weird battery problems with Rolls Surrette batteries, SG up to 1.30!

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  • maokmaok Registered Users Posts: 20
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    BB. wrote: »
    Do any of you guys have Battery Monitors (or equvalent) to measure the current and Amp*Hours you are running through the batteries during charging/loading?

    If you have parallel strings, is the wiring all equal length and tight connections? Have you used a DC amp meter to ensure that all strings are properly sharing the current?

    -Bill


    uupppsss,

    today I noticed, that my wirings isnt tight enough. when charging, it was big diference in the voltage on the charger /13,6V/ and on the batery terminals /13,18V/.

    so now I am charging, so we will see... thanks.
    ,
  • BB.BB. Super Moderators, Administrators Posts: 29,511 admin
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    maok wrote: »
    uupppsss,

    today I noticed, that my wirings isnt tight enough. when charging, it was big diference in the voltage on the charger /13,6V/ and on the batery terminals /13,18V/.

    so now I am charging, so we will see... thanks.
    Maok,

    That is still a pretty low voltage to be charging a battery bank with (unless, the bank is actually at a low state of charge and the battery charger is just pumping out its maximum amperage.

    Once the batteries become >80-90% charged--then you should see the current from the charger backing down (assuming the sun is still up/AC power still there) and getting towards 14.4 volts or so (not equalizing). You should see 13.2-13.8 from your charge controller only after the battery has been fully charged and is now "floating" with no loads.

    A good way to check the wiring/connections is to take your digital voltmeter and set it to 2 volt or 200mV scale and measure across each length of wire and each connection while the bank is under heavy charging or loading...

    Each point should all be similar voltage drop (probably much less than 0.1 volts). Any single point that reads differently (say you have two identical lengths of wire, One reads 0.024 volt drop and the other reads 0.103 volts drop). In this example, it could mean one of two things. Either the high voltage drop wire is bad (high resistance) or the high voltage drop wire is actually good (carrying lots of current() and there is something wrong in the other string because hardly any current is flowing trough that section of cable.

    I don't have a DC Current Clamp--but for debugging wiring/connections, I find that the DVM set to read small voltage drops is just about as useful (and a heck of a lot cheaper).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mbzebrombzebro Registered Users Posts: 18
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    hillbilly,
    I have good AC energy monitor (which also calculates daily consumption of connected appliances) and a DC current clamp.
    In my current installation I cant connect the AC monitor to the inverter output, I have to add it up myself.

    My calculation for my daily use this time of the year:
    I measured all my appliances at least once with AC monitor (or using current clamp).

    My fridge uses less than 400Wh per day (it stands cool): 16AH per day.
    Selfconsumption of my inverter plus the only always-on appliance, the wireless phone base draw 0.5A (current clamp): 12AH per day.
    600w waterpump, 30 minutes=300Wh per week, roughly 2AH per day.

    This adds to 30AH of base consumption (assuming 25V average battery voltage).

    4 bulbs on 7 hours a day 11 watts each: 280 Wh, 12AH.
    3 hours of notebook usage 40W: 120Wh, 5AH.
    Occasionally other appliances (mobile charger, drill etc), car radio: a few AH daily, say 5AH
    washing machine w/o heating every other day: less than 10AH per washing, 5AH per day

    sum: 57AH + 10% inverter loss = 63AH.

    Of course this varies from day to day, but should be a good average.

    When I had the problem with the S600 I checked this more than once because the battery voltages were so low, I went to my solar system shed at night with my current clamp and DVM to see if there are unexpectedly high discharge currents or voltage drops in the wiring. Everything was just how to be expected.

    The outback MX-60 also logs AH input; only considering the days where the batteries where charged full the day before it shows inputs from 60 to 120AH.
    This should confirm my calculations of daily use when you take into account that charge efficiency is probably well below 90% when doing 10% DOD cycles (typical on most days of the year), often with many hours of floating that add to AH input.

    Criteria for full charge:
    When I had my AGMs where no SG readings could be taken I used to judge full charge from charging current @ float voltage.
    This current started to rise with the age of my AGMs (700AH C10). In the end it never went below 4AH which I then took as fully charged. I also noted that after a week or two of deficit cycling the AGMs took a few days to recover to the low float current (light sulfation?).

    When I had the S-600 I did many EQs and often noted subsequent float (27.4V) currents of less than 2A. I am interpreting this as 99%+ full charge, well, as full as they could go.
    I cant say a lot about the 6CS17 yet, I just noted that even after a long EQ charging current never go below 10A @31V, so this also would indicate 99%+ SOC.

    I also write this all because I hope it shows that I did my homework before opening this thread.

    I am still awaiting response from my dealer, I will tell you when I know more.
  • mbzebrombzebro Registered Users Posts: 18
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    I just wanted to report the conversation I had with my dealer today.

