I don't really like my Surrettes

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Comments

  • Steve HigginsSteve Higgins Registered Users Posts: 13 ✭✭
    Re: I don't really like my Surrettes

    Chris, I only started at Surrette back in Sept of last year. Yea... It was me who Inherited it along with putting together a training program for them.

    As for your system, I think you are doing the right thing, the hardest part to make people understand is that EVERYONE's System is different because every system is different because the end users have different lifestyles.

    My favorite quote is " I've installed this same system in 5 houses and this one house I keep having problems with." Most often a couple of tweaks to the system and you can make it work.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: I don't really like my Surrettes
    As for your system, I think you are doing the right thing, the hardest part to make people understand is that EVERYONE's System is different because every system is different because the end users have different lifestyles.

    My favorite quote is " I've installed this same system in 5 houses and this one house I keep having problems with." Most often a couple of tweaks to the system and you can make it work.

    Boy oh boy oh boy oh boy!
    How many times have we reiterated that each and every install is different even if they are "the same"? But does anyone listen? :p

    Sorry to hear you got stuck with the ugly re-write task.
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    As for your system, I think you are doing the right thing, the hardest part to make people understand is that EVERYONE's System is different because every system is different because the end users have different lifestyles.

    Yep. We bought our batteries from a dealer only 50 miles SW of us that has been handling Surrette traction and locomotive batteries for over 25 years. The dealer, and your tech support, was excellent in helping us get our new batteries up to spec and keeping them that way. I was a little scared at first when we had problems with them after spending $9,000 on them. But after we got that sorted out they have been totally trouble free, other than adding water.
    --
    Chris
  • BB.BB. Super Moderators, Administrators Posts: 29,482 admin
    Re: I don't really like my Surrettes

    Thank you Steve for joining the forum. We will try to be on our best behavior here (we always try for a professional/family friendly feel around here).

    Much of the problem here with batteries is we have variable loads and variable/limited charging energy available (i.e., solar panels that get sun for 2-8 hours per day depending on season and weather conditions).

    Much of the battery lititure seems to be written for industrial applications where there is always a virtually unlimited energy source (power and time) available (grid, generators, etc.) to follow the "ideal" charging cycle.

    Also, another issue seems to be that some battery models/construction need fairly "stiff" charging voltages and the "typical" AC inverter mfg. will fault at those higher voltages (typically the mass market cutoff seems to be ~15-16 volts or 60-62 volts for a 48 volt bank).

    Knowing more about the batteries (chemistry/construction) would help guide people to an appropriate choice for their installations.

    And a "workable" charging scheme that favors long and happy battery life.

    We (I) from reading of people's experiences here (and some mfg. information) seem to have come up with a set of rules that should work. And it would be nice to know if we are on the right track or not.

    One set of rules is avoid deep cycling (below 50% of battery capacity) to get longer life. And recharge back >90% state of charge a couple times a week. Some vendors recommend equalization when specific gravity varies by ~0.015 to 0.030 or more points, and others say to "equalize" every month or two (or do both) with ~2.5-5% current (we use 20 hour capacity for sanity for all rules of thumbs).

    A very interesting method to get good battery life and more efficient energy use would be to cycle the batteries between 80% to 50% state of charge (daily/over a couple days) and only recharge back >90% between every 5 to 10 days. Sulfation should not be a big issue with this usage as the lead sulfate is being "cycled" daily. We have a couple folks here that do that sort of cycling (Chris Olson, Stephenv) and at least one European Charge Controller mfg. (Victron or was it SMA) that supports "delayed" full recharging for a few days if batteries are not deeply cycled.

    Another rule of thumb is 5-13% rate of charge: 5% minimum (no other loads during charging on the DC power system). 10% is a healthy nominal rate of charge. And 13% is maximum rate of charge without active thermal management--i.e., remote battery temperature sensor. It is possible to recharge upwards of 20-25% rate of charge, but that should be with "normal" charging voltage set points and those size of currents for batteries at 80% state of charge or less (battery should taper current to well less than 20% as it approaches full charge).

