I don't really like my Surrettes

YehoshuaAgapao

No failed batteries yet, but still seem to be at about 50% of the capacity that I should be getting, which is better than before but still not as advertised. 2 strings of Surrette S-530 L-16s (Original 12 megapixel size)

Load shaved for about 3 hours, about 6KW-h at 40-50 amps (800AH). Measured SGs in the center cell on 5 batteries in the right box and measured the voltages in all the batteries in the right box and they are a bit under 70% state of charge - 3 SGs were 1.215 (measuring 1.210 but temperature corrector says add 0.006), though 2 were higher closer to 1.220. Single battery voltages were 6.17 to 6.19 volts with 5 of them at 6.18 (Trojan has good state of charge chart). Full capacity should be 38.4 KW-h. But i'm 1/3 discharged. Fully charged SGs are running between 1.260 and 1.265. The battery bank has about 20 cycles on them right now, 17 for load shaving during the month of may and 3 when I ran the system off-grid prior to commissioning during February. The real sucky thing about these Surretes and they ran down to 47.9V under load and when load shave ends they bounce up to 49.45V when the load ends. And its consistent with this chart (bottom of page) for voltage under load (C/20 assumed; I was between C/15 and C/20). That is a pretty high internal resistance...

These are my current charge settings: Float - 52.5 (manual specification), Bulk: 59.4 (high), Absorb: 58.8 (high), EQ: 64.0 (flooded default). I raised bulk to 59.4 because I don't think it is staying in absorption long enough. Bulk is higher than absorption makes it run at the higher voltage for one hour with no early exit (current at 2% of programmed AH capacity). Now I am getting a good 90 minutes of absorption when it was previously exiting in less than an hour. These are being adjusted down 0.2-0.5V for temperature. I am using enhanced interactive mode and the inverter keeps grid support at the controller set points during absorption and 1 volt below during float. By 9AM the solar panels are putting out about 60-65 amps. I'm thinking about changing the programmed AH capacity to 400AH (it is realy 800) to encourage more absorption time. These Surrettes easily absorb to less than AH/100 (8A). I last EQd the batteries in the first week of may by setting Absorption to 64 volts over that weekend (Xantrex's automatic EQ only runs for 1 hour). That got all the cells right to 1.265. SGs won't go over 1.265. I thought they do batteries at 1.280?

stephendv

Re: I don't really like my Surrettes

That 2% rating to end absorb is a bit too soon in my opinion. Here's a graph of the charge going into my forklift batts. The 2% mark is where the dot is.

Attachment not found.

As you can see they keep accepting a charge for almost 2 hours after the 2% mark is reached. If you can, you could increase absorb for at least an hour or two longer than what it is now and then check the SGs. With summer on the way, it would be easier on the batteries to have them in absorb for longer, rather than push the absorb voltage higher.

Blackcherry04

Re: I don't really like my Surrettes

YehoshuaAgapao wrote: »

That got all the cells right to 1.265. SGs won't go over 1.265. I thought they do batteries at 1.280?

I don't think they changed to 1.280 until March of this year. Anything prior to that would still be 1.265.

ChrisOlson

Re: I don't really like my Surrettes

The correct SG for those is the same as ours - 1.265-1.270. They are typical Surrette's, though, and the absorb time is probably too short. So you need to either bump the absorb voltage up to 2.58 VPC, or lengthen the absorb time to 4 hours. Or even more ideal use a high voltage constant-current finish stage, which all of Surrette's charging recommendations are based on anyway.

Surrette was supposed to be hiring a guy to adapt the industrial charger recommendations that are published in all their paperwork to the type used in RE that don't have a finish stage. But I never heard anything more about it, and that was over a year ago. Many people make the mistake of applying the absorb recommendation for a IUIa industrial constant-current charger (which is what is used in Surrette's charging specs) to RE chargers that don't have a finish stage. The result is sulfated batteries, lost capacity, and shortened battery life.
--
Chris

Cariboocoot

Re: I don't really like my Surrettes

Ignore manufacturer's info and charts. Their Volt meters, hydrometers, thermometers, and usage aren't the same as yours and sometimes the info they give out is just plain wrong.

Charge batteries fully when brand new; even "overcharge" them. Let sit overnight. Check Voltage and SG with your instruments then. This establishes a baseline to work from. If you have an SG above about 1.260 and consistent across all cells chances are the batteries are fine, no matter what numbers you've been given.