    Most important: he will let me exchange the to batteries in question (before he had only offered to charge them).
    I also asked him to charge the replacement batteries in case they have an SG of less than 1.25, which he says he will do.
    It seems my little battery story will come to a happy ending!

    About charging the S-600 (my first set of batteries): he said they charged them for 3 or 4 days before they went up to nominal SG. I forgot to ask him about voltages, but I am pretty sure it was a standard bulk-absorb-float charge.

    He also said he is sure my two "bad "batteries, provided they are being cycled all the time, would become fine after some time, as good as the healthy ones, without taking additional measures.
    I said they should check SG and charge if necessary before selling them.
    He thinks this is not necessary at all, even after sitting many months the batteries would be fine after some time of cycling.

    From what I have learnt here this should be flat out wrong, the more time passes the more difficult it would be to desulfate them, and it would not happen at all by cycling them only.

    Any opinions?
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    gee, i thought the fla types were more forgiving and easier to deal with and the multiple threads showing up on surrettes seem to show a possible flaw in that thinking, at least for the surrettes anyway.
    are there any other fla types having this much trouble?
  • hillbillyhillbilly Solar Expert Posts: 334 ✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    niel wrote: »
    gee, i thought the fla types were more forgiving and easier to deal with and the multiple threads showing up on surrettes seem to show a possible flaw in that thinking, at least for the surrettes anyway.
    are there any other fla types having this much trouble?

    There is something to this. I've pondered for some time that it's kind of a double edged sword to have the ability to "really check" on the batteries via obsessing on SG levels, charging voltages, discharging voltages, amps in, amps out, average discharge, temperature.... etc. In many ways perhaps it's not so bad to have a tad less data to obsess on, and just keep plugging away until the batts fail.
    I've seriously considered going with a sealed battery to replace the current set of surrettes I have, not so much in the hopes that I'd have better luck with them as much as just the fact that I wouldn't be able to worry over them as much. To be fair, in my own case I think that the batteries have handled some abuse fairly well considering some of the lack of awareness I had when I first acquired them and how much use we've gotten so far from them. At this point in time some of the Concorde batteries are not all that much more than the Surrettes or Trojans now, of course I'm sure ALL batteries will go up some more in price right about the time that I absolutely NEED to replace mine.
    HB
  • mbzebrombzebro Registered Users Posts: 18
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    hillbilly wrote: »
    I've seriously considered going with a sealed battery to replace the current set of surrettes I have, not so much in the hopes that I'd have better luck with them as much as just the fact that I wouldn't be able to worry over them as much.
    You should not be too optimistic.

    When I bought the 2nd hand AGMs years agoI found it easy to be a bit obsessive and worried for a week or two, until I was confident all (24*2V) blocks were in a reasonable state and I had some feel for them.
    To get an idea about the state of indivual cells without SG readings I took loads of voltage readings of all cells at different charge/load currents and SOC. You get a lot of data to obsess and worry, believe me.

    With sealed batteries you can additionally worry about individual cells that go to high voltages on absorb (I had some going up to 2.60V), because they would lose electrolyte thru gasing and could eventually dry because you cant add water (which didnt happen).

    One thing I liked about my AGMs was low internal resistance and low peukert coefficient making them noticeably more efficient than my surrettes (are low peukert and low internal resistance necessarily linked?)

    Another advantage of AGMs is that being obsessive about them doesnt leave holes from sulfuric acid on clothes (my partner has found quite a few of them lately)
  • hillbillyhillbilly Solar Expert Posts: 334 ✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    mbzebro wrote: »
    To get an idea about the state of indivual cells without SG readings I took loads of voltage readings of all cells at different charge/load currents and SOC. You get a lot of data to obsess and worry, believe me.

    With sealed batteries you can additionally worry about individual cells that go to high voltages on absorb (I had some going up to 2.60V), because they would lose electrolyte thru gasing and could eventually dry because you cant add water (which didnt happen).

    One thing I liked about my AGMs was low internal resistance and low peukert coefficient making them noticeably more efficient than my surrettes (are low peukert and low internal resistance necessarily linked?)

    Another advantage of AGMs is that being obsessive about them doesnt leave holes from sulfuric acid on clothes (my partner has found quite a few of them lately)

    Yeah, I would probably find plenty to worry over anything that costs several thousand dollars and needs to last several years... the idea of "acid free obsessing" sounds a bit better though :-) My comment wasn't totally serious, except to point out that it can be possible to worry something to death, and in the case of batteries it's an easy trap to fall into I think. I wasn't really meaning to imply that you or anyone else's issues with FLA batteries were a simple result of over obsessing on them, but I think that it quite likely is an additional factor in general when dealing with batteries.
    Good luck on the new batteries!
    HB
  • mbzebrombzebro Registered Users Posts: 18
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    Yesterday I replaced my 2 surrette 6CS17. The new ones have date codes just 2 months from manufacturing and SGs of 1.27 in all cells (open circuit voltage 6.35), so I dont expect any issues this time.

