Corrective Equalization for newly installed Rolls batteries

tonygcan

Hello all,
I installed last Dec 2012 my solar system in my residence.
Xantrex MPPT CC
Xantrex XW 4548 Hybrid Inverter
8 units Rolls 450 AmpHour 6 volt batteries
12 Sharp 185 watt solar modules

Upon commissioning of the system I went through an initial equalisation of the batteries. I did not have a hydrometer though and I wasn't able to take any SG readings.

Last week I got hold of a hydrometer and measured the SG of the batteries and discovered that most of the batteries at full charge read only about 1.190 - 1.230.

I read up on the Rolls manual and read about corrective equalisation. I then filled my batteries with distilled water and went through the equalisation cycle using the XW4548 and the grid. I found that I had to repeat the process 4x for most of the cells to read a higher SG reading. I still did not get the desired 1.265 for most of the cells but most of them read from 1.235-1.265.

After 1 week of use I checked the cells today when the batteries had gone into float from the MPPT and most of the cells are in the 1.200-1.400 range with a few reaching 1.265.

Are my batteries shot?

I shipped them to the Philippines from Arizona in the states dry. It probably took 2 months from the US to the time of commissioning when I added the acid and installed the batteries.

Is there a way to get the SG values up or am I stuck with the low SG levels?

Thanks in advance for any input.

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

The only way you'll ever get them up is to keep on hammering them with EQ's. You added the acid so they would have been as new that day, the shipping time had nothing to do with the problem now. I assume they shipped you the acid with the Batteries and it would of had the correct SG ?? I'd use around 62 V EQ and watch the temperatures of the batteries, don't let them go above 115-120 deg F. , I 'v had them take 18-24 hrs before on some batteries.

Set your daily absorb voltage and time up, you know you are deficit charging and they are getting worse. I'd use it at at around 60 v and 3-4 hours until you can walk the time and voltage back.

Do you have a way to break the bank up and EQ a couple at a time ?? You say they they are 1.40 - 1.265, so if you could break them up you work on the low ones.

They are in a death spiral, up have a big turn around to do.

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

Thank you Blackcherry for the heads up. Yes, the acid shipped with the batteries. As regards to breaking up the bank, I probably could but I wouldn't know how to set it up and equalise separately. I will try to do some heavy duty equalisation now that I've gotten feedback from you.
Would you know how to set-up the XW4548 to equalise at a higher voltage and for longer hours? As it works now I just press the equalise button and it does it automatically.

At least now I know that I can equalise up to 18 hours. That's good to know. I now am actually getting more juice from the batteries and hope to squeeze even more after a thorough equalisation.

I will also adjust the absorb voltage on the MPPT CC.

Thank you.

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

You should be able to set the EQ voltage in the SCP, I think you might be stuck with time and re-trigger it. You need to WATCH the Temperatures don't let them get above 115-120 you'll be fine. I take the SG reading every 30 minutes or so and as long as they are rising your ok. 18 Hrs is a long time, but if that is what it takes, so be it.

What is the voltage at your Batteries ?? Are you doing the EQ with the Charge Controller ??

mike95490

Re: Corrective Equalization for newly installed Rolls batteries

Your cells seem to have spent a LOT of time undercharged, and sulfation may have already set in.

Shed some loads till you get them boosted back up. If you have a generator, run it for a hour or so, in the AM, before the solar kicks in, and you get the most amps for the fuel you burn. And if the batteries stay cool enough, hit the EQ button a second time, to try to save the batteries.

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

The voltage at the batteries is 50.6 at full charge. Before the equlisation last week they would be about 48.1 in the morning. After the equalisation the batteries have read about 49.3 in the morning. I am using the XW4548 hybrid inverter through the grid to equalise the batteries.

Mike, I am connected to the grid and use my solar system to supply power about 30% of my requirements. We don't have the facility to sell to the grid in the Philippines. So I am using the system like an off grid system to supply a portion of my requirements with the advantage of having the grid as support.

I will start an equalisation cycle tonight again, do it twice and then again in the morning.

Thanks.

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

Tony, your going to have to get the manual out and do the Custom Battery settings in the SCP and set the EQ voltage. With Grid , you shouldn't have a problem. It will do a Full charge first , then start the EQ for the hour.

I thought maybe you were doing the EQ with the CC. Confused.......

Attachment not found.

Cariboocoot

Re: Corrective Equalization for newly installed Rolls batteries

Couple of points to add:
1). What is the Absorb Voltage set at? It should be 60 for those Surrettes.
2). What is the Absorb time limit set at? It should be 4 hours, possibly more, preferably with an End Amps setting around 5 or 6.

Equalization is not a substitute for proper charging. If the batteries aren't going through a complete Absorb cycle at the right Voltage before being equalized the EQ process is a waste of time.