I'm not keen on Surrette anymore either, as there have been issues with new batteries & customer service. Couple that with the 'normal' operating Voltages (higher than some RE equipment is designed to work with) and in my opinion they are just not worth the money.

NorthGuy

Re: I don't really like my Surrettes

Based on Surrette's chart 1.22 corresponds to 75%. If you took 6kWh (7kWh from batteries counting all inefficiencies), this put capacity roughly to 28kWh. The Surrete's web page that you've linked says at the bottom that you're going to get 75% of rated capacity at the beginning. That's about what you've got.

The voltage sug under relatively small load is a little bit too big - 1.5V. But that could be cables as well. If you have a voltmeter that measures in mV (or better), you can measure voltage drop on every interconnecting cable end every connection. Perhaps you find a voltage drop somewhere. Cables may be faulty. Connections may not be tightened enough, may be dirty, corrioded etc. It's worth looking at.

Peple who have S-530 can tell you what kind of voltage drop they get under similar load.

Joe_B

Re: I don't really like my Surrettes

Stevendv is right, 2% is a problem. You can fool the XW by telling it that the bank is half the size and then it will run to 1%. Also, I set my float voltage to the same as my absorb voltage so that the bank gets "overcharged" because I typically lose solar behind the trees and my harvest drops for about 2 hours before sunset. During those two hours, the bank will get topped off. if I dropped the float voltage, to spec. I never get to 100% except on the sunniest of days.

BTW, I have Trojans with the 1.260 SG and they have been performing nicely for four years. Before this bank I had a bunch of T105's and they lasted over 10 years before I sold them to a guy who is still using them. I have read a lot of bad stuff about Surrette's on this forum.

Vic

Re: I don't really like my Surrettes

All of the Surrette Solar batteries that I know of are STILL shipping with 1.265 SG electrolyte. They are speced at 1.280 SG, but not shipped this way.

Trojan, on the other hand, HAS changed the SG as shipped, and not changed the model number of the RE-B batteries, IIRC.

So, the actual Capacity for S-530s at the 20 Hr rate is 380 AH nominal -- a 5% reduction. 760 AH for a string of two.

All of the Surrette banks here need a finishing current of 1.00% of actual 20 Hr C (reduced by five percent of speced 20 hr C).

The 64 V EQ is at the very high end of the recommended range.

Agree with Stephen, that if one has the time available to extend the Abs time, this is preferable to raising the Vabs.

Also, cycling the bank to about 50% SOC should be good for the batteries. Surrettes do like to be worked hard, at least on occasion.

One good measure of how well FLAs are being charged is the amount of water consumption. How much water do these S-530s need/how often?

Am still very happy with the Surrette banks here, and those of friends and neighbors seem to be holding up very well, too. Eight years of off-grid service here ... knock knock ...
Opinions, Vic

ChrisOlson

Re: I don't really like my Surrettes

All the "bad" things that people post about Surrette's are mostly about losing capacity, or not having normal capacity, or cells with low SG. And every time I read about absorb voltages that are below 2.45 VPC and/or absorb times that are woefully short. Without the voltage being up there they won't draw any amps and on chargers with Ending Amps they'll exit the absorb stage early.

The S-530's are 4000-series, just like ours. And I don't care what anybody says, you can't absorb those batteries properly at 2.45 VPC in only 2-3 hours. You'll end up with batteries that go "limp" after awhile.
--
Chris

stephendv

Re: I don't really like my Surrettes

ChrisOlson wrote: »

And I don't care what anybody says, you can't absorb those batteries properly at 2.45 VPC in only 2-3 hours. You'll end up with batteries that go "limp" after awhile.

That depends on the depth of discharge surely. A battery that was only discharged 10% the previous night would surely absorb fine in 3 hours, no?
Have you tried increasing your absorb time and reducing the absorb voltage now that there's enough sun to keep them in absorb for a decent amount of time?

Cariboocoot

Re: I don't really like my Surrettes

If the Absorb Voltage isn't at the right level there really isn't an Absorb stage: it's just held in Voltage-limited Bulk for a long time. Something like taking them to 80% SOC and keeping them there for a few hours, then letting it fall off again. Eventually it becomes a problem just as Chris said.

YehoshuaAgapao

Re: I don't really like my Surrettes

All of the Surrette banks here need a finishing current of 1.00% of actual 20 Hr C (reduced by five percent of speced 20 hr C).