    On self discharge and temperatures:

    yesterday I saw there were two 6CS17 remaining from the same pallet I had picked mine two months ago.
    They had not been charged in the mean time but had still SGs of 1.250 and higher (open circuit voltage 6.29) , so selfdischarge was minimal, in the 3% per month range.
    Even after 5 months (automn/winter) without charging there is probably no sulfation issue.
    So if not because of selfdischarge, why my 2 bad batteries were already discharged to 1.22 when they picked them from the same pallet? I can only suspect some additional problem or a charging error. I am happy I got rid of them.

    The S-600 I had issues with were (self)discharged to SG 1.23 within 4 (summer)months, something like 7% per month, so this was already too long because of the higher storage temperatures.
    To charge them from 50% to 100% SOC a 50A charger took 3 or 4 days. For a healthy battery 12 hours would have been more than sufficient, hard sulfation looks like the only explanation to me.


    My personal conclusion: I will never again buy a battery without seeing a SG of 1.25 or higher in all cells (for 1.265 nominal SG batteries) .
    Another conclusion: my dealer is a nice guy. He was letting me exchange batteries despite being convinced they would have "worked in" by themselves.
    Its a pity he does not tell his employees to check SGs before selling batteries. It would have been a lot less trouble for everybody.

    Again, thanks to all for helping and following this thread.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    Your dealer seems very good.

    It is relatively easy to get away with a voltage measurements with a small pocket DVM. It is much more difficult to find a supplier that will do or allow you to do an SG measurement.
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    I have been really disappointed with both the quality of the Surrette S530 batteries and their warranty (or lack thereof).

    I purchased a set of 8 Surrette S530 batteries in July 2008. Unfortunately, I did not check the date codes on them when I picked them up. I later discovered that the date codes were from September 2007 so the batteries had been in storage for 9 months prior.

    I spent many hours (>15) gathering data for their warranty process including many hours of equalization, numerous rounds of SG and voltage readings, and finally a load test (5 hours @ 37 amps). Though the SG's were all above 1.265 except for 2 cells (1.250 as I recall), my batteries provided only about 180 amp-hours prior to the voltage dropping to under 40V (for a 48V system). All of the batteries were at about 5.2V at the end of the test except 1 which was at 3.5V.

    Though all the batteries were at 5.2V at the end of the test, Surrette warranty said they would only replace the 1 battery that had dropped to 3.5V, claiming that single battery had somehow compromised the capacity of the other batteries. I pointed out that even if the 3.5V battery were 5.2V, the whole string would still be well under 42V which is their definition of a full state of discharge. At 180 ah, the capacity of the other batteries was well below their spec of 400 ah (20 hours rate, so it would be a bit less at 37A which is roughly the 10 hour rate).

    I'm going to see if the local distributor I picked up the batteries from will replace them. I'm an EE with access to test equipment so I could easily determine when they were dispensing the happy horseshit. But, I could only imagine the confusion they would sow with a layperson along with the endless time one would expend trying to get them to honor their warranty.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    http://www.dcbattery.com/rollssurrette_s530.pdf

    37 amps, is closer to the 8 hour rate, fully charged ( 1.265 SP GR ) is speced for 320ah. Was your SP GR made at 25C? if not you have to compensate for temperature.

    What did you use for a load? only an electronic load tester could provide constant current, a load through an inverter would be constant power and as the voltage drops the current would increase.

    Having weak cells will effect the test, make charging full near impossible and on discharge when the cell become near dead will drop not proportional to the remaining cells capacity
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    tennyson wrote: »
    Though all the batteries were at 5.2V at the end of the test, Surrette warranty said they would only replace the 1 battery that had dropped to 3.5V, claiming that single battery had somehow compromised the capacity of the other batteries. I pointed out that even if the 3.5V battery were 5.2V, the whole string would still be well under 42V which is their definition of a full state of discharge. At 180 ah, the capacity of the other batteries was well below their spec of 400 ah (20 hours rate, so it would be a bit less at 37A which is roughly the 10 hour rate).

    I'm going to see if the local distributor I picked up the batteries from will replace them. I'm an EE with access to test equipment so I could easily determine when they were dispensing the happy horseshit. But, I could only imagine the confusion they would sow with a layperson along with the endless time one would expend trying to get them to honor their warranty.

    I have had similar experience years ago, albeit with a different brand. That one battery can go bad and cause damage to the others isn't BS. That they should use that as an excuse to not warrant all affected batteries in a single application is.

