S550 new and not lasting

fog

Hi all. I am new to the forum. 

I live off grid with no grid ties. 

I have a Schneider conext SW 48v inverter and an Outback 60 controller with 9 Canadian solar 330 watt 24 v Panels. They are hooked up in series of 3’s. I’ve bought new batteries last year in the fall - 8x Rolls Surrette S6 L16 HC 6V (formerly known as S550) 445 ah. 

Over that winter they were excellent. Go to bed with 50.9 volts and wake up with 49.8 volts. All was good until one day in the spring I added distilled water as per schedules maintenance and immediately after turning system back on the overnight voltage dropped to about 48.8 at bedtime and 45.7 in the morning. I think that sounds crazy because that shouldn’t make any difference and could just be coincidence but it is fall again and I’ve had to run my generator several times even during the summer when I normally never do to daily now that the sun is less. 

I’ve never equalized the batteries and am not sure how to. Can someone please help. Thanx 

fog

Forgot to mention my loads are a very small freezer and bar fridge and satellite internet that are on all the time. Before this happened I had 2 bar fridges and I removed one to lighten the load to see if it would help but it made no difference. 

mcgivor

Welcome aboard @fog

Usually an equalization is performed before the batteries are put into service AKA commissioning, the thing to do before anything else is to take specific gravity (SG) readings with a hydrometer to determine the condition of each cell. Rolls Surrette has extensive information on their website regarding charging setpoints, SG and when to equalize.

The controller has its own instructions on how to perform an EQ which can be found in the manual, the SG readings will provide more information than can be derived from voltage readings alone. By far the most common problem is cronic undercharging, however as no information is provided it's impossible to speculate what, if anything has gone wrong.

Post your charging settings, wether temperature compensation is used, if SG readings have been taken as part of regular maintenance etcetera, etcetera. The more information the better, this is a very common phenomenon with new users, hopefully things can be resolved and you are correct the voltages don't look good ar face value.

 

Dave Angelini

Good advice above to go to the surrette website and learn before you have to write a big check.
45.7 is bad for that load if you really are charging correctly, you probably are not.

New_Mexico_Will

When you say it was 50.9 when you went to bed, is that the highest voltage you see?  That's way too low.

706jim

I have a similar system using Trojan L16's set up for 24 volts. Originally I had setpoints of 26.4 float and 28.2 bulk. Other posters suggested increasing these values. I presently use 29.8 bulk and 27.6 float and capacity seems much better. If you try this change your values would be 59.6 and 54.8 a lot higher than I think you're using now.

Dave Angelini

I would do what Jim wrote right now and also set absorb for 4 hours.

Learn your battery from the surrette site, get a hydrometer, and get ready to do some long EQ. Get moving on this as winter is coming fast.

 If you are lucky you probably can save them. They are built to take this kind of abuse a few times.  After that, you write a check.

Photowhit

fog said:

Hi all. I am new to the forum. 

I live off grid with no grid ties. 

Welcome... I live similarly, with no generator backup...fog said:

fog said:

I have a Schneider conext SW 48v inverter and an Outback 60 controller with 9 Canadian solar 330 watt 24 v Panels. They are hooked up in series of 3’s. I’ve bought new batteries last year in the fall - 8x Rolls Surrette S6 L16 HC 6V (formerly known as S550) 445 ah. 

Nice sized system, and at a quick glance looks well reasonably balanced.  An array of 2970 watts charging a 48 volt,  428ah (20hr) battery bank, or roughly a 9-10% charge after allowing for panel label vs NOCT values.

fog said:

Over that winter they were excellent. Go to bed with 50.9 volts and wake up with 49.8 volts. All was good until one day in the spring I added distilled water as per schedules maintenance and immediately after turning system back on///

///the overnight voltage dropped to about 48.8 at bedtime and 45.7 in the morning.

Not sure I've ever turned off a system to add distilled water, I suspect something happened at this point. Do you monitor your system during the day? Does it go through the basic stages of charging? Here's basic charging cycle info;

During charging, there are basically 3 stages of charging, Bulk, Absorb, and Float.