I'll change AH capacity to 300 to get it absorbing for the full time. I'll try lowering the voltage because I'm sure the high voltage (58.8 absorb, 59.4 bulk / 1hr boost charge) is shortening my battery life. These batteries have absorbed down to as low as 6 amps in the past (lower voltage - less amps, very short absorb time).

One good measure of how well FLAs are being charged is the amount of water consumption. How much water do these S-530s need/how often?

Water consumption is pretty low (I think). I last watered the day before EQing in the beginning of May and took about 1/2 gallon of water to top off from previous watering about 6 weeks before then. It takes at least 60V to get the occasional audible bubble glurp in the batteries, 64V to get audible fizzing.

YehoshuaAgapao

Re: I don't really like my Surrettes

ChrisOlson wrote: »

The correct SG for those is the same as ours - 1.265-1.270. They are typical Surrette's, though, and the absorb time is probably too short. So you need to either bump the absorb voltage up to 2.58 VPC, or lengthen the absorb time to 4 hours. Or even more ideal use a high voltage constant-current finish stage, which all of Surrette's charging recommendations are based on anyway.
Chris

Xantrex exits absorption at 2% of programmed AH capacity. It seems from the replies combined with the formulas from surrete manual coming out to 3.5-6 hours of absorption time (depending on bulk current) I should lower the programmed AH capacity to not just 400 but to 300AH as I observed these batteries absorbing to 6A. The only side effect is that during EQ, current will be limited to 10% of programmed AH capacity, but Xantrex's built-in EQ sucks (EQs for only 1 hour, fixed, cannot change) and I think EQ works better by Absorbing to 64V. There is lots of sun, and I am only cycling for load shaving (shifting actually) and non-cycling funks out the SG cell-balance in these batteries. Maybe setting the AH to 300 will allow these batteries to hold SG at 57.6V absorption? Right now need 58.8 to hold SG wit non-cycling and is insufficient when cycling (which is why I raised bulk to 59.4 for a 1 hour 'boost' charge).

YehoshuaAgapao

Re: I don't really like my Surrettes

Blackcherry04 wrote: »

I don't think they changed to 1.280 until March of this year. Anything prior to that would still be 1.265.

That is good to know. I was told by sales person they are charged bey default to 1.280 when 1.250 or 1.265 is not requested by customer. The batteries were purchased September 2012, placed in maint charging November 2012 (could only operate generator, or grid-bypass at the time; panels went up Dec 2012 when all approvals came in - panels small portion of total install work) and placed in full service February 2013 (grid tie commision).

I got the surretes because I got them for $288 each, plus $600 for shipping (drop-ship from Surrette) for all 16 of them. Before that I was thinking of a much smaller bank of 16 Trojan T-105RE but that great $288 price its hard to not accept the sale & up-sell.

YehoshuaAgapao

Re: I don't really like my Surrettes

ChrisOlson wrote: »

All the "bad" things that people post about Surrette's are mostly about losing capacity, or not having normal capacity, or cells with low SG. And every time I read about absorb voltages that are below 2.45 VPC and/or absorb times that are woefully short. Without the voltage being up there they won't draw any amps and on chargers with Ending Amps they'll exit the absorb stage early.

The S-530's are 4000-series, just like ours. And I don't care what anybody says, you can't absorb those batteries properly at 2.45 VPC in only 2-3 hours. You'll end up with batteries that go "limp" after awhile.
--
Chris

My batteries do not hold SGs at 57.6V as the manual says. They do hold at 58.8, but after 3 weeks of load shaving I was noticing capacity loss (the time it takes to get down to 48.5V) and very fast absorption exits, but things started stabilizing when raising bulk voltage to 59.4V (leaving absorption at 58.8, which makes it run 59.4 for 1 hour then drop to 58.8 for rest of abosrption). From the advice from the other replies i'm going to set AH capacity to not 400 but 300 as I observed these surrettes absorbing down to 6A (at 58.8V, lower, 4-5A at 57.6). I will try reducing bulk to 58.8 and absorb to 57.6 as aggressive voltages shortens battery life (though sulfation kills batteries too). Its AZ, there is plenty of sun for long-term solar powered absorption charges.

ChrisOlson

Re: I don't really like my Surrettes

Of course, yes, I'm assuming discharging to 50% SOC. Ever since I had problems with the batteries when new (low SG and low capacity) I have never reduced the absorb voltage from what Surrette recommended (2.58VPC). They are a tall-case battery and the electrolyte does not get mixed good enough at lower absorb. We cycle our batteries from 50-80% for sometimes up to 10 days, and when the day comes that they get absorbed they need the higher voltage or they will lose capacity over several cycles and require a EQ to bring it back.