    In my case it was three in series on a 36 Volt (yes) system. Two went bad, and the dealer wouldn't replace them saying they were properly charged. The fact that this is impossible in a series install didn't sway him. I've never bought anything from them again, and have recommended to everyone around here to stay far clear of them.

    This is why I regard warranties as an unreliable measure of a product's quality; you can warrant anything for anything, but if no one stands behind it a warranty is just a piece of paper full of words made up by weasily lawyers to absolve the manufacturer/retailer of any responsibility. I prefer to rely on the real-world experiences people have had, which includes the results of what happens if they screw up - an important 'acid test' of both product and seller.

    So does Surrette make good batteries? Or just expensive ones? Might as well buy from Costco, after hearing the positive responses from those who have!
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    trkarl wrote: »
    I called Surrette again and had a long conversation with a tech named Serge. His email is [email protected]. He was very helpful. I found that the date codes on the three batteries were different than the other ones. But it was only off by about 8 months so no big deal. He said that they were probably dry stored and then activated when i ordered them. He said that to dry store them they fill them with electrolyte and fully charge them then remove the electrolyte and wash them out and maybe not all the acid was washed off the plates on those batteries with the high sg. That is what I was told.

    Meant to comment on this earlier,

    Eight month separation on manf. date on a new batch of batteries I was installing is greater then I would want to see.

    Once a battery has had positive plates formed and electrolyte installed it is important that the plates are always covered with either normal electrolyte or distilled water. Exposing plates to air for much time is a no-no, just like the case where electrolyte level has dropped below top of plates. The air exposed plates will sulfate quickly. In the case of exposed top of plate, when water is finally added, it comes under a super high charge rate from the lower unexposed plates. This can warp the top section of plates, possibly causing them to crush separator and short out.

    A battery can be drained of its electrolyte for storage (after it has been fully recharged) but must be replaced with distilled water covering the plates for storage. To re-activate, drain water and replace electrolyte.

    True dry charge batteries, thoughs without fully formed positive plates and electrolyte saturated separator, will develope some lead dioxide coating on both positive and negative plates from oxygen in the air. This is not damaging and the negative plate will shed the lead dioxide shortly after being discharged and charged a few times.
  • mbzebrombzebro Registered Users Posts: 18
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    I have seen the recommendation many times that stored wet lead acid batteries and even AGMs should be full charged at least every 3 months. I have also read that sulfation resulting from long storage without recharge is considered being of the ugly kind.
    Obviously many local distributors dont follow this recommendation at the risk of selling already damaged or hard sulfated batteries.

    What my string of 4 Surrette 6CS17 concerns, both older and replacement batteries are doing very well.
    In these days (a lot of excess power) I read a low charge current @float voltage of around 1.0 A every afternoon, SGs of all cells are about 1.28.
    I guess the low float current is indicating healthy batteries being near 100% charged.

    Interesting observation: in the beginning I followed closely (a bit suspiciously after my experiences) the behaviour of my battery string.
    I noted an difference between the 2 original and the 2 replacement blocks, especially in the first few weeks.

    - during charge, the older batteries had significantly higher voltages per block, often 0.2V and more per 6V block.
    - there was almost no difference between the blocks of same age (0.02V or less per block)
    - there was almost no difference (0.02V or less) between older and newer blocks on discharge, even at high rate.
    - the higher the SOC, the bigger the difference in voltage between old and new blocks grew on charge.

    I found the difference to be surprisingly high.
    To avoid a permanent strong gassing of the older pair (and the new pair having a too low charge voltage) I applied a 12V load of 5A exclusively on the older 2 blocks for an hour or so to equalize the suspected difference of SOC, which worked.
    I was surprised to see the same difference again the next day. I applied a load again and saw it happen again the other day.

    My explanation: Surrette says new batteries have only about 75% of the rated capacity and take 2-3 months of cycling to reach 100% (RCinFLA has explained why in his earlier post).

    The new blocks were gaining capacity with every cycle; while the old blocks were almost full and their internal resistance was raising, the new blocks could take a few AH more after every discharge and consequently had a lower internal resistance, so the same charge current was leading to considerably different cell voltages on higher SOCs.

    Is this a commonly known phenomenon when combining new batteries with older ones?

    I would appreciate any comment on this, just curious if my explanation is correct.
    (I am happy with my surrettes now and dont suspect any new battery issue, also in the meantime the differences have become a lot smaller).
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    I have had similar experience years ago, albeit with a different brand. That one battery can go bad and cause damage to the others isn't BS. That they should use that as an excuse to not warrant all affected batteries in a single application is.

    In my case it was three in series on a 36 Volt (yes) system. Two went bad, and the dealer wouldn't replace them saying they were properly charged. The fact that this is impossible in a series install didn't sway him. I've never bought anything from them again, and have recommended to everyone around here to stay far clear of them.