BULK;

First thing when charging starts you will be in bulk, the voltage rises from what ever the system voltage was to a set point, around 14.5 volts. At that point the Charge controller stops the voltage from rising. Higher voltage can damage sealed batteries.

ABSORB;

Once the battery hits the preset point the charge controller keeps it at that point. Your batteries are roughly 80% full. Flooded batteries will start accepting less current at 80-85% full AGM/Sealed may go a little longer before accepting less current.

On many controllers you can set this point, Some will have different presets for Flooded, and sealed batteries, or flooded, AGM, and sealed batteries. 

The charge controller has a couple ways to know when to switch to float, Most inexpensive Charge controller are just timed for 1.5-2 hours. Some will also see less current flowing through the charge controller and shut it down when minimal current is flowing through the controller. On more expensive charge controller. You can set battery capacity to give the Controller a better idea of when to stop. you can also set a longer Absorb time. Or set 'end amps' a amount of amps flowing through the charge controller to stop Absorb and switch to the final stage.

FLOAT;

Once the Controller has determined the battery is fully charged it reduces the voltage to a point where very little current is flowing to the battery. This will prevent the battery from over charging and heating up.

While in 'Float' the charge controller watch for voltage drop, which would indicate a load. If the voltage begins to drop the charge controller will allow as much current to flow from the panels/array to compensate and maintain the voltage. If the voltage can be maintained, the load will in essence be running directly off the array/solar. If the voltage drops below the preset float voltage, the controller may start a whole new cycle if it stays there for a period of time.

The system voltage drop you see at night when the sun goes down is the charge controller moving into a resting mode with no energy to contribute to the system.

The morning voltage may reflect a load present that is effecting the voltage level.

I don't use the Outback 60 amp charge controller, but worry you may have lost your settings perhaps the default settings are for AGM batteries which would want lower values to ensure they don't over heat.

fog said:

...I’ve had to run my generator several times even during the summer when I normally never do to daily now that the sun is less. 

I’ve never equalized the batteries and am not sure how to. Can someone please help. Thanx 

I would first set correct values for your batteries according to your manual, Here's is Rolls general manual, yu may also check for a Rolls S550 PDF and see if they have any added info.

https://rollsbattery.com/public/docs/user_manual/Rolls_Battery_Manual.pdf

Rolls recommends a higher charging voltage than most manufacturers. We've had someone here contact them and they recomended very high equalizing voltages (being sure that a temperature probe was in use, both your inverter and charge controller should have them!)

Here is a screen shot from the manual linked above;


So your bulk/absorb value should be 60 volts, float at 54. I'd suggest going to 4 hours on absorb as Dave has suggested. These are all settings on your charge controller. I think they can be done without Outback's hub, but I'm not sure, you may have a hub or know. I think with either, you need to remember to hit send! after making changes or they will just revert back (which I think has happened) I think this is usually stored on eprom, but maybe there's a battery for memory... Sorry, I've not used Outback CCs.

Equalizing at 62.4-63.6 (I suspect they put in the lower value because some inverters don't like values above 63 volts, I would use the higher value, so long as you have a battery temperature sensor attached)

To equalize you first must fully charge your battery bank, I would start by running your generator early in the morning so that you have reached absorb by 8 or so, then watch to see how many amps are flowing to the battery bank, I think you can do this from the charge controller (CC), you will have things running, and perhaps you can just stay inside and run out when the fridge kicks off, or just turn it off. Once your sending less than 2% of you battery capacity or about 9-10 amps to the system, start equalizing. There should be a setting on the CC, set it for 63.6 volts is my suggestion. Once equalizing starts the current going through the CC will increase. 

You can check the specific gravity before you start equalizing, but even if the cells were even, I would encourage you to do an equalizing for battery health, after 2 hours check the cells and the first go, write them down. You are looking for particularly low cells. If cells are recorded as less than full capacity, go another hour and check. Continue until you see no improvement over 2 hours... This time of year you will run out of daylight likely. I'd just let it go and start again the same way the next day.