    Recommend not to "store" lead acid batteries below ~75% state of charge ever.

    Otherwise, the usual that we do not recommend "over equalization of batteries" (supply equalization current until all cells stop rising in SG after 30-60 minutes between readings) or stop if batteries get too hot. Don't equalize (gas) batteries too often. And don't take batteries to near dead (below 20% state of charge--which is still hard on battery life anyway).

    For flooded cell batteries, we have been recommending increasing absorb time and charging voltages and monitoring battery health with a good quality hydrometer (typically glass float) with temperature compensation for SG readings.

    Anyway, lots of questions--Some of which you may not be able to answer--But anything you can help us with would be greatly appreciated.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: I don't really like my Surrettes
    Hello All,

    My name is Steve Higgins and I'm the Technical Services Manager at Rolls.

    Hi Steve,

    Welcome to the forum. Its good to see you here... You have always been a great resource over at the Outback forums (and I see that you still do post there).

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    BB. wrote: »
    We have a couple folks here that do that sort of cycling (Chris Olson, Stephenv) and at least one European Charge Controller mfg. (Victron or was it SMA) that supports "delayed" full recharging for a few days if batteries are not deeply cycled.

    Actually, that's one of the things I wish the Classic controller would do. On the times when we get our batteries to Float stage, the wind power many times holds them there and they don't need to be re-bulked until the voltage drops to the re-bulk level. But the Classic resets at midnight and starts a new "day", setting the charge stage back to Bulk MPPT. So it absorbs the batteries again when they don't need it. I have reset the clocks in my controllers so they roll over before bedtime and I have to manually force them back to Float stage when the turbines are running, after they roll over.
    --
    Chris
  • BB.BB. Super Moderators, Administrators Posts: 29,482 admin
    Re: I don't really like my Surrettes

    Hmm... Sounds almost like a bug. Most (high end) controllers would not start a bulk/absorb cycle until the battery voltage falls below ~12.7 volts for at least a few minutes.

    Is there a "rebulk" or equivalent setting in the Midnite?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    BB. wrote: »
    Is there a "rebulk" or equivalent setting in the Midnite?

    Yep. And I have that set at 48.0 with the assumption that it would not re-bulk and absorb the bank again until the voltage (either loaded or at rest) gets to that point. But it doesn't work unless the voltage drops that low on the same day. At midnight when the Classic rolls its logs over it resets the charge stage back to Bulk MPPT and does a full bulk/absorb again, even if the batteries don't need it.
    --
    Chris
  • Ralph DayRalph Day Solar Expert Posts: 886 ✭✭✭✭
    Re: I don't really like my Surrettes

    Our MX60 does the same Chris. I believe there's a 25 hour clock so that even if the wind has held us at or above float level overnight it will attempt a full charge next "day". Easy enough to trip to float again, but if you're not around there's an unneeded charge cycle done. I find that end amps is not a viable charge stop method either, when wind is in the mix. The loads might be low, the sun and wind contributing, then the solar component can drop out or at least below the end amps level and the mx60 cycle drops to float when it should still be absorbing. Any hints?

    \Ralph
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    Ralph Day wrote: »
    I find that end amps is not a viable charge stop method either, when wind is in the mix. The loads might be low, the sun and wind contributing, then the solar component can drop out or at least below the end amps level and the mx60 cycle drops to float when it should still be absorbing. Any hints?

    No hints. It's the same here with wind power thrown into the mix, and End Amps simply doesn't work. MidNite Solar is working on a shunt-based outfit that will tell the controllers exactly how much is going to the batteries so End Amps works properly. But I haven't seen it yet. I hope the shunt is big enough to handle big inverters because all the inverter DC power is going to have to go thru that shunt too, so the controller "sees" a net amount of charging amps actually going to the batteries to make it's decision on whether to end Absorb.
    --
    Chris
  • Steve HigginsSteve Higgins Registered Users Posts: 13 ✭✭
    Re: I don't really like my Surrettes

    I don't want to get too much off the original thread, but here goes.

