Stumped on SG values not increasing

elesaver · June 2016

My forklift batteries have been performing well. (This is a 24V system, 938 aH, Classic 200, 8 ea 300 W panels.) I was "sailing along" quite nicely. I had checked the SG in late April. All cells were 1.285 at that time. I had been told that I didn't need to constantly check the SG, just the water, etc. Since then, I have monitored the aH level at the classic but not the battery SG. I had noticed that the low battery voltage light would be on after the night's use several nights ago but expected it to regain. We had had some rainy and cloudy days. Yesterday, the SG measured 1.21! Today, in order to get those levels up again, I set the EA to 0, the Absorb voltage to 30.5 and the Absorb time to 4 hours. I had had the Absorb voltage set at 32.5 for a while but was trying to lower that since others seemed to think that was too high. Maybe not after all. Anyway, today we've had a pretty nice day although the brightest of the sun was in and out. There was good light all day,however. The voltage did not reach the 30.5 to get into absorb mode nor did the battery voltage increase much. I measured the SG and it was still 1.21. I do not hear any of the bubbling sounds at any point during the day.

The load is approximately 2.5K for 24 hours. That was determined by a kill-a-watt meter early on. I had calculated that my panels would be enough with nominal voltage at 36.73 and amps at 8.1. There are 4 strings of 2 into a combiner box then into a mini-dc disconnect, then to the classic. I have an outback VFX3524 inverter. I also have a "homemade" temperature sensor but verified that temp today with a mercury thermometer into the electrolyte for a couple of hours. FETS are high 56.7 at one time today. At least, that seems high to me.

Would someone mind "chiming" in on this as I need to get this SG up where it belongs. Manufacturer says 1.285. Thanks for the suggestions. I hope I've given enough of the settings for the classic. Last week, I had had the whole system shut down while I changed some wiring. When I powered everything back up, I was checking to see that the WBJr was working and it is. BUT, since that shut down which was for a few hours on one day, things don't seem to be back to snuff. I do not recall changing any of the settings on the classic but maybe I did and didn't realize it. The wiring itself was not anything changed but just cleaned up as far as the panel goes so it's nothing to do with that process. Hopefully, this is enough info.

Vic · June 2016

Hi elesaver,

You should not need to check SGs more than once per week, unless you suspect an issue. When one is changing charge parameters, I would check SGs every day, and make small changes to charge parameters as one feels that they are close to optimum.

It is a good idea to have at least several Pilot Cells -- usually the cells with the lowest SGs -- as a quick check on nominal SGs of the bank.

What had been the Absorb voltage and Time, and the EA setting previously?
How often do you EQ the batteries, and a what voltage, IMO, you should set the Classic to Temp Comp the EQ voltage.
What was the highest voltage that the battery got to today?
Are you using the Hydrovolt Hydrometer for these SG measurements?
What is the battery temperature?

IIRC, believe that member, Photowhit EQs his battery once per week +/--. Forklift batteries are among the tallest batteries around, so they can be prone to electrolyte Stratification, and tall batteries can need high Vabs and Veq to help mix electrolyte. With a full-charge SG of 1.285, you would need a bit higher voltage settings for every charge parameter. The Gassing voltage will be a bit higher, also on high-ish SG batteries, compared to batteries with lower fill SG electrolyte.

Many forklift batteries have a fairly small electrolyte Reserve (space above for electrolyte above the plates). Would suggest checking water levels every few weeks, especially in Summer, or when the batteries are being cycled fairly deeply.

Would suggest adding Distilled Water only during Abosrb, or, perhaps during EQ, to allow good mixing. You might even want to do either a short EQ , after Absorb has ended when water has been added, or increase the Absorb voltage after water has been added.

YES, your strings of two PVs with STC Vmp of about 36+ volts should be fine on the Classic 200.

It is OK to use your genset to charge the batteries, as well, as it appears that today's charge from Solar has made NO measureable progress. Recall that this system is really a Grid Backup, so you may be able to charge from the Grid.