    In the circumstance where a battery connected in series exhibits an unusually low voltage during charging, I could see that causing overvoltage on the other batteries in the string. But, this would be evidenced by excessively high voltage during charging on the other batteries in the string which I did not see.

    It is undesirable to use batteries that are not well matched in capacity in a string because the batteries with higher capacity can reverse bias the weaker cells when they are fully discharged. But, this did not happen in my case either.
    This is why I regard warranties as an unreliable measure of a product's quality; you can warrant anything for anything, but if no one stands behind it a warranty is just a piece of paper full of words made up by weasily lawyers to absolve the manufacturer/retailer of any responsibility. I prefer to rely on the real-world experiences people have had, which includes the results of what happens if they screw up - an important 'acid test' of both product and seller.

    So does Surrette make good batteries? Or just expensive ones? Might as well buy from Costco, after hearing the positive responses from those who have!

    My major mistake was not to check the battery date codes before taking delivery of the batteries. Unless their distributor steps up to honor the warranty, I will have to go after them in small claims.

    I can't vouch for the quality of their batteries, but I know from experience that Costco at least honors their warranties. (I have a set of their GC2 golf cart batteries that is still in good shape after 2 years of daily cycling--separate 24v system.)
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    http://www.dcbattery.com/rollssurrette_s530.pdf

    37 amps, is closer to the 8 hour rate, fully charged ( 1.265 SP GR ) is speced for 320ah. Was your SP GR made at 25C? if not you have to compensate for temperature.

    All the cells were equalized and at or above 1.265 SG except for 2 cells which would not go above 1.250 after extended equalization. Temperature was between 20 and 25C when measured. Interestingly, the battery that dropped to 3.5V during the load test was not one of the batteries with a 1.250 SG cell.
    What did you use for a load? only an electronic load tester could provide constant current, a load through an inverter would be constant power and as the voltage drops the current would increase.

    The load was a powerware 9125 inverter with a 1500 watt space heater as the load. I am aware the current drawn from the batteries would increase somewhat as the battery voltage declined. The average current was 37 amps (range +/-10% as battery voltage dropped). The amp-hours discharged as measured by the Apollo T80 charge controller was within a percent of the total calculated from the data sampled with my data logger (records voltage & current every second during the test).
    Having weak cells will effect the test, make charging full near impossible and on discharge when the cell become near dead will drop not proportional to the remaining cells capacity

    During charging and equalization, the 8 batteries stayed within a few tenths of a volt of each other.

    At the end of the load test, the voltage on 7 of the batteries was 5.2V +/-0.2V which is 100% depth-of-discharge as defined by Surrette. This was after only delivering 183 amp-hours. The 8th battery which was at 3.5V at the end of the load test had no significant effect on the test since the other 7 batteries had already reached full discharge.


    Excerpts of the emails I sent to Serge @ Surrette:

    Prior to the load test, I equalized the cells and the SG readings were as follows before the load test:

    Battery 1: 1.275, 1.275, 1.270
    Battery 2: 1.270, 1.270, 1.270
    Battery 3: 1.270, 1.270, 1.270
    Battery 4: 1.275, 1.275, 1.255
    Battery 5: 1.270, 1.265, 1.250
    Battery 6: 1.280, 1.270, 1.270
    Battery 7: 1.270, 1.275, 1.265
    Battery 8: 1.275, 1.270, 1.265


    I load tested the batteries they provided only 183 amp-hours prior to the voltage dropping under 40V. This was with a 37 amp load (inverter running a 1500 watt space heater). Attached are photos of the charge controller displaying the battery capacity before and at the end of the test. I checked the battery voltages at the end of the test and found that one battery was a couple volts lower than the rest, but all the batteries had substantially lower voltages than would be expected for properly functioning batteries at 54% state of charge (less than half depleted).

    > The voltages and SG readings at the end of the load test were:
    >
    > Battery 1: 5.35V, 1.150, 1.165, 1.155
    > Battery 2: 5.25V, 1.125, 1.125, 1.125
    > Battery 3: 5.21V, 1.140, 1.130, 1.130
    > Battery 4: 5.26V, 1.150, 1.135, 1.140
    > Battery 5: 5.14V, 1.145, 1.135, 1.150
    > Battery 6: 5.19V, 1.150, 1.150, 1.130
    > Battery 7: 5.08V, 1.130, 1.140, 1.125
    > Battery 8: 3.48V, 1.135, 1.150, 1.125
    >
    > The load was a Powerware 9125 inverter powering a 1500 watt space heater.
    >
    > The duration of the test was about 5 hours. The test ended when the inverter shut down from low input voltage around 40V.
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    One other curious thing I noticed on Surrette's S530 datasheet:

    DESIGN CRITREA[sic] 7 YEAR WARRANTY 1300 CYCLES 10 YEAR LIFE

    How does 1300 cycles correlate with either 7 or 10 years? The length of the year is relatively constant at 365 days. So 7x365 is 2555 or 10x365 is 3650...unless one assumes the sun only rises every other day... (or the 1300 cycles is for 100% depth-of-discharge? but this is not specified in their datasheet)
  • mbzebrombzebro Registered Users Posts: 18
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    There are charts of DOD vs cycle life where you can see that Surrette is referring to 50% DOD cycles. When only discharging to 10% or 20% DOD daily, many more cycles can be expected (approximately linear to 50% DOD/real DOD ratio), according to these charts.