Rolls includes this info in the manual;
Periodic equalizations may not recover a loss of capacity from a build-up of sulfation over time. Repeated equalizations may be required in situations where the battery bank has been consistently undercharged. Recovered capacity, generally partial, may take 1-3 months with battery banks low specific gravity measurements.

I encourage you not to give, up and perhaps each weekend until you don't see improvement. Rolls makes pretty good batteries, I suspect they may have been undercharged for quite a while. but they are young, and they are likely to bounce back nicely!

There is information in the manual about what you are looking for in SG readings under corrective equalizing.

Photowhit

BTW - might be worth checking, but I'm pretty sure Conext inverters can go to 66 volts(or higher) without complaining. I think they and Magnum can handle the broad charging range of Nickle Iron batteries (from my feeble memory) If so you can just leave your system on through the equalizing.

You should also set the correct bulk/absorb setting in your inverter/charger!

mike95490

Are you sure the water was "really" distilled water, and not spring water or purified drinking water ?

But like others, I suspect a system setting got reset to a default and needs to be configured again.

fog

Yes distilled for sure. I checked all my settings and they are the same. I just got a hydrometer so I’m gonna do a gravity check this weekend. My system hasn’t floated or absorbed in a while. Just not enough daylight. I want to equalize the batteries so do I run my generator the whole time?

Photowhit

fog said:

Yes distilled for sure. I checked all my settings and they are the same. I just got a hydrometer so I’m gonna do a gravity check this weekend. My system hasn’t floated or absorbed in a while. Just not enough daylight. I want to equalize the batteries so do I run my generator the whole time?

At least long enough for the bank to reach absorb stage, as I wrote above... Perhaps an hour longer, as the battery will slowly absorb less.

You can check the output through the charge controller to see what the array is giving you on a sunny afternoon before you hit absorb. It would be good to know your array hasn't lost a string! An array of 2970 watts should be outputting around 2200 watts in the 2 hours either side of solar noon. Perhaps a couple hundred more on a cold day or less if hot and dusty panels

Since equalizing is done on a full battery, there isn't a huge need for a lot of power. If you find the voltage drops off from the equalizing voltage you might start the genny, but you should be fine.

Check the setting on you inverter as well as your charge controller, and set them to the settings in your battery manual, I provided a link above. They are higher than typical flooded batteries.

You will want to have 2-3 gallons of distilled water on hand during the equalizing runs.

BB.

When filling batteries before a full charge/equalize cycle... Make sure the plates are covered to something like 1/2 full.

If you fill the batteries cold, the charging, heating (fix typo) of batteries, and gasing can cause the electrolyte level to rise more and bubble out the to of the cells.

So do not fill to fill line until the end of the charging cycle.

And while you want 10% to 13% or more current during bulk... For equalize charging 2.5% to 5% rate of charge is usually enough. A large genset doing equalize charging can waste a lot of fuel (gasoline and propane generator engines generally consume 50% fuel flow at 50% to 0% genset loading.

Using solar or a smaller genset for equalize charging is more cost effective.

Bill

Photowhit

Yes, Bill is right. generally you just want to be sure the plates are covered. Once through you will want to top off the cells or at least ensure they are covered if you will be continuing the next day. You should expect the cells to "out gas" this is a natural effect of the controlled over charging of the battery (that is what equalizing is!)

An explanation here;

https://www.mathscinotes.com/2013/02/battery-outgassing-math/

fog

When you say “lost a string” do you mean a bank of batteries?
i only have the one bank of batteries. That is 8- six volt 445 ah batteries for 48 volt system. Thanx

Photowhit

fog said:

When you say “lost a string” do you mean a bank of batteries?
i only have the one bank of batteries. That is 8- six volt 445 ah batteries for 48 volt system. Thanx

Photowhit said:

You can check the output through the charge controller to see what the array is giving you on a sunny afternoon before you hit absorb. It would be good to know your array hasn't lost a string! An array of 2970 watts should be outputting around 2200 watts in the 2 hours either side of solar noon. Perhaps a couple hundred more on a cold day or less if hot and dusty panels

You can check to see what the "solar array" is producing.  Each set of 3 solar panels is considered a 'string'. This is the reason I gave you a rough idea of what to expect from the array. I believe you should be able to 'see' this on the Outback CC, the Hub, or Mate(?).