Believe that you have seen the Surrette Article on Measuring SGs:
http://support.rollsbattery.com/support/solutions/articles/4347-measuring-specific-gravity

AND, be absolutely certain to rinse that Hydro well, with Distilled Water three or four times after a measuring session.

Later, Vic

vtmaps · June 2016

elesaver said:

Last week, I had had the whole system shut down while I changed some wiring. When I powered everything back up, I was checking to see that the WBJr was working and it is. BUT, since that shut down which was for a few hours on one day, things don't seem to be back to snuff.

I believe that the WBJr needs to be reset when the batteries are at 100% SOC.

--vtMaps

Photowhit · July 2016

First question, are your batteries 6-85-15 purchased from GB battery?

Did you read this;

Please note that the published 20 hour/Ah rating from GB Industrial is not correct! We have had a discussion about that here somewhere (I have one!) The multiplier should be closer to 1.35 x the 6 hour rate. Their published rates. I will try to hunt down the thread for you when I get a chance.
http://gbindustrialbattery.com/Forklift_Battery_Sizes_and_Specifications_Zone15.html
Ask them for or look at your sheet for a break down of the battery. You should get something like 6-100-13 which is 6 cells, 100 amps per positive plate(6hr rate), and 13 plates (of which 6 are positive) for 600 Ah at 6hr rate or @810 20hr rate.

mike95490 · July 2016

When in bulk, some gassing sounds should be heard, and for sure in absorb. To not hear gassing, means they are not charging. Do you have a clip on DC ampmeter to verify amps are going to the batteries and the Load is not sucking them all up?
Running the genset for a couple hours to bulk them is MANDATORY to prevent death of the batteries. Start the genset early in the AM. so it can BULK the cells, and then the solar can manage the absorb stage. But you must charge them and reduce loads ASAP.

If you use the Local App from midnight, it's easy to control the Classic and start an extra absorb cycle.

Photowhit · July 2016

Second question, You "....determined by a kill-a-watt meter..." Did you add an efficiency factor for your Inverter and transformer?

Third question, Did you ever change your settings from "Bulk is set at 27.8, float at 26.5, EQ at 31.2" If Bulk is set to be limited at 27.8 That's pretty low. Check with the battery manufacturer, Limit on bulk/ transitioning to absorb should be around 29 volts (unadjusted) for a 24 volt flooded lead acid battery.

Statement, You have a Honda generator and a inverter charger, I would change the bulk/absorb setting then fully charge your battery with the genny and inverter/charger one morning. then check SG and let the solar array equalize in the afternoon.

Also you state one SG, each cell has it's own electrolyte, check them all, if they are even great, if some are lower worry! Run equalizing and check SG each hour, continue until the Sg doesn't rise

Vic · July 2016

mike95490 said:

When in bulk, some gassing sounds should be heard, and for sure in absorb. To not hear gassing, means they are not charging. Do you have a clip on DC ampmeter to verify amps are going to the batteries and the Load is not sucking them all up?
Running the genset for a couple hours to bulk them is MANDATORY to prevent death of the batteries. Start the genset early in the AM. so it can BULK the cells, and then the solar can manage the absorb stage. But you must charge them and reduce loads ASAP.

If you use the Local App from midnight, it's easy to control the Classic and start an extra absorb cycle.

Was speaking of THE Gassing voltage, which is generally a bit below the minimum specified Absorb voltage from the manufacturer of the specific battery. Some gurgling sounds can be heard on most Flooded batteries, even at night, long after PVs have stopped any charging. This is probably due to trapped gas bubbles stuck on the plates or on the plate envelopes, occasionally breaking loose ... at least on the FLAs here.

I had thought that elesaver had grid power, after reflecting for a bit.

From the MNGP, one can easily Force Bulk ... Tweaks >More > Force Bulk, IIRC.