    One thing I just noted is that Surrette replaced the spec sheets of the S4000 series. Where before capacity was given for 1.265 SG now I see only 1.280 SG; the capacity should be 5% higher for the 1.280 SG, but it reads the same.
    When I searched for spec sheets for the 6CS17 I found older ones with 1.265 and newer ones with 1.280 SG, with other specifications like capacity being equal.

    The labels of me 6CS17 all say 1.265 SG, but all my cells show 1.280-1.290 SG.
    If they changed electrolyte SG from 1.265 to 1.280 they should tell their customers.
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    mbzebro wrote: »
    There are charts of DOD vs cycle life where you can see that Surrette is referring to 50% DOD cycles. When only discharging to 10% or 20% DOD daily, many more cycles can be expected (approximately linear to 50% DOD/real DOD ratio), according to these charts.

    One thing I just noted is that Surrette replaced the spec sheets of the S4000 series. Where before capacity was given for 1.265 SG now I see only 1.280 SG; the capacity should be 5% higher for the 1.280 SG, but it reads the same.
    When I searched for spec sheets for the 6CS17 I found older ones with 1.265 and newer ones with 1.280 SG, with other specifications like capacity being equal.

    The labels of me 6CS17 all say 1.265 SG, but all my cells show 1.280-1.290 SG.
    If they changed electrolyte SG from 1.265 to 1.280 they should tell their customers.

    If it's 1300 50% DOD cycles, it seems dubious to scale that to 2655 (their 7 year pro-rated warranty) or 3650 cycles (10 year "design" life).


    In my S530's of late 2007 vintage, I was never able to get the SG above 1.280 and even that only occurred in a few cells after extended equalization.

    After my experience with trying to get Surrette to replace clearly substandard (<50% rated capacity) batteries after only 1.5 years and when it was clearly documented those cells had been in storage for 9 months prior to my receiving them, I would question the value of their warranty.

    I can only imagine the excuses they will present. From my discussions with Serge @ Surrette, it seems they expect people to continually take SG and individual battery voltage readings at least every few weeks. And they will arbitrarily claim some parameter was improper to avoid honoring their warranty. For instance, the absorb time should be 6 hours instead of 2, the absorb voltage should be 59.5V instead of 58.5V, the equalization voltage should be 64.2V instead of 62.4V, and so forth. In a twisted way, I was actually impressed by the creativity in their dissembling. It reminded me so much of a certain house builder (and their subcontractors) whose motto seemed to be "delay and obfuscate".
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    http://www.dcbattery.com/rollssurrette_s530.pdf

    37 amps, is closer to the 8 hour rate, fully charged ( 1.265 SP GR ) is speced for 320ah. Was your SP GR made at 25C? if not you have to compensate for temperature.

    I forgot to mention. I didn't come up with the 37 amp load arbitrarily. I wanted to run the load test at the 20 hour rate. But, Serge @ Surrette insisted it had to be done at 35 amps. So, I did the best I could to oblige.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    There is a 20% difference in amps pulling at 40V vs 48V ... so that would probably push you close to 45 amps towards the end of the test. Inverters for this reason are not a good method to verify ah capacity. Looking at the chart, you would be closer to 300ah , not 400ah you posted

    I also would be some what suspect on the accuracy of the T80, for sure its not going to report within 1%, if your going to challenge the manufacture, you should probably use a 50amp , 100mv shunt and a DVM ( voltage across the shunt ) to verify the current draw, I'm assuming your using a 500amp/50mv shunt which is 5% typical shunt tolerance and further effect your ah calculations.

    Hopefully, when you get the two bad cells replaced, you will get much closer to expected performance.
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    There is a 20% difference in amps pulling at 40V vs 48V ... so that would probably push you close to 45 amps towards the end of the test. Inverters for this reason are not a good method to verify ah capacity. Looking at the chart, you would be closer to 300ah , not 400ah you posted


    I don't have a electronic simulation device that can handle 2 kw loads. That is an expensive instrument that would cost more than these batteries did.

    As I recall, the current varied from about 33 A to 41 A with the average at 37 A. If you wanted to nitpick, the ending voltage for the 8 battery (48V nominal) string would be 42V and not 40V. I selected 40V because that is the low voltage shutdown point of the inverter. With a 42V cutoff, the capacity would be even lower than the measured 183 ah.