If they were getting fully absorbed every day, then I think the voltage could maybe be lowered some. But I have also read about a lot of Surrette owners having problems with that program too. So I don't do it.
--
Chris

petertearai

Re: I don't really like my Surrettes

Hi my surrettes are 1280, and were from new 2 and a bit years ago. All going well . When first installed I set end amps to 5amps.( this was determined from having absorb set to forever and watching for the flat point. Now set to 6amps and 3 hour absorb. My situation is different from yous as typically they are used in weekends and then sit for a week or 2 before next going up to the holiday house. On arival the fm80 stats report usually only a few minutes absorb, while in residence the absorb will often go the full 3 hours. Anyway good batterys as far as I can tell.

waynefromnscanada

Re: I don't really like my Surrettes

petertearai wrote: »

Hi my surrettes are 1280, and were from new 2 and a bit years ago. All going well . When first installed I set end amps to 5amps.( this was determined from having absorb set to forever and watching for the flat point. Now set to 6amps and 3 hour absorb. My situation is different from yous as typically they are used in weekends and then sit for a week or 2 before next going up to the holiday house. On arival the fm80 stats report usually only a few minutes absorb, while in residence the absorb will often go the full 3 hours. Anyway good batterys as far as I can tell.

Very good to hear something positive re Surrette as my next set are likely to be 2 volt (L-16) Surrettes unless something changes. Good info. Thanks for sharing.

Cariboocoot

Re: I don't really like my Surrettes

Keep in mind the Surrettes you buy in New Zealand are not necessarily the same as the ones you buy in the USA or Canada. The reported problems with some of the new ones may be the result of a QC failure at a particular plant.

Batteries: always a gamble to some extent. :roll:

ChrisOlson

Re: I don't really like my Surrettes

YehoshuaAgapao wrote: »

My batteries do not hold SGs at 57.6V as the manual says. They do hold at 58.8, but after 3 weeks of load shaving I was noticing capacity loss (the time it takes to get down to 48.5V) and very fast absorption exits, but things started stabilizing when raising bulk voltage to 59.4V (leaving absorption at 58.8, which makes it run 59.4 for 1 hour then drop to 58.8 for rest of abosrption).

Gosh, I dunno - I would leave the amp-hour capacity at what they actually are if they were mine. I see no reason to fiddle with that. You have seen the benefit of using the higher absorb voltage by using the XW's boost charge feature.

I have many months of data from the logging in my Classics that show that using 2.58 VPC absorb for 2.5 hours yield cooler running batteries than using 2.45 VPC for 4 hours. There were many days when our absorb only gets to 2.45 VPC because of loads. The controller stays in Bulk MPPT mode instead of going to absorb because the voltage never goes high enough. And some days they'll hang there, with the voltage bouncing around depending on the loads, for 6-8 hours. The batteries never do reach fully charged SG when that happens (whenever I have checked), but they do get several degrees warmer than on a "good" day when the loads aren't there so they can go thru a normal absorb at 62.0V.

When I discovered this while reviewing my logged data I adjusted the voltage offset for the Waste Not Hi so it doesn't do that. I loaded the system earlier to keep the voltage down while the water heating loads are on to prevent the battery temp from going up so high. When the water heaters get caught up then the voltage jumps right up to 62.0 and hopefully there's enough power left to get the 2.5 hour absorb done. Sometimes there is, sometimes there isn't. But the batteries definitely run cooler by doing that.

So that's my 2 cents on it. Don't be afraid to bump that absorb voltage up. It works. Monitor it with the hydrometer the first few cycles by sampling some random cells to see how long it takes at the higher voltage and program your controllers to absorb for that length of time, based on your SG samples, and how long it takes to get them to 1.265 (1.250-1.255 will be more normal in hot weather). Leave the amp-hours at actual so if you do happen to get several "good" days where the batteries get short-cycled (not below 70-80% SOC) that you don't over-do it and use too much water.
--
Chris

YehoshuaAgapao

Re: I don't really like my Surrettes

ChrisOlson wrote: »

Gosh, I dunno - I would leave the amp-hour capacity at what they actually are if they were mine. I see no reason to fiddle with that. You have seen the benefit of using the higher absorb voltage by using the XW's boost charge feature.

