xantrex and the current Freedom line) you have to use the SCP for only the Conext SW / XW line.  New one arrives today so I can make changes to the inverter this week end.  Any suggestions what levels  to set the charger at? The default is 25 volts which I know is wrong.

The Classic and the Inverter have Battery temp sensors,  so that at least is right.

Thanks for the help Vic, I appreciate it.  I'll get back to you and Zoneblue when I get out to the cabin and back. 

System: 1344 Watt PV Array (2x3 Sharp 224 Watt ND224UC9BX panels) | Midnite Classic 150 w/WBjr| Schneider Electric Conext SW 2524 Inverter, with SCP and Combox| 2x4 6v 235AH Duracell EGC2 Batteries @ 24V, 470 AH|  7 KW propane generator

Vic

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #5 on: November 20, 2015, 02:46:04 PM »
Thanks for the detailed reply,  cpttom,

Running your PVs in strings of two of these 60-cell modules is perfect  --  voltage into the Classis neither too high,  nor too low.   If you were to rewire the PVs as strings of three,  the CC would be a bit less efficient,  so you would lose a bit of ground on PV production.   IF you were running a 48 V system,  then,  definitely,  strings of two PVs  would have insufficient voltage to allow full charging or EQing of the battery.   BUT  your strings of two PVs  is the best on a 24 V system.

Too bad about the differing SCP/ComBox,  etc on the SW verses XW inverters  --  Schneider wisdom,  I guess.

Good Luck,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

zoneblue

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #6 on: November 20, 2015, 08:41:09 PM »
Ok sounds like a plan. But is it reaching absorb at all?

40-50F storage, does increase there chances a little. (although you wouldnt have wanted to see a flat battery go below 32). And factoring your present weather helps understand the solar production, as vic said.

What you shoud expect:

1344 Watt 60 cells, 2S3P (assumed mounted south, at lat 40, tilt 20 deg)
430Ah, 24V FLA, 4S2P.
Pvwatts gives 2.7 sun hours for november.
So 1344W * 0.77 pv/cc derating  is 1030W. (allowing for panel heat, wire resistance, controller effciency etc)
Nominal peak charge rate is 1030W/24V = 43A or  0.1C (good).

But in november becasue the sun is 11.6 degrees lower on the horizon (compared to the equinox), not only is angle of incidence onto the array greater, but the air mass is thicker as well, so you wont get the full 1030W peak. Based on some quick back of envelope math, the greater angle of incidence will reduce that by 10% and the thicker air another 4%, and[1][2]. Thus 880W sunny day noon peak would not be unreasonable.

Now if we take the pvwatts figure of 2.7 sun hours  that gives you 3000Wh/day on an "average" november day.
Which when put into a 10kW bank, ought to raise the SOC by 30% per day.

Therefore after two sunny days and no loads and the bank isnt reaching the absorb setpoint something is wrong. As said above a sulphated battery has less available sulpher, less capacity and a higher internal resistance. All of that typically leads to a battery that comes up to the absorb voltage quicker, not slower.

Im with vic, temporarily set the absorb setpoint to something high like 35V, and the absorb time, to something high like 12hrs. You need the extra volts to overcome the extra resistance.  Again as vic said the array at 60cell 3S is fine, theres oodles of voltage headroom there. Let it run for a few days like this and see what happens to the SG.

[1] http://www.pveducation.org/pvcdrom/properties-of-sunlight/air-mass
[2] http://www.pveducation.org/pvcdrom/properties-of-sunlight/solar-radiation-on-tilted-surface
6x300W CSUN, ground mount, CL150Lite, 2V/400AhToyo AGM,  Outback VFX3024E, Steca Solarix PL1100
http://www.zoneblue.org/cms/page.php?view=off-grid-solar

cpttom

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #7 on: November 21, 2015, 08:16:22 PM »
I was out at the cabin yesterday, of course before the SCP arrived (that didn't arrive until this evening).  It was a bright sunny day here, so the wattage was close to 700watts at peak.  I suspect that the angle is not quite right, and that there is some faint shading going on earlier than I expected (Winter's approach?)  During daylight, I checked the voltage at the PV array with my multimeter. it registered in the 53-59 volt range and, did the same at the charge controller, it registered the same voltages.  I don't have a clampmeter yet so I can go too far into much else.  I boosted the absorb voltage on the Classic to 35 volts, the time to 12 hours. 