    Yes, I am the Steve that was once at Outback, and I pretty much troll the forums actively looking for Surrette battery issues. It's going to be a long process, but I want to make the Surrette support team the best in the industry.

    The optimum for most lead acid batteries is 50-80% cycling. As long as the flooded cells see a full 100% state at least once per month.

    As for charge current rates the max is usually about 30-35% it really depends on the chemistry and plate construction of the cell. Rates over this while the bulk stage can cause excessive heating and warping of the plates. It will also cause shedding, or if done excessively will cause the positive plate to turn into a sponge.

    Good charge rates are about 10-15% this is not for battery health but in an off grid system if you less than 10% charge capacity to the battery bank, charging that bank can feel much trying to fill up a swimming pool with a gallon bucket! This current directly affects how long the absorb cycle should be... Many customers just outright refuse to run their gensets for a full absorb cycle, that's fine if they have the solar, or renewable to make up for it, but often the customers have way too big of a battery bank and this just ends up speeding up the sulfation process.

    I usually recommend if you are going to spend 8-20K on a battery bank, spend the 100-200 on a good quality refractometer.. many are temp compensated at this range and much easier to use than a Hydrometer. You also don't get the cross contamination issues you would see with a Hydrometer. Extech Make and RF41 that's pretty reasonable.
  • BB.BB. Super Moderators, Administrators Posts: 29,482 admin
    Re: I don't really like my Surrettes

    I think this is the Refactometer that Steve is referring to:

    http://www.extech.com/instruments/product.asp?catid=17&prodid=508

    ~$90 from Amazon.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    The optimum for most lead acid batteries is 50-80% cycling. As long as the flooded cells see a full 100% state at least once per month.

    That's what our Surrette battery dealer told us, but he said to bring them all the way up once every week to 10 days. In the winter a few times we have gone up to two weeks without a full absorb and it didn't seem to hurt them at all. At least, the reason I thought it didn't seem to hurt them is because when they finally got charged up I checked a few random cells and they came up to 1.255-1.260 with just a normal absorb cycle.

    So I have the aux ports in my controllers set to load the system with water heating loads, specifically to prevent fully charging the batteries more than once a week. It had taken a lot of fiddling to make it work, but my feeling is that it reduces the number of discharge/charge cycles that the batteries "see" over a period of time. For us it has worked well - our batteries test out very healthy yet, with full rated capacity, at 2.25 years old.
    --
    Chris
  • YehoshuaAgapaoYehoshuaAgapao Solar Expert Posts: 280 ✭✭
    Re: I don't really like my Surrettes
    Doing a rewrite/reorganization of this manual is on my to do list, unfortunately this list is pretty long at this time.

    The manual is in bad need of revision. The manual and this forum often in disagreement and the forum is right most of the 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.

    It ran this morning with 58.8 bulk 57.6 Absorb (Bulk higher than absorb runs the bulk voltage for 1 hour with no current-based exit). It exited Absorption at 8:45 AM this morning about. Solar starts meaningful production about 6:30AM right now.
    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.

    Getting extended absorption time with Xantrex and Surrette together seems be kind of difficult. Xantrex exits absorption at 2% of the amp-hour setting in amps (16A for 800AH).
    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.

    I was told these batteries were drop-shipped directly from Surrette and the Pallets had a Canadian sender address. I got the batteries in September 2012. They got wired up to the inverter November 2012 and been on a maintenance charge off the generator every two weeks until December 2012. Then they were under true charge maintenance until February 2013 when the grid-tie was commissioned and the batteries got their first 3 cycles (with very poor capacity) they weekend before commissioning when I rant he system off-grid for the thrill of it and to make sure everything works. The SGs were low until about March when I got the hydrometer to find out and followed Chris's insane voltage advice for a week (Didn't go all the way to 60V though, but did 59.4 absorption, but temperature corrected at the time and it was over 60V) which got the SGs back up and then I tapered down the voltage a bit, back to default 57.6 at first but then the SGs started dropping and then put to 58.8, which stabilized the SG fall. All maintenance charging from November 2012 to March 2013 were on default flooded battery settings - 57.6V bulk/absorb, 54.5V float, 64V equalize.
    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'll put the voltages back the way I had them but leave AH capacity at 300 (absorbtion exit 6A). That was 59.4V Bulk 58.8V Absorb. At 58.8V Bulk 57.6V Absorb 300AH capacity, absorption exited at 8:45AM (about 3hr 15min total charging time on about 3 hours of load shaving, about 6KWh).
    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.