FWIW, Vic

elesaver · July 2016

Thanks for the suggestions listed above. Several additions to answer some of the questions: yes, I have checked all the cells for SG; the readings are about the same for all by using the hydrometer. This is an off-grid system but I do have access to grid power when needed. I had seen the info about the GB battery and discrepancy...but had forgotten. Overnight, the usage has been 120-150 aH which is not extreme even with the correction on the battery specs. I will change the bulk setting as mentioned to 29. The former settings had been set higher but then the total amp hours by the end of the day solar charging got up to 958 so I began to slowly lower the settings to bring things down. Maybe that's when I initiated the problem I'm currently having? I had been at 32.5 Abs, 27.3 float. I have not done a routine EQbut tried to do that with a 34.0 setting in the last few days but the voltage doesn't go high enough which makes sense since it won't go high enough to go into absorb either. The inverter has gotten hot enough during the last couple of days to have the fan come on. This seems to be unusual in relation to past performance. The fan has not come on. I did check the input to the batteries both with a volt meter and a clamp meter. The readings of those agree with the Classic display readings.

I will run the genny this morning to get things going before the sun comes out. I'll report back later today after both the gen and the sun.
I have only used the generator once and that was to get it hooked up and working in the event that I needed it. There hasn't been a need. These batteries, by the way, Thanks again.

elesaver · July 2016

Huston, we have a problem. I started the generator and the red warning light on the inverter started blinking. Of course, I shut the generator off right away. I've checked everything and don't see any obvious problem. The honda 3000is is only 20 amps to the inverter. And, as I mentioned, I had run the generator successfully in the Fall and haven't needed it since.

I'm not sure what the next step needs to be. Call Outback for help?

elesaver · July 2016

OK, I've taken a breath and will re-group before allowing myself to panic again. I have checked the values in the mate program that I had done before and am not certain that I have all the correct entries. I made a couple of adjustments and tried the generator again but the blinking red light came on again. Any chance that comes on like that until the system "sets up" and then it would be OK? I was afraid to keep it running. Inverters are not cheap and the VFX3524 is not available anymore.

I'll be away for the afternoon so I'll check in again later. Meanwhile, the load is off the batteries and we'll see if we get some charging done today. The sun is quite bright today although storms may come later due to the heat. AbsV is 31.5, AbsT is 4 hours, EA 0.
Thanks again for the help.

vtmaps · July 2016

Which red light? If it's the "ERROR" light, use the mate to read the code... it will tell you what's wrong.

--vtMaps

Vic · July 2016

Hi elesaver,

A running fan on most any good inverter is NOT an issue. Battery charging can be a long slog, and this generates heat inside the inverter, and the fan circulates cooling air. Often ambient temperatures have a large effect on the inverter's need to run its fan. Believe that you are in the South East USA, and might guess that the ambient temps might be higher now, than when you were setting up the system. Also you might not have been doing much battery charging through the inverter, then ... at least perhaps not for an extended period of time.

Also, would suggest running your genset at least every month for 30, or more minutes, with about 50% load on it. Will charge its starting battery, circulate and consume some fuel. Stale fuel is a significant issues these days with that fuel-fouling Ethanol addaitve.

Switch to Grid charging if needed, to get those batteries charged, soon.

Vic

elesaver · July 2016

The red light is the error light. I looked at the comm for errors but nothing is listed. There is no grid so it's the generator only. The values for ac input are set appropriately. Tomorrow I'll go over to the outback forum and see if I can find anything. Something is amiss.

Meanwhile, no generator running but as I said, all loads were removed, AbsV to 30.5, Abs Time to 4 hours and EA to O. I had to be away but the battery seems to be beginning to come back. I could hear the gassing, the voltage was up to 30.5 and absorb was activated. When I checked the aH, the reading was 963! That concerns me but I don't know it if should. I activated force float. It's the SG and the voltage that are the most important but somehow when I see that high number, I freak! The SG is up to 1.23 so I'll have another day or so like this to get the battery up and then try to EQ for 2 hours.