I have many months of data from the logging in my Classics that show that using 2.58 VPC absorb for 2.5 hours yield cooler running batteries than using 2.45 VPC for 4 hours. There were many days when our absorb only gets to 2.45 VPC because of loads. The controller stays in Bulk MPPT mode instead of going to absorb because the voltage never goes high enough. And some days they'll hang there, with the voltage bouncing around depending on the loads, for 6-8 hours. The batteries never do reach fully charged SG when that happens (whenever I have checked), but they do get several degrees warmer than on a "good" day when the loads aren't there so they can go thru a normal absorb at 62.0V.

When I discovered this while reviewing my logged data I adjusted the voltage offset for the Waste Not Hi so it doesn't do that. I loaded the system earlier to keep the voltage down while the water heating loads are on to prevent the battery temp from going up so high. When the water heaters get caught up then the voltage jumps right up to 62.0 and hopefully there's enough power left to get the 2.5 hour absorb done. Sometimes there is, sometimes there isn't. But the batteries definitely run cooler by doing that.

So that's my 2 cents on it. Don't be afraid to bump that absorb voltage up. It works. Monitor it with the hydrometer the first few cycles by sampling some random cells to see how long it takes at the higher voltage and program your controllers to absorb for that length of time, based on your SG samples, and how long it takes to get them to 1.265 (1.250-1.255 will be more normal in hot weather). Leave the amp-hours at actual so if you do happen to get several "good" days where the batteries get short-cycled (not below 70-80% SOC) that you don't over-do it and use too much water.
--
Chris

I've read that excessive voltage causes extra plate shedding (reduced battery life). The higher voltage does work, and pretty well but I want to try for the longer absorb time at lower voltage to see if it works also. There is lots of sun here in AZ. I have overkill ventilation in my battery boxes so internal heat gets sucked out pretty effectively. There is a swamp cooler blowing into the house at the garage entrance so the garge is getting secondary cooling and the battery temps are running about 29C even though it is 100-105F outside.

I did change some settings to this effect:

Old settings: Bulk 59.4V, Absorb, 58.8V, Float 52.5V, MaxAbsorb 240 min, AmpHourCapacity: 800 (Absorb exit at 16A; Max EQ 80A)
New settings: Bulk 58.8V, Absorb, 57.6V, Float 52.5V, MaxAbsorb 360 min, AmpHourCapacity: 300 (Absorb exit at 6A; Max EQ 30A)

If the SGs don't hold I will change the absorb back to 58.8.
Bulk higher than absorb is effective for the first 60 minutes of absorption with no current-based exit (2% of AmpHourCapacity).

I will watch to see if there are any other side effects of the reduced AH capacity setting but the manual documents it as impacting absorption exit current and Max EQ current (which I hate the built-in EQ support - its only 1 hour).


I have 3 4'x8' flat plate solar water heating collectors (AET DX-96-120). Water heating is only 1.25 amps for me. The backup element is currently disconnected. It rarely needs to be connected and only in winter. The backup element is also not on the inverter load subpanel (no 220V circuit is). It is a drainback system. Drainback systems can be safely oversized and they handle freeze quite well also.

ChrisOlson

Re: I don't really like my Surrettes

YehoshuaAgapao wrote: »

I've read that excessive voltage causes extra plate shedding (reduced battery life).

Shedding of the active plate material is a normal process in the aging of a battery. Heat kills batteries too, and I've read where every so many degrees over 77 cuts the battery's life in half (I think it's something like 10 degrees F). I've also read studies done on forklift batteries that indicated that grid erosion does not kill most of them - sulfation does.

When you charge the sulfate on the plates goes back into solution in the electrolyte. You will not get excessive shedding of the plate material unless you over-do it. The hydrometer tells the story. If you absorb at higher voltage for only the length of time it takes to get the SG up to spec, that means all the sulfate has gone back into solution and it's time to end the absorb cycle. If you absorb for a longer time at lower voltage and all the sulfate does not go back into solution you are well on your way to having reduced capacity and batteries that will only be recovered by what Surrette calls "corrective equalization" at ridiculous voltages to remove the hard sulfate from the plates.