    Would using the 59.4V bulk boost charge feature while lying on the AH capacity work just as well? Well I'll try it. I think I want to see it absorbing at least to after I leave for work around 10AM (4+ hours of total charging time on about 6KWh of discharge + losses).

    Plenty of sun here in AZ. And I am grid-tied also (Have a bi-modal system ready for California-style blackouts whenever the dollar does implode, and load-shaving summer on-peak hours until then), so unlike the true off-gridders in the northern climates, I have plenty of charging. I do try to charge solar only though.

    Why the insane voltages? I was reading chronic voltages this high are destructive to batteries, though such batteries are assumed to be AGM or standard deep cycle flooded batteries. Series 4000 compares more with Crown/Trojan RE batteries (Favor Trojan); 5000 series compares more with the Crown Forklift and Trojan Industrial batteries (Favor Crown).
    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.

    I did only 1 EQ in the beginning of May. These batteries don't like being not cycled. SGs become very uneven (0.01 or more). The EQ in may evened them up and got nearly every batter to a textbook 1.265 (assuming these are charged to 1.265, but was told by sales person default was 1.280 but SGs won't go over 1.265). In march I used the insane absorption voltage to get the SGs up. I did the EQ by doing a 64 volt absorption charge. It is the only 4 hour absorption charge Xantrex has ever delivered.
    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.

    I expect to put about 125 cycles a year on the batteries to about 25-25% DOD (Well should be anyway, turning out to be 35%). Load shave 1PM-8PM (all but 2.5-4 hours covered by solar) summer on-peak 5 days per week May-August (May/June to buld up credits, July/August on Air conditioner; Sept/Oct back on swamp cooler & don't need to hoard on-peak net-metering credits; winter on-peak not worth using cycles on batteries at all; SRP cashes out credits at wholesale at end of April) and load shave 1 day per week at other times (cycle excerise).

    As far as cycle warmup, I think I should be getting about 70% capacity? -25% for being new betteries, -5% for being charged to 1.265 instead of 1.280. They seem charged to 1.265, people in this thread say 1.265, but salesperson says 1.280 is default when 1.265 or 1.250 is not requested, so my batteries may still be sulfated isntead? I have never seen a SG rating over 1.265 in these batteries. I seem to be getting 50% capacity instead of 70% though (draw 6-7 KWH brings down to 65% SOC is about half capacity).
    my direct email is s t e v [email protected] (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.

    I got one other question. Is a 1.5V drop between open circuit and 36-50 amp load (18-25 amps each string and cable set; each string has separate 4/0 cable to DC busbars in PDP) excessive, even for surrette? Surrette have terrible internal resistance (ratio between C/20 and C/5 capacities vs Crown and Trojan) so it might be normal for surrette batteries? I'll copy and paste to your email also, but I think this will be good knowledge to share especially with everyone treating you like a minor celebrity in the thread.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: I don't really like my Surrettes
    I don't want to get too much off the original thread, but here goes.

    Yes, I am the Steve that was once at Outback, and I pretty much troll the forums actively looking for Surrette battery issues. It's going to be a long process, but I want to make the Surrette support team the best in the industry.

    The optimum for most lead acid batteries is 50-80% cycling. As long as the flooded cells see a full 100% state at least once per month.

    As for charge current rates the max is usually about 30-35% it really depends on the chemistry and plate construction of the cell. Rates over this while the bulk stage can cause excessive heating and warping of the plates. It will also cause shedding, or if done excessively will cause the positive plate to turn into a sponge.