Additionally, when it was night, I used a hydrometer to check the SOC with everything off and the system was resting a couple of hours.  The 4 batteries in the first series, each had 1 or 2 cells in the 1.20-1.22 range and the others were 1.1-1.2.  This is the one that had been charged a week, so, I'm guessing it it is coming back sloooowly.  The 4 batteries in the second series, the one not hooked up, had 1 or 2 cells in the 1.1-1.2 or 1.2-1.22 range, the other cells were below 1.1. 

I have connected the second series and moved the positive battery lead to the second series connected to the last battery to be opposite the negative lead on the first battery of the first series.  The liquid in all the cells was clear and without particulates.  Maybe the batteries aren't completely toast?

I have left the inverter powered down, and I will see what progress happens between now and when I go back in a few days. At that time I will use the SCP to fully configure the Inverter, so maybe I can use the generator to help charge the batteries. 

All the best.  --CPT Tom
System: 1344 Watt PV Array (2x3 Sharp 224 Watt ND224UC9BX panels) | Midnite Classic 150 w/WBjr| Schneider Electric Conext SW 2524 Inverter, with SCP and Combox| 2x4 6v 235AH Duracell EGC2 Batteries @ 24V, 470 AH|  7 KW propane generator

Vic

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #8 on: November 21, 2015, 10:31:27 PM »
Hi Tom,

Thanks for the update.   Well,  things do not look that good for your batteries.  1.1 = DEAD  --  the electrolyte is essentially water.

Running batteries into very deep discharges,  and not recharging them immediately is very,  very hard on them.    If one,  or more cells become completely discharged,  they  can be charged in reverse,  with any load.   Charging cells in reverse is really permanent DEATH for them.   But,  since your batteries may have been discharged  only as a result of self-discharge,  perhaps none of the cells were charged with reverse polarity.

But in any case,  given the SG readings,  am much less sanguine on the state of your batteries.

It is good that you have the SCP for the SW,  now.  Some serious generator time seems in order,  now.

It is uncommon to find particles in the electrolyte of FLA batteries.   One can see some evidence of very fine,  grey particles on the device called a Moss Guard,  that is placed on top of the plate separators on some batteries.   This grey dusting on this perforated plastic guard is really just very fine positive plate (primarily) material from customary plate erosion.

The Clamp DC Ammeter will help you monitor current balance between your two battery strings.  At this point you might try charging both strings at the same time,  from the generator while you are at the site.

You might want to think about trying to select the highest SG batteries,  as a candidate for the only surviving string of the two ...  just think about it  Trying to charge both strings at once,   from the genset now  for a day or so,  to see how the lowest batteries do.   The lowest cells will be that last to charge,  as their terminal voltage is lower than are those with higher SG readings,  unless they are Hard-Sulfated.  Hard sulfate acts like an electrical insulator,  and hides much of the plates from the electrolyte,  and reduces the amount of charge current that will flow through that cell,  and therefore will limit the charge current for the entire string.   This reduced string charge current will limit the amount of charge that the higher SG batteries will receive.

So,  trying to segregate low SG batteries into one string,  and higher SG batteries into a second string might help,  realizing that there might be high and low SG cells in the same battery ...  it is never simple.

You are in a difficult situation (yea,  you do know this).  It is difficult to say just how one should proceed,  as this all depends upon the conditions at your site.

I have tried to resurrect some L-16,  6 volt batteries that a neighbor had abused  --  two strings,  with one string better than the other.  It took a lot of time,  and in the end,  while remedial efforts did improve the Capacity of the problem batteries,   a bit,  they still had very little Capacity.   These batteries were recycled,  and that site reverted to a single string of good batteries.

Good Luck!    Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

zoneblue

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #9 on: November 21, 2015, 10:32:17 PM »
Those SGs sure dont look too great. If you dont see any progess, you might take the half with the highest SG and put them into a single string and concentrate on those.

Edit... oh yeah just as vic just also posted.
6x300W CSUN, ground mount, CL150Lite, 2V/400AhToyo AGM,  Outback VFX3024E, Steca Solarix PL1100
http://www.zoneblue.org/cms/page.php?view=off-grid-solar

cpttom

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #10 on: November 22, 2015, 12:06:29 PM »
I do appreciate both of you, zoneblue and Vic, advice and council here.  You guys are the best. The battery situation is going to be a cross to bear for now, and I am going to have to take a slow approach here, as the weather is not stable this time of the year in NY.  We are in the rainy and then snowy season. It is unlikely we are going to experience a week of sunny weather, rather one or two days of sunny with partly cloudy and cloudy interspersed. I am going to see how things progress.  Gotta get the generator and the inverter working it's a priority. They're on life support, it isn't pretty.