Photowhit

If you don't know the output of your array, it should be checked!

You could have lost 1 or 2 strings and the charge controller, would still be trying to charge the battery back through the remaining string.

Usually it's a connection problem, the panels are very reliable, but people aren't lol. If your output appears low, check the breakers in you combiner box, then check the breakers ahead of your charge controller (if you have them), Then check for connections that have become loose or disconnected. MC4 cables lock in quite well, but that's the last spot I'd check, requires tools (generally), and still can break trying to disconnect. So look for wires cut or pulled out at the breakers as well as if the breaker is flipped first.

BB.

Some folks put parallel "strings" of batteries together to make a larger bank (or you can use large AH batteries in fewer or even one string banks).

But Photowhit was typing about parallel connected solar panels (or series strings of panels connected in parallel:

You can check the output through the charge controller to see what the array is giving you on a sunny afternoon before you hit absorb. It would be good to know your array hasn't lost a string! An array of 2970 watts should be outputting around 2200 watts in the 2 hours either side of solar noon. Perhaps a couple hundred more on a cold day or less if hot and dusty panels

For example, if you "lost" a string in a 4x parallel connected set of strings--That is just a 25% reduction of array power.

And it is very difficult to just look outside and see if your array lost 25% of its capacity (just variations in sunlight--Haze, high clouds, dust, etc.) can cut output of an array by 50%--And your eye may not even see the difference.

Also--With off grid systems, the solar charge controller + battery bank can take less than maximum array energy (a bit of time on bulk--maximum array wattage--And 4 hours of Absorb and the rest of the day on float). And you would never notice the disabled string until you happen to look the the data during bulk charging.

If you have breakers in a combiner box... You can cut out one string at a time (say 4 strings at 40 amps total from array--Then cutting one breaker at a time will reduce your harvest by 10 amps)... Or you can get a DC Current Clamp DMM and measure the current from each series string--This is actually quite quick and easy to do (if you can easy access one leg of wiring for each string).

And you can do the breaker or DC clamp meter tests in any stage of charging (bulk, absorb, float) and during any time the sun is up.

A property operating solar array--Each series string should be carrying about the same current as its neighbor (at the same time, same direction/tilt, same sun, same temperature, same charge controller input).

It is not unusual for a solar panel to fail, or a bypass diode to short, or J-box or other wiring connections to fail (water, chewing animals, moisture in box, overheating, loose connections).

And example of DC Current Clamp DMM (digital multimeters--And really AC+DC current clamp DMM). Note links are starting points--Do your research and ask questions:

https://www.amazon.com/UNI-T-UT210E-Capacitance-Multimeter-Resolution/dp/B075ZHDQFP (cheap/good enough for our needs)
https://www.amazon.com/gp/product/B019CY4FB4 (more expensive mid-priced meter)

-Bill

fog

Ok so I have breakers on each set ( string) of panels. When I flip them off individually I can see on the outback the volts and amps go down. So would it be safe to say they are connected? 

BB.

For solar panels, in general (same sun, no shading), each string of panels should carry an equal fraction of current...

If you have 12 amps total, and 4 parallel strings of panels, switching off one breaker at a time should reduce the total current by 1/4 (or 12/4=3 amps). Identical solar panels in parallel are usually very close to identical current.

Turn off breaker A, drop 3 amps. Turn on breaker A and turn off breaker B, 3 amps, etc... If all are close, then the array and its connetions are good.

If you find a string with zero current (or less than 50% than the average current of the other strings), you probably have a bad panel or connection.

If you see a 10% or less difference between strings--Then probably all is well.

-Bill

mike95490

I used my DC combiner box, also as a DC switch box because I had the extra space in it.

Vic

Hi fog,

We all look forward to your   SG readings.

And agree,  that your Absorb voltage and time looks suspect  (too low).  Please DO check,   and report Absorb/EQ/Float voltages.