    Hi Steve and thanks for showing your head. :-)
    And best fortune (hope you don't need luck) in building the Support structure and credibility.

    So far your advice has concentrated on pure PV charging and what can be done with it.
    But many of the members follow the advice that batteries without a generator for occasional maintenance is a difficult spot to be in.
    For those who have generators and chargers to go with them (either in their inverter/chargers or standalone), do you have some advice there?
    I do see that you mentioned generators in your latest post, but only in passing.
    The consensus here so far seems to be to use the generator to bulk the batteries in the morning when needed to allow the whole solar day to be usable for absorb and/or finish instead of trying to keep the generator running wastefully for low amps. But that is only valid advice if your day is long enough for the PV to give the Absorb the batts need.
    Also not to try to Eq the bank on PV alone.
    Can you elaborate on generator use, with specific reference to the Surrettes? Would you favor going near the 30% rate when bulking with the generator to reduce running time, or to treat the batteries more gently and hold it down to 15%, for example?
    SMA SB 3000, old BP panels.
  • YehoshuaAgapaoYehoshuaAgapao Solar Expert Posts: 280 ✭✭
    Re: I don't really like my Surrettes
    I don't want to get too much off the original thread, but here goes.

    Yes, I am the Steve that was once at Outback, and I pretty much troll the forums actively looking for Surrette battery issues. It's going to be a long process, but I want to make the Surrette support team the best in the industry.

    I don't perceive a good customer service reputation in the forums for Surrette. That's why I never bothered to talk to Surrette tech support. People say your techs always reply 'corrective EQ' as it was some magic cure-all.
    The optimum for most lead acid batteries is 50-80% cycling. As long as the flooded cells see a full 100% state at least once per month.

    Think the Surrette cycle life charts favor 70% DOD while most generic charts are 60% DOD (Multiplying DOD by cycle life number) while Trojan RE is 30% or 40%.
    As for charge current rates the max is usually about 30-35% it really depends on the chemistry and plate construction of the cell. Rates over this while the bulk stage can cause excessive heating and warping of the plates. It will also cause shedding, or if done excessively will cause the positive plate to turn into a sponge.

    Good charge rates are about 10-15% this is not for battery health but in an off grid system if you less than 10% charge capacity to the battery bank, charging that bank can feel much trying to fill up a swimming pool with a gallon bucket! This current directly affects how long the absorb cycle should be... Many customers just outright refuse to run their gensets for a full absorb cycle, that's fine if they have the solar, or renewable to make up for it, but often the customers have way too big of a battery bank and this just ends up speeding up the sulfation process.

    I thought 30-35% was a max for AGMs and flooded their max was more like 20-25%. Either way solar is cheap and getting cheaper. Batteries are expensive and getting more expensive. Gone are the old days of cheap batteries and expensive solar. Now it is cheap solar and expensive batteries. I'd push for 15-25% solar amps vs battery C/20 amp hours. Solar's cheap if you get full size 60 and 72 cell panels.

    I usually recommend if you are going to spend 8-20K on a battery bank, spend the 100-200 on a good quality refractometer.. many are temp compensated at this range and much easier to use than a Hydrometer. You also don't get the cross contamination issues you would see with a Hydrometer. Extech Make and RF41 that's pretty reasonable.

    I might get one. This one seems reasonable. i'll comparison shop. Hydrometers are clunky and tedious. The Deka hydrometer is glass and has a temperature compensator but I only use it for one cell. It takes several attempts to get a enough acid to make the bobber float. The EZ-Red is very easy to use though dogs like to chew it if left out. Hydros are a lot of work. I have never measured every battery cell in one session. I usually pick 'right, center, or left' and measure 4-6 random batteries. I know I have two weak batteries (One was weak from the beginning and its relocated to the end of the string, the other was overwatered - didn't expect the auto-stop on the filler jug to not work - and overflowed several ounces of acid from the right cell and 1-2 ounces of acid form the middle cell during charging) and there are 4 strong batteries (SGs run higher than the others, don't remember which ones exactly but two are the 2nd & 3rd batteries in the string in the right box). I got my batteries cheap - S-530s for $288 each. $600 for drop-shipping all 16 of them from Canada. Probably $6.5K when adding in other costs like the 4/0 cables, battery boxes, and customization to the battery boxes (labor, materials). $5.2K just for the batteries.
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    Why the insane voltages? I was reading chronic voltages this high are destructive to batteries