NorthGuy

Re: Corrective Equalization for newly installed Rolls batteries

tonygcan wrote: »

Would you know how to set-up the XW4548 to equalise at a higher voltage and for longer hours?

XW will only equalize for 1 hour. So, you need to trick it. I did it by setting Float voltage to 64V (or whatever you want for equalizing) then started charging. Make sure that you select "3 Stage" charging too. As soon as it gets to "Float", you'll be equalizing. It will be doing this forever, so you need to stop it manually. You can do that by changing Float voltage back to what it was.

You can measure SG every hour. If it stops changing, you probably want to stop equalizing. Make sure to monitor battery temperature too. Batteries may overheat.

You say you added electrolyte by yourself. Did you measured it accurately? Did you stirr it before adding? If you put a slightly different amount of electrolyte into different cells, then topped with water, the SG in different cells will be different.

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

NorthGuy wrote: »

You say you added electrolyte by yourself. Did you measured it accurately? Did you stirr it before adding? If you put a slightly different amount of electrolyte into different cells, then topped with water, the SG in different cells will be different.

I had that feeling early on, that there may be a issue with the SG's. It's hard to do a tutorial on here, so many details for something so simple.

Vic

Re: Corrective Equalization for newly installed Rolls batteries

HI Tony,

Just trying to clearly understand a few things;

1. OK so Surrette shipped the batteries to AZ in a dry state, and shipped the electrolyte in separate containers??

2. You shipped these batteries still DRY to the Phillipines?

3. And then in December you added the Surrette supplied electrolyte to the battteries for the first time, and then you proceeded to follow the Surrette ACTIVATION insructions(??) -- which may be a bit difficult to do WITHOUT a Hydrometer(!).

4. Did that activation go as described in the Surrette Activation instructions?

5. You mentioned that the highest cells that you measured were 1.400-ish. Wat this a typo?? Did you mean one point four zero zero???

You do need to get these batteries fully charged, and then EQed. Since there is a single string of batteries, as I read it, without an external lower voltage batt charger, does not seem that breaking up the string and charging lowest batts separately would be possible, IMHO.

More Later, Vic

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

Thank you North guy, Blackcherry and Vic, now I know how to trick the XW into equalizing.
Vic, it's exactly how you described it. My integrator is the one who added the electrolyte to the batteries and I wasn't around when he added them. I presume he did it correctly but since the values are so different from one cell to the other then it's entirely possible that the cells have different electrolyte levels.

Is there a way to correct this situation or if the levels are different am I doomed to have botched the process for my batteries forever?

Sorry Vic, just re read your post. Value was not 1.4 but 1.24.

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

tonygcan wrote: »

Thank you North guy, Blackcherry and Vic, now I know how to trick the XW into equalizing.
Vic, it's exactly how you described it. My integrator is the one who added the electrolyte to the batteries and I wasn't around when he added them. I presume he did it correctly but since the values are so different from one cell to the other then it's entirely possible that the cells have different electrolyte levels.

Is there a way to correct this situation or if the levels are different am I doomed to have botched the process for my batteries forever?

There are 4-5 ways to deal with The Electrolyte , none easy. The first thing you need to do is to get them all up to the Maximum SG that you can get. Then you would have choices. Once the SG's no longer rise one could assume that all the sulfate has been removed from the surface of the plates. I wouldn't get to excited at this point.

1) You could dump it all out and add fresh with the correct SG.
2) You could dump it all out and re-mix what you have by adding pure Acid to raise it or Distilled water to lower it, then put it back in.
3) You could adjust whats in them by removing Electrolyte and adding distilled water to lower or adding Pure acid to raise the SG.
4) After all of the above your still going to have to see how they all balance out.

I'd keep on EQ'ing them and see what you can do and contact the person that filled them and see what they did. I still wish you had the equipment to do the lowest by them selves so you didn't have to abuse all 8 at the same time. You might check around and see if you can borrow a charger that can EQ at a lower voltage and do a couple at a time.

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

Sounds like an interesting process BC. Ü
The results are encouraging, the lower values are increasing after my 3rd equalization.
When the electrolyte and the distilled water mix do they mix completely? In that case could I siphon a little at a time of the mixed solution and check the value and either add electrolyte of d. Water depending on the value?
Also, is it ok to use distilled drinking water?

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

Sorry Blackcherry, I see you actually answered my question with option number 3. Ok, so if it's a mixed solution it's called electrolyte, separately it would be acid and d. Water?

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

tonygcan wrote: »

Sounds like an interesting process BC. Ü
The results are encouraging, the lower values are increasing after my 3rd equalization.
When the electrolyte and the distilled water mix do they mix completely? In that case could I siphon a little at a time of the mixed solution and check the value and either add electrolyte of d. Water depending on the value?
Also, is it ok to use distilled drinking water?