Once I get the battery stabilized again, I'm going to stick with the AbsV at 31.5, Abs Time at 2'15". Those values may seem high but for this particular battery, I believe it's optimal.

I'll post on this again in a few days in follow up. Thanks again. (I'm still concerned about that generator red light!)

elesaver · July 2016

Yes, Vic, I understand about stale fuel and keeping the starting battery of the gen charged up. I will make a point of running that gen a bit once I can get the red light error corrected. Right now, that has me REALLY concerned and I won't be running it until I can figure it out. Thanks for the suggestions.

Vic · July 2016

Hi elesaver,

Thanks for the info.

When you said, " ... When I checked the aH, the reading was 963! That concerns me but I don't know it if should. I activated force float ... ", was that the Remaining Capacity value?

Also, when one Forces Float, the WBjr Net Ah will NOT be reset -- the Classic must decide that it is time to go to Float, and then, it resets the SOC, and Net Ah. YOU can reset these two values by going to the first WBjr Status page (the one that shows the current going into or out of the battery), and hold down the Left arrow on the MNGP, and tap the Enter button. Do not do this very often, myself, but check the Net Ah, and if your system is still in Float (and not Float MPPT), this value should still be 0 for Net Ah.

More later. Vic

vtmaps · July 2016

elesaver said:

The red light is the error light. I looked at the comm for errors but nothing is listed.

Do you know how to read the fault code on the Mate? --vtMaps

Photowhit · July 2016

STOP NOW! and read about charging the batteries and equalizing.

I don't think you have a firm hold on the basics of charging. Your battery, in general, will only minimally out gas during normal charging. The absorb voltage is set so that the voltage doesn't 'run away' and 'boil off' the water out of your electrolyte.

Equalizing should only be done on a fully charged battery. Equalizing is, in essence an over charging of the battery. In tall case batteries, such as your forklift battery, it helps keep your electrolyte from stratifying, having different SG at different levels.

I have no idea where you are reading your AH capacity of your battery, but even with out knowing, I would suggest ignoring it. Almost certainly it has more to do with inaccurate information entered by you than the actual Ah level of your battery.

If you have the grid, you can just use that to charge the batteries through the inverter.

Sorry, this looks like it's a very odd situation, my tone is poor...

Vic · July 2016

elesaver,

SG measurements are the Gold Standard for KNOWING the SOC of a battery.

Please identify several Pilot Cells, and use these as a guide, daily, until you get on top of charging your battery.

Whatever are the readings for SOC and Ah remaining are just noise now, as every day that the Classic does not transition to Float is a day of additional uncertainty of these two readings .. after several cycles without going to Float, it is almost certain that this data is misleading and inaccurate. You have FLAs, which allow easy determination of the SOC, via measuring SGs.

With elevated Absorb voltages, the proper EA reading for your battery will change. But, at a Vabs of about 31.5 volts the proper EA should probably not be above 5% of correct 20-hour Capacity.

Please keep us informed. Vic

elesaver · July 2016

This is just an update of battery status. There have been 2 days with good sun and AbsV increased and Abs Time increased. SG is continuing to improve. Today is rain and little sun so there won't be much happening, I wouldn't think.

The aH total that I referenced in an earlier post is from the WBJr screen. After pressing the status button 3 times, the WBJr screen shows aH remaining. That's where I was monitoring part of the status of the batteries, along with the voltage on the WBJr screen. ( Photowit, I hope this answers your concerns on that. )

The red light issue on the inverter has been resolved. There were no errors listed via the status screen or via the comms so yes, I do know how to read errors on the mate. Since no errors were listed, I wasn't sure how to proceed. After reading through the mate manual, I discovered that the ac in had to be re-set. Reading all the directions has never been a strong suit for me, sad to admit.

So, I'm at the point of getting the SG back up via more charging. Hopefully that will be resolved before too long.