A little good news.  Over the past week the batteries have gone from not holding much of a charge (less than 5 percent) to charging to 20 percent.  This is not big, but it may mean progress. I may be whistling past the grave yard, but it is a flicker of life.

From the wilds of NY Best regards.  --CPT Tom
System: 1344 Watt PV Array (2x3 Sharp 224 Watt ND224UC9BX panels) | Midnite Classic 150 w/WBjr| Schneider Electric Conext SW 2524 Inverter, with SCP and Combox| 2x4 6v 235AH Duracell EGC2 Batteries @ 24V, 470 AH|  7 KW propane generator

Vic

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #11 on: November 26, 2015, 03:10:29 PM »
Hi Tom,

Yep,  you have little to lose,  other than some of your time,  in trying to get these batteries back into shape,  unless you really need battery at the cabin this Winter.

Perhaps,  you could transport the batteries back to your main home,  although,  you may not have a good charge source,  there.  But,  having Grid power (assuming that you would)  is a huge help in trying to resurrect batteries.

Most Automotive battery chargers are unable to do an EQ.   And alternatives to those inexpensive chargers could be expensive.

Good Luck,  and please let us know how you are progressing.  Thanks  Happy T-G,  Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

cpttom

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #12 on: January 29, 2016, 11:01:29 PM »
Hi Vic and zoneblue,

I thought I should bring you up-to-date of where things are at with my batteries.  We shut the cabin down for the last couple of weeks of December and most of January, and left the Classic charging the battery at the levels you guys very helpfully suggested. 

Yesterday I came back to the cabin to do some work over an extended weekend. The batteries were showing fully charged on my arrival, and after dark  the batteries voltage was 25.2 volts, and were at 25.0 volts by this morning. 

Today the batteries charged again almost to full, though we ran some heavy loads late in the day and the batteries were at 25.0 and are holding at 24.8 for  the last 4 hours.  Running quick heavy loads (like a bathroom fan during a shower) shows a .1 volt drop during load and a recovery back to 24.8.  Also today I checked over ag all connections again on the array, turned out there was at least one loose MC4 connection. Array Charged at 300 watts (Noon) under cloudy skies, and on average about 150 watts. It appears there is afternoon shading at this time of year as well.  This was much better (it was charging at 50 watts) what it was doing just before I checked the connections.  I am hopeful, if we get a sunny day that production will be even better.  But I don't expect a sunny day for awhile to confirm things.

A new dual fuel (petrol / LPG) generator (6500w / 7500w) install is on the agenda for this weekend.  I also purchased a Wiz-bang and am planning to install that as well this ) install is on the agenda for this weekend.  I also purchased a Wiz-bang and am planning to install that as well this weekend. 

I am wondering if I should lower the EQ & Asorb Charge voltage and time  back to something more normal. Any advice on what I should set them at would be appreciated.

Well that's where things are at.  Thanks again for the help and advice.  --Cpt Tom
System: 1344 Watt PV Array (2x3 Sharp 224 Watt ND224UC9BX panels) | Midnite Classic 150 w/WBjr| Schneider Electric Conext SW 2524 Inverter, with SCP and Combox| 2x4 6v 235AH Duracell EGC2 Batteries @ 24V, 470 AH|  7 KW propane generator

mike90045

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #13 on: January 30, 2016, 12:19:10 AM »
What was the water level after the long absence ?      Water usage is a fair indicator of if you are charging enough.

   If you had to add none or a little water, you are good as is.

  If you had to add a lot, I would dial back the charging some.
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Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

Vic

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Re: After upgrade Advice and Help on 1344 Watt PV / 24 volt System
« Reply #14 on: January 30, 2016, 12:31:12 AM »
Hi Tom,

Thanks for the update ...

SG readings are more useful than are voltage readings,  without a reference to the battery temperature,   when trying to determine approximate State Of Charge ...

BUT,  things look better ...

Be certain to take and record SG readings on each cell of each battery.   SG readings need temperature compensation,  but this is fairly small compared to the temperature effect on  voltage,  especially without knowing the battery temperature when the voltage reading was taken.

More Later,   Vic
« Last Edit: January 30, 2016, 12:44:58 AM by Vic »
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!