does this hurt

rake1
rake1 Solar Expert Posts: 173 ✭✭
I was wondering if it hurts to take the leads off the array and connect direct to the battery to get a little more juice into the battery only on occasion. Keeping in mind not to let the batteries go up past 15v on my meter. Am just looking at a way to get some more charging out of a short period of sun. Now I am talking about in the absorption stage, in other words extending the Bulk stage a little longer than normal. I am thinking this because I really don't have the 5% min needed to get these to full charge I have 17 amps and should have min 20 amps. Also thinking this on days when sun is limited and will not charge to full using the normal parameters of your charge controller.
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Comments

  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: does this hurt

    You just don't gain enough to make it worth the effort, Most charge controller are pretty effiecent.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: does this hurt

    With a good MPPT controller, you will probably not gain any advantage, and most likely lose some.
    If you wish to do this, simply add a bypass switch to wire the PV directly.

    Tony
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: does this hurt

    Bypassing the controller is a quick and dirty way to "equalize" the battery bank. However, you will have to watch them like a hawk (current, temperature, voltage, bubbling, SG levels).

    My big fear is something happens to distract you and you forget for a day or three--And then have a big mess to clean up (both electrolyte and $$$ for battery/equipment repairs).

    I would suggest a 60 minute timer controlled switch/relay--But might be hard to find something simple/cheap at your DC power levels.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    I like the idea of a switch but like BB said I would at some point forget so I am saying no to that one. But back to the original question does it hurt the batteries to do this every other charge? I am talking only 1/2 hour longer in the bulk stage. What about equalizing every other charge for 1/2 hour at the end of the bulk stage? These Surrette 530 batteries I have are quite large,I tried this for 1/2 hour and I noticed little or no difference in the bubbles coming of these while charging direct from the array with 15.4v showing on trimetric meter.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: does this hurt

    What charge controller a you using, and can you change the parameters at all?

    Tony
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: does this hurt

    The batteries "control" the voltage... The solar panels "control" the current.

    As long as the batteries are in the "voltage/current" zone you want (and the batteries are "happy"), then there is no harm that I can see doing this.

    I do not believe in equalization unless it is required (some vendors ask for equalization ever 1-6 months)--Too much equalization is hard on the battery (erosion of plates, driving oxygen into the battery's positive plate grid causing corrosion, and using a lot of distilled water, raising battery temperature, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    I have a new Xantrex c35 coming this week and it is adj some I just don't know how much yet until I get it and start reading the manual. I know it can go as high as 15v in the bulk stage and I think it is 12.5 to 14.5 in the float stage.Is 14.5v to high in the float stage for these batteries?
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: does this hurt

    Question is, is this a solution in search of a problem? If you are getting through bulk and into absorb, what is it you are trying to accomplish? It sounds like your batteries are getting nearly fully charged anyway. I would guess in some aspects, the charger is "smarter" than you are.. No offense intended.

    Bottom line is you can't get more power out of the PV than the PV can deliver, and the controller losses are going to be quite small, in the grand scheme of things.

    Tony
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    well I have been told that there are people smarter than me but not a machine LOL. I am getting through bulk but not properly to low a voltage.Once I get the controller my problems may be solved, the controller I have now is going into absorb at 14.2v which is way to low for the Surretts, they want them closer to 15v. That is where all this came from with trying to get more into the batteries. So you can see I can get more power out of the array when by passing the controller I have now, but hopefully this is going to be solved with the c35's adjustability.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: does this hurt

    sounds to me like you were charging the bank without a controller and all you can do is disconnect the pvs when it hits the max voltage to the batteries. running the voltage higher than the absorb voltage is not recommended as a substitute for the lack of an absorb charge. this essentially gave it a bulk charge, but it never finished charging the batteries through the absorb stage, because you had no regulation. the cc will finish the charge to the batteries by regulating the voltage to allow an absorb stage to be completed. i hope you haven't been doing this deficit charging for too long as sulfation could set in.
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    The idea was just extend the bulk a little bit then hook up the controller to let it finish on it own. Almost like using a battery charger to get a good start in the morning. I think LOL
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: does this hurt

    rake1;

    You're talking about hooking the panels up directly to get the Voltage above the limit of your charge controller which is not high enough for Absorb on those batteries?
    It will work, but only to a point; you will not have a controlled Absorb stage at the proper Voltage. If you reconnect the controller after the batteries reach, say, 14.8 the controller will simply limit the Voltage again and you will go through Absorb at the lower Voltage, which is at the wrong level.

    The only way this will achieve the desired effect of higher Absorb Voltage is t sit there and watch it for two hours, disconnecting the panels when the Voltage creeps up and reconnecting when it starts to sink again. Essentially you will be acting as a PWM controller, except that you can't switch the connection anyplace near as fast and accurately.