    I'm not Steve Higgins, nor do I play him on TV. But I was told both by our battery dealer and Surrette tech support that the charging specs that are published are based on the use of a IUIa profile industrial constant-current charger. Which our RE chargers most definitely are not. This was supposed to be part of the purpose of re-writing parts of the manual - to reflect the fact that RE systems do not typically have unlimited power available for constant-current bulk, and high voltage finish stages. RE chargers do not even have a finish stage - just float. And in industrial batteries float is not used - only for long periods of inactivity.

    Being that our RE chargers do not even have a finish stage you have to use higher voltages to prevent sulfation and eventual early death of the battery.

    The industrial chargers that the specs are for do:
    I = Constant current (bulk)
    U = Constant voltage (absorb)
    Ia = Constant current until the final voltage is reached (usually EQ voltage), then charging is stopped (finish stage)

    Without that finish stage you are not really fully charging your batteries.
    --
    Chris
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: I don't really like my Surrettes
    I don't perceive a good customer service reputation in the forums for Surrette. That's why I never bothered to talk to Surrette tech support.

    Don't believe everything you read on the internet, including this forum.
    I don't perceive a good customer service reputation in the forums for Surrette. That's why I never bothered to talk to Surrette tech support.

    You should make up your mind about their tech support by trying their tech support.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • SandyPSandyP Solar Expert Posts: 65 ✭✭
    Re: I don't really like my Surrettes
    ChrisOlson wrote: »
    Being that our RE chargers do not even have a finish stage you have to use higher voltages to prevent sulfation and eventual early death of the battery.

    The industrial chargers that the specs are for do:
    I = Constant current (bulk)
    U = Constant voltage (absorb)
    Ia = Constant current until the final voltage is reached (usually EQ voltage), then charging is stopped (finish stage)

    Without that finish stage you are not really fully charging your batteries.
    --
    Chris

    Just thought I would paste in some images of what Chris was referencing re charging:

    Note these are for my GEL batteries (including one of DoD vs cycle life)

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  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    SandyP wrote: »
    Just thought I would paste in some images of what Chris was referencing re charging:

    Thanks SandyP for those. It's a common misconception that using the published absorb voltage figures for our RE chargers will apply, when most times it doesn't. It depends on what charge profile the absorb spec is designed for, and this is not made clear in any manuals. For industrial type batteries where the charging specs are designed around IUIa profile, there is sometimes even a separate bulk voltage setting for the initial constant-current part of the charge cycle.

    The way our RE chargers handle this is very different. Most of the time there is not long enough periods of energy produced to fully charge, de-sulfate and re-mix the electrolyte in a battery using just the IU profile, and most times insufficient current available for the initial constant-current part of the cycle.

    It's a mess, and not very well understood unless you have worked with a real IUIa charger - then the light bulb comes on over your head and you go, "ahhh.....NOW I see the problem".
    --
    Chris
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: I don't really like my Surrettes
    ChrisOlson wrote: »
    It's a common misconception that using the published absorb voltage figures for our RE chargers will apply, when most times it doesn't.

    I had to dramatically increase charging voltage (to 64 over 58.8 recommended) because it didn't work any other way. With 58.8 I was looking at 20-30 hour absorbtions. I now look at it this way. Regular absorbtion doesn't do anything to my batteries, so I skip it. To compensate, I do weekly equalisations at 64V. If there's lots of sun this happens to be more often than weekly. I'm now working on making it less often. You need to do what you're batteries are asking for, not what manufacturer says in their datasheets.
  • Steve HigginsSteve Higgins Registered Users Posts: 13 ✭✭
    Re: I don't really like my Surrettes

    "I don't perceive a good customer service reputation in the forums for Surrette."