    In addition to the amp-hour metering on the Apollo T80 charge controller, I have voltage and and current measured and recorded every second during the test. Both were in agreement within 1%. No matter how you interpret it, 183 ah is not even close to 340 ah or even 300 ah.
    I also would be some what suspect on the accuracy of the T80, for sure its not going to report within 1%, if your going to challenge the manufacture, you should probably use a 50amp , 100mv shunt and a DVM ( voltage across the shunt ) to verify the current draw, I'm assuming your using a 500amp/50mv shunt which is 5% typical shunt tolerance and further effect your ah calculations.

    My system uses a 50mv/500A shunt. The Apollo T80 uses that for its current sensing and for the data logger recording. I also used extech and fluke clamp-on ammeters to verify the accuracy. The fluke clamp-on ammeter provides a DC voltage output proportional to current which was also recorded. I have very high confidence in the acquired data because measurements from multiple instruments were in agreement.

    But, this is really moot as the 183 Ah is half the rated capacity, not 90% or 95%.
    Hopefully, when you get the two bad cells replaced, you will get much closer to expected performance.

    Surrette only offered to replace 1 battery of the 8 which would be a futile exercise. Replacing that single battery would provide negligible improvement in the overall performance of the string as the load test data showed the other 7 batteries were at about 5.2V at the end of the load test which indicates they were 100% discharged as well.

    I'm curious as to your motivations. Are you a Surrette dealer? I have no interest in this other than to inform others so they don't fall into the same trap I did. The moral of the story is to check the battery date codes and reject any batteries that are more than about 3 months old and more closely scrutinize any that are more than 1 month old.
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    I'm assuming your using a 500amp/50mv shunt which is 5% typical shunt tolerance and further effect your ah calculations.

    A 5% typical accuracy current shunt? In over 20 years in the electronics industry, I've never even come across one with that poor an accuracy. Of course, proper techniques need to be used to compensate for any thermocouple effect offset to achieve high accuracy.

    My shunt is 0.25% rated accuracy and cost about $25 as I recall.

    http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2949204&k=500A%20shunt

    http://www.murata-ps.com/data/meters/dpm_shunts.pdf

    http://store.kta-ev.com/deltecshunt500a50mv.aspx
  • trkarltrkarl Solar Expert Posts: 33
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    RCinFLA wrote: »
    Meant to comment on this earlier,

    Eight month separation on manf. date on a new batch of batteries I was installing is greater then I would want to see.

    RC you are right. The surrette site says that their dry stored batteries have a shelf life of five years and if stored longer will just take longer to activate with no ill effects. That is why I wrote no big deal especially on batteries that are supposed to have a life of around 15 years or more.

    I should have did my homework and specified that all batteries have the same date and an extremely recent one as well but I didn't. So far they have performed extremely well after a year of service but I am not hard on them either.

    My main problem with their quality control was the huge disparity of sg between the cells which should not have been there especially if they were all activated at the same time and same place in the same way. For a supposed superior battery manufacturer this seemed way out of whack.

    I also noticed that now the specs on their site in pdf now rate them with a sg of 1.280 when before they were rated with an sg of 1.265 .
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    trkarl wrote: »
    RC you are right. The surrette site says that their dry stored batteries have a shelf life of five years and if stored longer will just take longer to activate with no ill effects. That is why I wrote no big deal especially on batteries that are supposed to have a life of around 15 years or more.

    I should have did my homework and specified that all batteries have the same date and an extremely recent one as well but I didn't. So far they have performed extremely well after a year of service but I am not hard on them either.

    My main problem with their quality control was the huge disparity of sg between the cells which should not have been there especially if they were all activated at the same time and same place in the same way. For a supposed superior battery manufacturer this seemed way out of whack.

    I also noticed that now the specs on their site in pdf now rate them with a sg of 1.280 when before they were rated with an sg of 1.265 .

    I would imagine lead plates exposed to air will form lead oxide which is insoluble in water. As I recall, lead oxide is even less soluble than lead sulfate which causes the problems of lost capacity in batteries stored not fully charged for a long time. The areas of the plate covered with an insoluble material because inactive, thus reducing battery capacity, and probably deforming the plate over time too.

    I was not hard on my set of 8 S530's either. My average daily depth-of-discharge was only about 25% as it was used principally to run network and computer gear which draws a relatively constant 5 amps. According to Surrette's specs, the S530 batteries should have provided 530 ah at the 100 hour (5 A) rate.

    What are the absorb settings you are all using? I used the defaults stored in the Apollo T80 charge controller. It had a specific "rolls" selection for surrette S530s which was 58.2V for 2 hours for absorb and 62.4V for 2 hours for equalization. (I had it set to equalize every 60 days.)