The corrective EQ is a smelly, messy process and I went thru 3-4 weeks of it when my batteries were almost new because the voltages Surrette publishes in the manual for the 4000-series are bogus. I'm anal about monitoring my batteries and I became very alarmed when they were new because they did not have the "zip" they should've had and the SG was not getting up to spec during absorb. So I called Surrette and told them about it, and that I was not happy about it. They told me to increase the absorb to 2.58 VPC. The process I had to go thru to get brand new batteries up to what they should be "out of the box" was not something that I would wish on anybody. And I suspect that 95% of battery owners would've never caught it before it was too late, with the result that 2 years down the road you got batteries that are hard sulfated and on their way to dying of the cancerous disease.

Which is harder on the battery? Batteries are just like people - they're all going to die eventually. Are they going to die from old age after a normal life, or some cancerous disease? Either way, when that time comes, they're done. I've read about a lot more Surrette's (and Trojans and what have you) dying from the cancerous disease than from old age.

You are already noting loss of capacity, based on your original post. That's exactly what I had, at about the same age as your batteries are. And the same series of batteries with the same plates. Search thru the forum here on the problems people have had with Surrettes and you will find that it is a common theme. And you will find that the people that have successfully "fixed" it did it with higher absorb voltages.

One of our other forum members here - NorthGuy - has some industrial Trojans that also exhibited this problem, but to an even greater extent than the Surrettes do. After reading about what he has to go thru to get his batteries charged, I wouldn't wish that on anybody either. But unlike what Surrette did for me, Trojan told him that he's stuck with it, have a good day - see ya' around.

It seems that 90% of the time, when somebody who is actually monitoring their batteries notes a problem that doesn't seem normal, when they call tech support you get somebody that got their support credentials off a Cheerios boxtop and they only know how to read what it says in their support materials. They know actually very little about batteries. But sometimes you get somebody that actually knows what's going on, and is interested in making the customer happy with their purchase instead of selling batteries. The manufacturer is not the one that wins when a customer buys batteries and they last 10 years. They want to sell you a new set in 5 years.

IMHO.
--
Chris

BB.

Re: I don't really like my Surrettes

The engineering rule of thumb is 1/2 life for every 10C increase in temperature (and 2x life for every 10C decrease).

I would guess that the batteries are "hurt" with lots of fizzing... As long as there is not much fiz when charging (even at higher voltages), you probably are not doing significant damage to the batteries (at least when compared with sulfation issues). Once the battery is charged, having them fiz for longer periods of time (more than 1/2 to 1 hour a couple times a week) is probably not helpful.

-Bill

Cariboocoot

Re: I don't really like my Surrettes

The problem is that "fizzing" is subjective: one man's fizz is another man's bubbling nicely.

In general you can crank up Absorb Voltage until you get issues with excess water loss (difficult to determine at the time it's happening) and internal heating. Therein lies the problem: you have to raise the Voltage point and then use them a while to see if they work better. If so, increase it some more and wait another month. No improvement? Turn it back down. This kind of fine-tuning is ore art than science and yet another reason to buy the cheap batteries first; no one wants to fry expensive ones.

If the Voltage level of Absorb didn't matter we could just set it and Float to battery resting Voltage point and it would all work fine. But it does so we can't and it wouldn't.

Steve Higgins

Re: I don't really like my Surrettes

Hello All,

My name is Steve Higgins and I'm the Technical Services Manager at Rolls. I'm sorry to hear about all the problems and want to help out the best I can.

First off, one of my challenges that I have here at Surrette is the manual isn't very clear and the mixing of the AGM with the Flooded cells sometimes makes it difficult for customers to understand. Doing a rewrite/reorganization of this manual is on my to do list, unfortunately this list is pretty long at this time.

As mentioned in the posts already, a big issue with Surrette based systems is the lack of charging voltage. These batteries are an industrial type battery with a very large plate design, this requires a substantially higher charge voltage to keep the SG's where they need to be which ranges depending on temperature can range from 1.255 to 1.280.

Our Absorb Set point without temperature compensation is between 2.4 and 2.5vpc. With temp compensation set to the 5mv/Deg/Cell you should have your Absorb/Bulk Voltage set to at least 2.45vpc.

The Absorb time is also imperative, with a single XW6048 and an 800 ah battery bank you are looking at a absorb time of at least 2.6-3 Hours.

Another issue that battery manufactures face is distribution, getting the cells to the customers quickly so installations can be done quickly. This requires distribution to stock batteries and not all of them are properly boost charging those cells while in the warehouse. Normally a Flooded cell battery depending on temp can lose 8-12% of its capacity... so if your batteries were manufactured 3 months ago and you install them today there is a good chance they are going to be 25%-35% down when you receive them. This is why it's imperative that you charge them manually to a full state before use.