    I have to tell you that most manufactures stay away from forums because you just never know if you walking into an ambush, you just never know when it's going to turn bad. At Surrette we've talked about doing our own forum but we just don't have the manpower. At any given time there are 60 people in the company in total.

    "People say your techs always reply 'corrective EQ' as it was some magic cure-all."

    Yes, this is something that I'm in the process of changing, frankly I'm not or nor have I ever been a fan of pumping 2.6vpc into a battery. There are just way too many things that can go wrong. That being said, there are times its necessary as when your SG get more than .03 of a point off from each other. This usually only happens with systems that are not being charged any where near recommendations. I've seen systems that have NEVER been equalized while down the street the owner has to EQ every month.. Again it's all based on how that independent customer uses that system.

    "I was told these batteries were drop-shipped directly from Surrette and the Pallets had a Canadian sender address. I got the batteries in September 2012."

    What is the Manufacture date on the battery? It's usually a four digit code stamped into the post or on the side of the top lid? Wtih that Manufacture date, I be better able to understand where your SOC was when you first installed the system.

    "Why the insane voltages?"

    As I said, our plates are much denser and larger than any of the competition, when using a voltage controlled charger such as any RE equipment you need a higher votlage to get those batteries properly charged because when the inverter/controllers see that 57.6 volts they start to back off considerably. For your system I would set my base voltages to 58.8 for the inverters and 59.2 for the controllers.

    "They seem charged to 1.265, people in this thread say 1.265, but salesperson says 1.280"

    The Fully charged range is 1.255-1.280... To get these up to the 1.280 range you are going to have to hit them pretty hard with voltage over a pretty long period of time. 1.280 is where they are spec'ed at for industrial use because the current based chargers hit them a bit harder than an inverter based charger.

    "I got one other question. Is a 1.5V drop between open circuit and 36-50 amp load (18-25 amps each string and cable set; each string has separate 4/0 cable to DC busbars in PDP) excessive, even for surrette"

    1.5volt drop where? Across each cell? or the entire bank?

    As for the questions from Inetdog:

    "The consensus here so far seems to be to use the generator to bulk the batteries in the morning when needed to allow the whole solar day to be usable for absorb and/or finish instead of trying to keep the generator running wastefully for low amps."

    I would agree with this, as you don't want to be burning fuel to do this. If you are EQ'ing, or trying to maintain the batteries I would strongly look at using the genset as this power is much more predictable than solar.

    "Can you elaborate on generator use, with specific reference to the Surrettes? Would you favor going near the 30% rate when bulking with the generator to reduce running time, or to treat the batteries more gently and hold it down to 15%, for example? "

    Problem is this extra current is only going to help during the Bulk phase of the charging, because of the method of charging that all of the inverter companies have taken. Voltage based chargers are cheap but not as efficient as IUIa charging. Once you get into that absorb stage current is going to drop severely. In the end that extra current is only going to save you minutes, instead of hours. Systems that I Consult on I try to keep the charge ratios to that 10-15% or equal to the C5-C6 Discharge rate.

    Does the Xantrex Meter use a shunt to measure current? from what I seeing their meters are voltage based and not as accurate as you would want... How does the Xantrex meter determine end amps?
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    Does the Xantrex Meter use a shunt to measure current? from what I seeing their meters are voltage based and not as accurate as you would want... How does the Xantrex meter determine end amps?

    Steve - from studying our XW with the covers off it is apparent there is no shunts in there. I think they use current transformers to measure the AC side and calculate the DC side in software. At best I think they are maybe +/- about 5% accurate.
    --
    Chris
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: I don't really like my Surrettes
    The Fully charged range is 1.255-1.280... To get these up to the 1.280 range you are going to have to hit them pretty hard with voltage over a pretty long period of time. 1.280 is where they are spec'ed at for industrial use because the current based chargers hit them a bit harder than an inverter based charger.