Thanks for all the help and the patience it must take from those of you who have such good knowledge in dealing with those of us who continue to try to learn. Would I be you, I would be bald from pulling my hair out!

Vic · July 2016

Hi elesaver, thanks for the update.

You said, ... "The aH total that I referenced in an earlier post is from the WBJr screen. After pressing the status button 3 times, the WBJr screen shows aH remaining. That's where I was monitoring part of the status of the batteries, along with the voltage on the WBJr screen. ( Photowit, I hope this answers your concerns on that. ) ..."

OK thanks for that clarification.

One thing about the numbers reported by the WBjr, is that each day that the Classic does not make its own transition to Float, (or these numbers are not manually commanded to reset), they generally will drift farther and farther from the real SOC, and Ah Remaining. After several days on no Float transition, they generally will really be totally useless (IMO).

Even on full-charge days, these numbers are generally accurate until the CC produces too little battery/load current to maintain the Float voltage.

Again, IMO, the WBjr is a great addition to the system, but it can only be as accurate as is the data that you program into it. And there are quite a number of other variable factors that would need to be monitored to make this SOC and Ah Remaining better-track what is really going on with the battery.

Again, would IGNORE what the WBjr is saying. It is a great monitor of battery Net current into and out of the battery, and it does a great job in ending Absorb via the Shunt EA setting in the Classic, but the SOC are really just a rough guide. And, for every day that passes since the last transition to Float caused by end Absorb parameters set in the Classic, the less accurate these numbers become.

You have a Hydrometer. It is SO quick and easy to use this, at least on a couple of Pilot Cells to measure the ACTUAL SOC (with good accuracy), that ignoring the WBjr data is no real handicap.

A further note, as the battery temperature (as measured by the Classic BTS) increases above the Reference Temperature, you will see the Remaining Ah increase. This can cause the Remaining Ah to increase above the Capacity of the battery that has been entered during WB Setup.

And do not be too hard on yourself regarding the OB docs, in particular. I have found them difficult to navigate. And several friends and neighbors have OB inverters and Mates, and they have mentioned just how difficult to interpret are the manuals, so it is not just you.

FWIW. Vic

vtmaps · July 2016

Vic said:

One thing about the numbers reported by the WBjr, is that each day that the Classic does not make its own transition to Float, (or these numbers are not manually commanded to reset), they generally will drift farther and farther from the real SOC, and Ah Remaining. After several days on no Float transition, they generally will really be totally useless (IMO).

elesaver, to understand more about why this is so, read this:
http://forum.solar-electric.com/discussion/comment/348328#Comment_348328

--vtMaps

elesaver · July 2016

Thanks for the info, Vic. Weekly SG checking and recording will become part of the routine now. CC info apparently doesn't do much for us.

Photowhit · July 2016

elesaver said:

Thanks for the info, Vic. Weekly SG checking and recording will become part of the routine now. CC info apparently doesn't do much for us.

It does, it's just a new language, it'll take time to learn. Sorry I was so snippy.

Anawa · July 2016

Very good thread. I learn something every time I visit the forum. Thanks.

I would like to follow-up on one of the earlier posts concerning the 20ah rating for the GB batteries. I have 2 ea. GB 12-85-13's and was under the impression that I had 804 ah @ 48 volts. But now, looks like it's only 688 ah, if I multiply the 6 hr (510 ah) by 1.35. Is my current calculation correct?

Paul
in Georgia

elesaver · July 2016

"It does, it's just a new language, it'll take time to learn. Sorry I was so snippy. "

Not to worry, Photowit. Sometimes things just hit us at the wrong time. If you only knew how much I hated posting such basic questions about things on this forum but it's one of the only places to get answers and learn. I'm not too bad in reading things to try to figure something out but it often takes a while to get it and sometimes I just don't have enough background to ever figure something out.