Yes, they will mix completely when you EQ and are getting a " Boil " ( good Bubbles ). The only problem mixing More electrolyte in is that if it " 1.265 mix" , It'll take a fair amount. I buy mine from a battery re-cycler for $10 for 5 gallons, bring your own bucket. He'll add pure acid and set the SG I want after it's filtered.

But you don't want to mess with that until you hit the wall on the EQ, other wise you'll be chasing a moving target and you'll do more harm then good. if you try mixing now and there is sulfate on the plates it will keep changing the SG and you'll get lost on where you want to get.

Vic

Re: Corrective Equalization for newly installed Rolls batteries

Hi Tony,

YES, you should check with the person who added the electrolyte to these batteries, and ask , "just how did you do this?" Preferably without any additional info, you just want to know the exact process.

During most full Absorption cycles, the electrolyte is fully mixed, BUT for the cells with low SG, there may be less complete mixing. After an EQ, there is a better chance of full mixing. Yes you could use your Hydrometer to remove some of the electrolyte from cells that seem too high in SG.

Never use ANYTHING BUT Distilled Water (preferably referred to as Steam Distilled, or made by Steam Distillation or similar).

Drinking Water is usually not distilled, as it can remove Minerals beneficial to humans. Use the absolute best water that you can find, as any residuals will remain inside the batteries forever, and some of these are harmful. Good Luck, Vic

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

tonygcan wrote: »

Sorry Blackcherry, I see you actually answered my question with option number 3. Ok, so if it's a mixed solution it's called electrolyte, separately it would be acid and d. Water?

Thats correct The SG is the ratio of the Mix. When the battery has " Low " SG, part of the Mix is on the surface and in the pores of the lead plate in the form of Sulfate. You are trying to Re-combine back into the electrolyte = Mix.

NorthGuy

Re: Corrective Equalization for newly installed Rolls batteries

Hopefully, the job was done correctly, you get your SGs all the same after good equalization, and you won't need to do changes.

The drinking water is usually not distilled. I tested drinking water sold around here and it contains 35 ppm of dissolved solids. You can ask the person who activated the batteries where to get distilled water.

waynefromnscanada

Re: Corrective Equalization for newly installed Rolls batteries

In these parts, WalMart and most drug stores have distilled water.

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

Cariboocoot wrote: »

Couple of points to add:
1). What is the Absorb Voltage set at? It should be 60 for those Surrettes.
2). What is the Absorb time limit set at? It should be 4 hours, possibly more, preferably with an End Amps setting around 5 or 6.

Equalization is not a substitute for proper charging. If the batteries aren't going through a complete Absorb cycle at the right Voltage before being equalized the EQ process is a waste of time.

Hi Cariboocoot, could you advise what setting bulk, float and equalize voltages should be for my batteries? Thanks.

waynefromnscanada

Re: Corrective Equalization for newly installed Rolls batteries

There is no voltage setting for Bulk mode. During Bulk, the controller is dumping all available power into the batteries, trying desperately to get them charged enough to bring the voltage up to the Absorb Voltage setting, which Cariboocoot states should be set at 60 volts in your case.
I'm sure he'll be back to you with Float and Eq voltages.

Vic

Re: Corrective Equalization for newly installed Rolls batteries

Tony,

I am not coot, BUT, normally any charger that has a Bulk V setting would have it set to the Absorption V -- there are some exceptions, but this is the customary setting.

You may well need a longer Absorption and at a higher voltage now, while you are trying to get the battery's SG up. It is conceivable that 60 V may be OK for Absroption now, but that IS high, and would not normally be set that high for normal operation. Right now you DO need a long absorption stage, but later would expect your absorption V to be in the 58.5 ish volt range. Tha absorption time depends upon the Depth Of Discharge of the battery bank. You should be able to find a voltage and time for Absorb that averages in getting the battery fully charged several times per week or more often. You are on the Grid, so you may fully recharge the bank more often than that.

Would use Surrette's recommendations for Float V, (about 52.6 V the last I saw) and would make certain that the EQ voltage is at or above 62 V. Normally one would EQ a battery bank until the SGs stop rising, and continue for another 30 or so minutes. Of course, during very long EQs, battery temepratures can rise to a point where the EQ should be stopped and the batteries allowed to cool. Always monitor electrolyte levels before and during an EQ if it is long duration.

All of the noted voltages should be Temperature Compensated.

And, if you happen to add additional higher SG electrolyte to a battery that is not fully charged -- one with sulphate still on the plates -- you might never be able to get that sulphate off of the plates. The higher the SG of that cell/battery becomes, the more difficult it is to get the sulphates back into solution. If this happened, that cell/battery would loose capacity, which might never be recoverable.

EDIT: The Xantrex/Schneider XW stuff DOES have a Bulk V setting. Some do use this for a higher V Absorption just before the real Absorption stage starts. Most do not, and set this Bulk V to equal the Absorption V.