    I just did an experiment on my forklift batts (not Surrette) today, they started the morning at 85% SoC, reached absorb voltage of 2.4Vpc at 11:30am and I left them in absorb for 6 hours. They finished the day at 1.280 SG (the manufacturer says fully charged is 1.29).

    I can understand that when charging time is limited you need to increase the absorb voltage above 2.4V, but if you had enough time isn't it better for the longevity of the battery to leave it at 2.4V for a longer time, rather than going with a higher voltage?
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    stephendv wrote: »
    I can understand that when charging time is limited you need to increase the absorb voltage above 2.4V, but if you had enough time isn't it better for the longevity of the battery to leave it at 2.4V for a longer time, rather than going with a higher voltage?

    I think Steve covered that pretty well when he said no two systems are alike. For us that definitely won't work because we try to cycle our batteries fully only once every 7-10 days. So we need to use 2.58 VPC to get ours where they should be, in the time we got to do it in. For somebody else that cycles their batteries shallower and more often, the lower voltage and longer time might work, assuming there is enough energy available to actually get the job done.
    --
    Chris
  • YehoshuaAgapaoYehoshuaAgapao Solar Expert Posts: 280 ✭✭
    Re: I don't really like my Surrettes
    SandyP wrote: »
    Just thought I would paste in some images of what Chris was referencing re charging:

    Note these are for my GEL batteries (including one of DoD vs cycle life)

    Attachment not found.

    So why aren't Outback, MorningStar, Midnite Solar, and Xantrex supporting the Ia / finish stage? I think they should support it. Just put in an option to enable/disable it.
  • YehoshuaAgapaoYehoshuaAgapao Solar Expert Posts: 280 ✭✭
    Re: I don't really like my Surrettes
    "I don't perceive a good customer service reputation in the forums for Surrette."

    "I got one other question. Is a 1.5V drop between open circuit and 36-50 amp load (18-25 amps each string and cable set; each string has separate 4/0 cable to DC busbars in PDP) excessive, even for surrette"

    1.5volt drop where? Across each cell? or the entire bank?

    Whole bank, open-circuit vs 36-50 amp load (18-25 per string).
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: I don't really like my Surrettes
    So why aren't Outback, MorningStar, Midnite Solar, and Xantrex supporting the Ia / finish stage? I think they should support it. Just put in an option to enable/disable it.

    boB at midnight solar indicated to me that they will have this feature at some point in the future. I have experimented with it, using Auto EQ in the Classic, to simulate the Ia finish stage. I have sent my results of what it did to boB, and how it works compared to the "boost charging" that XW uses. I did determine that the finish stage using the Auto EQ in the Classic works better than XW's "boost charge" at the front end of the absorb stage.

    boB said it can be done just in software and doesn't require any hardware changes. But he's got a lot of irons in the fire and it will not happen right away.
    --
    Chris
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: I don't really like my Surrettes
    So why aren't Outback, MorningStar, Midnite Solar, and Xantrex supporting the Ia / finish stage? I think they should support it. Just put in an option to enable/disable it.

    It's not that simple, because the final "I" stage has to be current limited to no more than 5A/100Ah. But charge controllers have no way of knowing how much current is actually going into the battery, so if they apply a current limit, and then you turn on a heavy load you'll start drawing from the battery because the charge controller has limited its output. Midnite have been promising an external shunt/battery monitor which will make this possible, so hopefully one day we'll have this feature.
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: I don't really like my Surrettes
    ChrisOlson wrote: »
    So we need to use 2.58 VPC to get ours where they should be, in the time we got to do it in. For somebody else that cycles their batteries shallower and more often, the lower voltage and longer time might work, assuming there is enough energy available to actually get the job done.

    The bit that's still unclear to me is whether Surrettes can be charged at 2.4Vpc if there was enough time to charge them, or is a high voltage absorb mandatory under all charging and discharging conditions?
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