What I would do for this system:

Since the XW is a bit finicky I would set your bulk/absorb to 58.8... and an absorb time of at least 3 hours under the custom setting screen.

I'm not too familiar with the Xantrex battery monitor, but what I would do is at least once (preferably 3-4) per week do a heavier bulk/absorb by setting your float (Temporally) to 59.2 to 59.4 volts for at least a 3-4 hour time frame.

I would always have your controllers set to at least 59.2 to 59.6... this number would vary depending on how much sun you are getting, and where your SG's are sitting.

You can do EQ's but i'm not a big fan of them unless you are seeing large discrepancies in SG between cells. If all your cells are in a general .01 to .020 and EQ isn't really necessary. Another issue with the XW is that inverter limits you to a 1 hour time.. you can bypass this by tricking it by setting the float up to the EQ voltage for a time frame.

The batteries only have about 20 cycles on them, Surrette Cells normally take about 60-90 cycles to come to a full cycle potential. I would start hitting them with the higher charge voltages for the next 30-45 days and you should see an improvement in capacity.

my direct email is s t e v e@surrette.com (no spaces in steve to keep the spammers away) feel free to contact me anytime. I can't always monitor these forums so please either email me direct, or give me some time for a response.

Thanks.

ChrisOlson

Re: I don't really like my Surrettes

The tall case ones need to fizz good because if they don't the electrolyte ends up as water at the top and dense 1.300 stuff at the bottom, and will give you abnormally low SG readings. With our T12-250's it takes at least 2 hours of fizzing or bubbling to get it mixed up decent, and I think they're about the same length plates as the L-16 (S530) type. Although I think the S530's have a little more sump area than the T12's, but the T12's have more reserve over the top of the plates.

Our Surrette's don't use hardly any water in the winter. In the summer they'll take 5 gallons about every three months because they tend to get absorbed more. One of the upsides to higher Absorb voltage is that I've never had to do a maintenance EQ in last year and a half. Every single cell is so dead even on SG that they have never needed it since I bumped absorb to 2.58 VPC. And the capacity is awesome. They'll hold a 4-5 kW load (20 amps per battery) on the inverter for up to three hours, just on battery power, without sagging below 48.0V at the inverter power studs. Two years and three months old.
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Chris

waynefromnscanada

Re: I don't really like my Surrettes

Good info provided by Steve from Surrette. Thanks man!

Cariboocoot

Re: I don't really like my Surrettes

Welcome to the forum Steve.

I must say you're joining is a ray of sunshine on a metaphorical and literal rainy day. You do not know how long we've wanted some direct input from battery makers around here. It's been "reverse engineering" for years on our part, and trying to "black box" a battery is pretty much hopeless!

ChrisOlson

Re: I don't really like my Surrettes

Steve Higgins wrote: »

I'm not too familiar with the Xantrex battery monitor, but what I would do is at least once (preferably 3-4) per week do a heavier bulk/absorb by setting your float (Temporally) to 59.2 to 59.4 volts for at least a 3-4 hour time frame.

Steve - I think you're the same guy I talked to at Surrette two years ago that was working on re-writing those manuals

I'd like to point out that some controllers (like my Classic 150's) won't let you set the Float stage higher than Absorb so you can use it for a finish stage. But I think the XW controllers (and inverter) will let a person do that. When we talked we arrived at the conclusion that our system don't spend a lot of time in Float anyway, and barely makes Absorb once a week or so. So that's why we went with the 2.58 VPC absorb for 2.5 hours to get them where they should be on SG.

It has worked VERY well here, and totally happy with our batteries after we got them up to spec when new.
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Chris

Steve Higgins

Re: I don't really like my Surrettes

Thanks for the warm welcome, I have to be honest, sometimes these things turn bad.

I came on with Surrette about 9 months ago, The last twenty years I've been working for primarily inverter companies, so I'll be honest it's taken me some time to get my legs underneath me as it comes to batteries.

I've been lurking for the last few months, Again I will do what ever I can to to help anytime.

Regards.

ChrisOlson

Re: I don't really like my Surrettes

Steve Higgins wrote: »

I came on with Surrette about 9 months ago

Hmmm.... You must not be who I talked to a couple years ago then. But whoever it was said they were working on re-writing those manuals, or it was on the back burner to do. You must be the guy that inherited the job :cool:
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Chris