Opinions, Vic

waynefromnscanada

Re: Corrective Equalization for newly installed Rolls batteries

Vic wrote: »

Of course, during very long EQs, battery temperatures can rise to a point where the EQ should be stopped and the batteries allowed to cool. Vic

Note of interest: two years ago this Summer, my MX-60 somehow locked up in the auto on EQ mode. Knew in the morning it was in EQ when I checked on it. Was stunned when I came home late in the afternoon, found it still in EQ mode and the batteries were actually hot! WOW! I expected battery failure after that, but so far they still seem OK.
I had to do a shut down, complete removal of power, and restart of the MX-60 to clear the problem. Hasn't happened again - - so far.

RCinFLA

Re: Corrective Equalization for newly installed Rolls batteries

Batteries are not necessarily 'new' from point you put in electrolyte. Most all batteries are built with a process that preforms plates at factory. This means the plates have been soaked with electrolyte.

For shipping, and several months of storage, the 'dry charge' batteries should be filled with distilled de-ionized water. This is drained out then electrolyte install upon installation. Overall, a real pain to do.

You do need equilization but don't over do it at one time. Watch the battery temp and don't let them get too hot. Monitor individual batteries and stop if one battery gets above 7.75 to 8 vdc as that battery will overheat. If there is too much voltage differential between batteries then break them up and match pairs as close as possible and charge with a 12 v charger to 15 vdc for equalizing. You need to equilize at 60 vdc for the full stack but watch individual battery voltage.

tonygcan

Re: Corrective Equalization for newly installed Rolls batteries

Thank you all,
I am happy to report that all of the cells are now at 1.50 or higher. A BIG improvement from yesterday. Thank you for all the tips. I will adjust the charge controllers settings for now and reevaluate after a week or two.

I plan to equalize 2 more times but since it is noon time now I will wait until late afternoon to avoid getting the batteries too hot.

Blackcherry04

Re: Corrective Equalization for newly installed Rolls batteries

tonygcan wrote: »

Thank you all,
I am happy to report that all of the cells are now at 1.50 or higher. A BIG improvement from yesterday. Thank you for all the tips. I will adjust the charge controllers settings for now and reevaluate after a week or two.

I plan to equalize 2 more times but since it is noon time now I will wait until late afternoon to avoid getting the batteries too hot.

Congrats Tony, just stay on the road and don't run off in the weeds, you'll be fine. Batteries react to 3 things, Voltage, Time and Current, a change in one effects the other. Sg's are your constant, it's the home point you always want to return to.

petertearai

Re: Corrective Equalization for newly installed Rolls batteries

Hi wayne, The fm80 will stop the eq if the battery temp gets to 50 deg, maybe the mx will also? I know too hot but at at least a safety stop.

waynefromnscanada

Re: Corrective Equalization for newly installed Rolls batteries

petertearai wrote: »

Hi wayne, The fm80 will stop the eq if the battery temp gets to 50 deg, maybe the mx will also? I know too hot but at at least a safety stop.

Yes, I've heard the FM-80 has that feature, which is great. Unfortunately if the MX-60 does, I'm not aware of it. BTW the batt temp sensor IS installed, and was operational at the time.
Now in Summer I switch the MX to manual EQ and control it myself. Not a problem in winter, the days are too short for things to go off the rails that way.

Ralph Day

Re: Corrective Equalization for newly installed Rolls batteries

"Note of interest: two years ago this Summer, my MX-60 somehow locked up in the auto on EQ mode."

Wow Wayne, I didn't even know there was an auto mode for EW on the MX60. Of course, mine's really old, first year of production I think.

My neighbour had 2 bad cells in 2 different batteries in 2 different strings...L16's. When he got to them the electrolyte temp was 80C. No fire, but boyhowdy. Only 2 of the 16 batteries were usable for anything after that.

Ralph

Cariboocoot

Re: Corrective Equalization for newly installed Rolls batteries

Or "why I don't like automation, reason # 6,327".

ChrisOlsen went into quite a lot of detail of his adventures with Surrette batteries and how it was necessary to put the Voltage well above normal for them to work properly. It's on the forum somewhere. One of the many things I can't find.

Anyway, yes the Xantrex uses "Bulk Voltage" for Absorb; the point at which the charging switches form one stage to the other.
If I recall the numbers for Surrettes are freakishly high. On a 48 Volt system it's like 60 for Bulk/Absorb, 56 for Float, and 62 for EQ. But you have to temper these Voltages with your own batteries' performance, specifically watching for excess water usage (a subjective criterion) and dialing back if it's too much.

One thing Xantrex got right is limiting EQ to an hour. You really do not want to run above normal Voltages for hours on end as that will heat the batteries up and could cause more damage. Right Wayne?