Which leads me to this question about the cc. I realize now that I had been relying on the info there too much instead of following through on not hearing much gassing and the lack of water consumption which, if I'm correct, I can expect to need to add water every 4 or 5 weeks or so. Plus, I should've been checking SG weekly. Anyway, once the values in the cc get "out of whack" due to not going to float, etc., is there a way to get the numbers to be more in line with where the batteries really are? Specifically, my aH reading (WBJr) at the end of the charging day is 963 or so. The manufacturer 20 hr rate (either correct or not from GB) is 938. Unless I can correct that, that number will never even be a guide as to what is going on. Vic explained how to re-set the net aH but it doesn't seem that is what I need. I believe those numbers are shown in a different screen with all the cumulative datum.

I have a feeling that my settings are not optimal at this moment but by watching the SG routinely and adjusting for AbsV and AbsT, I can get settings that are more correct. I also understand that heat/cold influences things as well.

My daily draw down in aH (from the WBJr Screen) ranges from 100-150 aH overnight. Those are easily replaced during the daytime on most days. It would be helpful to be able to have this number as another part of the monitoring process.

The manuals from both Outback and Midnight Solar lack some of the info that I think would be helpful. I understand, though, since the people who write the manuals cannot think like a beginner! :-) One of the chuckles that I get, though, is that Midnight took 3 pages to tell how to unpack the charge controller! Maybe they should retain a beginner to give input as to whether the info is clear or thorough. Just sayin'.

Thanks again for all the help and patience.

Photowhit · July 2016

I'm not big on meters, before understanding.

I suspect what you saw was entering the ah of the battery, real or supposed before the battery had been topped off and initialized. It use to be common once you setup your battery bank, to fully charge the batteries and then to equalized the batteries and take a base SG reading.

Like most battery meters, that are shunt based they reset each time the batteries reach float. If the batteries were say 70-80% charged when you setup your battery monitor, it would look like you are adding to a fully charged battery. Unless it reaches float the monitor never resets. I suspect boB has some improvements to chart the use with the Midnight classic, but I have yet to install my WB Jr. Waiting until I need to reset a few things with the addition of the 3rd array... I've been waiting for a while now lol.

Sorry just taking a break from work.

Vic · July 2016

Hi elesaver,

When one has an issue with a Flooded battery not getting fully-charged (by using measured SGs), would suggest to take SG readings EVERY DAY, at least on several Pilot Cells. And taking several readings in one day, can be helpful. Then carefully rinse the Hydrometer, perhaps four of five times in succession, if it is a Hydrovolt. If you take SGs at the beginning and near the end of a single day, would suggest rinsing the Hydro after the first and last use for the day.

Watching the Shunt Amps reading (charge current into battery) particularly, when you are near the maximum charge voltage point of the day, you can get a quick real-time feel on how fully charged the battery is becoming. This reading would not be too useful during Bulk, unless the battery voltage is nearing the Temp Compensated Vabs (generally).

Did not finish the thought about Resetting the WB SOC and AH Remaining data;
Sometimes, even if the battery has not been fully charged for a number of days, resetting Net Ah to zero could be helpful is seeing the overnight Net. Just realize that that the SOC, and Net Ah are still not close to reality, in all probability, just looking at weather you are gaining ground on Net Ah.

BTW, am still using Classic FW 1849 on all Classics here. There might have been some additions to the info available from the WBjr Status screens in the past several years ... will try to UD to the latest FW SOON.

AND, please do not be reluctant to ask questions or curiosities that you have. We are all learning, and have some questions. Questions asked will help others who have similar questions, now, and into the future. In the area of battery charging and maintenance, there are generally only areas of grey, and not very many absolutes, generally.

Hope that you will have sunny days ... and hope that you will get the situation with the genset ironed out. Having a genset available will be an essential tool for you (obvious, isn't it?).

Happy Independence Day USA. Good Luck, elesaver, you are asking good questions. Vic

Stumped on SG values not increasing

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