    I'm starting to regret that I didn't take a chance on some chinese made 260 Ah lithium iron phosphate (LiFePo4) cells instead of lead acid.
  • jeffkrusejeffkruse Solar Expert Posts: 205 ✭✭✭
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    I have my absorb time set to max (8hours). I never get 8 hours of absorb and when I do get a long absorb day the voltage and current in the late afternoon is less (but still more than float).
  • trkarltrkarl Solar Expert Posts: 33
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!

    As far as the absorb v and time goes reading the different bulletins at the surrette site will give you different answers. I also talked to different rolls techs and each gave me a different answer.

    I started out with the voltage set at 58.6 and absorb at 3 hrs but quickly found it was not enough. Over the course of a couple months I would test the sg of a couple cells each day sometimes at different times during the absorb cycle. If left at that setting the sg would steadily drop daily by a small amount.

    Then I raised the voltage to 59.2 and went to 4 hours. Then I added more panels and now have it set at 58v and 6 hrs. It hardly ever gets to 6 hrs though. You just have to watch the water consumption and sg and you will get a feel for when they are at about 95+ % charged and whether or not you are overcharging them.

    Also if I have several days of clouds on a sunny day right after that I will raise the voltage to make up for the deficit of the cloudy days. If several sunny days in a row I will prematurely float them instead of going through a complete absorb cycle but this is after taking an sg reading and comparing it to records.

    I like taking a big hands on approach to my battery bank. I think why a lot of people ruin there batteries is because they think this is just a set it and forget it type of thing which I think is a big mistake. It's not like plugging in a dvd player. Each different site has different weather and temperature to deal with. All this has an effect on how the batteries charge and how deep they are discharged.

    All this though is just relating my experience with my batteries and in no way should be taken as how you should maintain yours. You will have to decide that.
  • tennysontennyson Registered Users Posts: 10
    Re: weird battery problems with Rolls Surrette batteries, SG up to 1.30!
    trkarl wrote: »
    As far as the absorb v and time goes reading the different bulletins at the surrette site will give you different answers. I also talked to different rolls techs and each gave me a different answer.

    I started out with the voltage set at 58.6 and absorb at 3 hrs but quickly found it was not enough. Over the course of a couple months I would test the sg of a couple cells each day sometimes at different times during the absorb cycle. If left at that setting the sg would steadily drop daily by a small amount.

    Then I raised the voltage to 59.2 and went to 4 hours. Then I added more panels and now have it set at 58v and 6 hrs. It hardly ever gets to 6 hrs though. You just have to watch the water consumption and sg and you will get a feel for when they are at about 95+ % charged and whether or not you are overcharging them.

    Also if I have several days of clouds on a sunny day right after that I will raise the voltage to make up for the deficit of the cloudy days. If several sunny days in a row I will prematurely float them instead of going through a complete absorb cycle but this is after taking an sg reading and comparing it to records.

    I like taking a big hands on approach to my battery bank. I think why a lot of people ruin there batteries is because they think this is just a set it and forget it type of thing which I think is a big mistake. It's not like plugging in a dvd player. Each different site has different weather and temperature to deal with. All this has an effect on how the batteries charge and how deep they are discharged.

    All this though is just relating my experience with my batteries and in no way should be taken as how you should maintain yours. You will have to decide that.

    That is quite interesting. I have a lot of experience with sealed (VRLA and other type: both AGM and gel), but have only used flooded non-sealed cells a few times before and those were smaller systems.

    From what I found on the web, it appears that the Surrette chemistry is harder to bring to full charge than batteries from other manufacturers and requires a substantially longer absorb time and/or higher voltage. I purchased the batteries and charge controller from the same dealer (thesolarbiz.com) and they did not mention it this at all and just said to use the settings in the Apollo T80 charge controller which had a specific setting for Rolls(Surrette) 400Ah batteries. The distributor I picked up the batteries from also did not mention it or supply any documentation with the batteries.

    I'm starting to think lithium iron phosphate (LiFePo4) cells would have been a better though more expensive choice.

    LiFePo4 cells are now available in up to 500 amp-hour sized cells. (up from 260 Ah the last time I looked about 1.5 years ago) The quality is unknown and I imagine the warranty would be no easier to enforce than with Surrette. On the other hand, it's hard to imagine how much worse the warranty response could be compared to my experience with Surrette.

    As an electronics engineer for the past 2 decades, I am saddened that these leading edge products are only available from China.

    http://optimum-china.en.made-in-china.com/product/uMmJOpbcCWhX/China-3-2v-Lifepo4-Battery-400ah.html

    http://upbattery.en.made-in-china.com/product/CMlQUGsPnIVd/China-LIFEPO4-3-2V-320V-4AH-500AH.html
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