Here is a good article from Surrette on measuring Flooded battery SGs:
http://support.rollsbattery.com/support/solutions/articles/4347-measuring-specific-gravity

Personally,  would suggest adding Distilled  Water to the batteries,  during Absorb,  early enough to allow about 30 additional minutes of Absorb remaining when finished adding water to the last battery.    This allows the Gassing of Absorb to mix the added water into the existing electrolyte.

An alternate   method to allow mixing,   is to do a short   --  30 minute  --  EQ,  at the Absorb voltage,  or a bit  higher.

This mixing can be particularly important,  as  Flooded batteries age (realize  that the subject batteries are youngsters).   Would never add make-up water during Float personally.

Just another opinion,   Vic

Ralph Day

I have S550's as well.  They're about 18months old now.  At first it seemed they needed lots of amps to absorb.  The algorithm for determining absorb time led me to 6 hours absorb.  That's after having CS type 8v surrettes which I killed by only absorbing for 2-3 hours (it took 15 years mind you).

Watering is only needed every 2 months, about 100-200ml per cell per time.  I usually give them a bump to bubble the new water in, unless the day is going to be sunny.  I don't cycle very much...HBX on Outback 3648 inverter so only about 2 hours absorb to reach 2 amps charging.  If cycled in the summer it takes the full 6 hours from a 20% discharge.

Ralph

fog

Ok I’m going to run generator all day today to get batteries through all cycles to equalize. Do I have to unhook all my loads to equalize?
also when do I take my gravity readings? 

mcgivor

The general concensus is to equalize with no loads so as to get to the target voltage then keeping it there without deviation, not really convenient,  but worth doing as it's it's generally a one or two times per year or less event,  assuming  the charging regime is keeping the SG readings at satisfactory levels.

fog

My settings on the outback are 54 float and 60 absorb. Equalize at 63.5. Right now I’m running genny and outback is saying Mttp bulk and volts are 59.1. Am I right to assume it will eventually float then absorb?

fog

I can also see from the outback log that my system hasn’t floated or absorbed for 59 days. 

mike95490

fog said:

I can also see from the outback log that my system hasn’t floated or absorbed for 59 days. 

That's not good.  The absorb stage is critical to get the battery above 80% full to drive off the sulfur crystal deposits before they harden into permanent sulfation.

fog

So I’ve been running generator for 4 hours now and it’s still MPPT bulking. Outback says 59.0 volts. Do I just keep going until it starts to absorb?

Photowhit

fog said:

Ok I’m going to run generator all day today to get batteries through all cycles to equalize. Do I have to unhook all my loads to equalize?
also when do I take my gravity readings? 

No need to disconnect loads, I guess I'm mostly being ignored...
Charge controllers are a basically a voltage monitoring system, In their basic operation, they only step in to keep voltage from running too high or to time or measure current and turn off absorb and switch to a lower voltage to keep batteries from over charging.

Did you check your loads during the day? 
Did you check the solar array output during solar noon?

So long as your solar array can produce enough power to maintain voltage levels, you DO NOT need to turn off loads and don't need to run the generator.

What you are doing now is in an effort to save your batteries. That's great! but unless you had very ugly numbers in your settings;

fog said:

I can also see from the outback log that my system hasn’t floated or absorbed for 59 days.

This would indicate a 'broken' system or a system not sized to the loads.

Sounds like your settings were even lower than Rolls suggested. This would make it even easier to reach!
You need to figure out what is wrong. Did you add loads around the time of the watering? Was a major load added? Did a teenager come home? Was a desktop computer computer added? An old electric water heater have it's breaker flipped on (In fact if this is a previously grid tied home, perhaps other breakers turned off get flipped on?) 

Photowhit

mcgivor said:

The general concensus is to equalize with no loads so as to get to the target voltage then keeping it there without deviation, not really convenient,  but worth doing as it's it's generally a one or two times per year or less event,  assuming  the charging regime is keeping the SG readings at satisfactory levels.

Maintenance Equalizing should be done monthly on most systems, Particularly in tall case batteries.  My guess is with the sulfating caused by being less than 80% full for 2 months, it's going to be a long process to recover the batteries.


There is no need to disconnect the loads/inverter, unless the inverter isn't designed to handle the higher voltage. Or you can't reach the higher voltages.