    There's no substitute for a good charge controller.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt
    rake1 wrote: »
    Once I get the controller my problems may be solved, the controller I have now is going into absorb at 14.2v which is way to low for the Surretts, they want them closer to 15v.

    You will ruin Surrette's by absorbing them at 14.2 or 14.4. You will not hurt Surrette's by hooking the panels direct. You will not get more from the panels by hooking them direct. Get that absorb voltage up to at least 15.0 (15.5 is probably better) and buy another solar panel if they won't make it there. The extra solar panel is going to be cheaper than sulfating those batteries (if they aren't already).

    In my experience Surrette's are a bugger if they got sulfate on the plates from being absorbed too low too long. They will take everything you can throw at them to get their SG's up, including a generator or two. Once you get the plates cleaned up and healthy again, they're fine. But it does take higher voltage than most batteries.
    --
    Chris
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: does this hurt

    Hi rake1,

    Surrette made your batteries. You should listen very carefully to Surrette, IMHO.

    For a 12 V system, Surrette recommends; 14.4 nominal for Absorption, 13.14 for Float, and 15.5-16 V for EQ.

    When using the Charge Controller as the charger, the above voltages should be Temperature Compensated. Does your current CC have a Battery Temperature Sensor?? Will the C-35 ?? This BTS is very important unless the batteries have a very stable temperature.

    Many off-gridders do Opportunity Charging in Fall/W'inter months, where the Absorption V is increased, because shorter days often do not allow the required Absorption TIME, and a higher V allows more charging to occur in a shorter time. This higher voltage charging can cause more water to be used by the batts, so keep an eye on it.

    While I do not want to argue with anyone, ... BUT, if you are in doubt with the printed Surrette recommendations for charger V settings, please, please call or e-mail them. They DO give very good Tech Support.

    Believe that Chris Olsen is using an uncommon Surrette battery which is Lead-Calcium, which would require significantly higher Absorption V for Cyclic uses. To get them to gass (which is desireable), he needs to set the Absorb V at or near the EQ V setting. I have never seen any Surrette FLA batteries that were Lead-Calcium, and believe that almost all Surrette FLAs are Lead-Antimony, which gasses easily at more customary voltages. Above just my opinions. Just FYI, if my bank can get its full Absorb stage, about 14.5 V per 12 volt battery is all that is required. On neighbor's systems, this is also the case, although higher settings are often used in Winter, but we are talking about a few tenths of a volt increase per 12 V battery. Again, these charger voltages really need to be temperature compensated.

    And, when you feeling flush, perhaps you can invest in a high-end CC, which has charge settings to one tenth of a volt. Batteries are expensive, and anything that can allow you to fine tune voltages and times is a good thing, again IMHO. YMMV Good Luck, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    As usual great info thanks. I was just trying to get a little more, but it appears I should leave well enough alone and let the controller do the job. My c35 is adjustable and I did order a battery temp sensor with it. I guess the only way I will know if the controller and panels are doing the job is check with my hydrometer after a good day of sun is that correct? I find checking voltage with my clamp meter not very accurate as it will show 12.8v ( a fully charged battery) quit easily but doesn't seem to have the staying power a lot of times which to me means not really fully charged. You mentioned in the winter months turning up the controller a bit because of the length of time I get the sun. I have attached the specs. of the Surrette batteries, what would you suggest as an increase in these months. Keep in mind I can only go to 15v with my c35 controller.

    State of Charge & Charging - Flooded Lead Acid Batteries

    State of Charge and Charging

    The truest measure of a battery's state of charge is the SPECIFIC GRAVITY of the battery acid. The following shows the approximate state of charge at various specific gravities at 77ºF / 25ºC.

    Charged Specific Gravity
    100% 1.255-1.275
    75% 1.215-1.235
    50% 1.180-1.200
    25% 1.155-1.165
    0% 1.110-1.130



    Hydrometers can be difficult to use and at best accurate to +/-0.005 points. Voltage can be used to estimate state of charge but caution must be taken when interpreting voltage readings.


    All Amphere Hour capacities based on specific gravities of 1.280. Reduce capacities 5% for 1.265 specific gravity and 10% for specific gravities of 1.250


    We recommend a three step charging procedure. Recommended voltage settings are as follows:

    3 PHASE CHARGING PARAMETERS

    SYSTEM VOLTAGE
    Charge Phase
    Temperature

    Volts per cell
    12v---- 24v
    48

    Bulk
    & Absorption 0˚C to 16˚C
    2.5 V -- 15.0 V 30 V -- 60 V


    17˚C to 27˚C
    2.4 V 14.4V 28.8 -- 57.6V
    28˚C to 40˚C
    2.36V 14.16V 28.32V 56.64V
    Float
    2.19V 13.14V 26.28V 52.56V

    Equalization - 2.58 -2.67 (max) 15.5-16.0 V 31.0-32.0V 61.9-64.1 V



    Sorry didn't come out great 12v

    Bulk and absorb 0c to 16c 15v
    Float
    13.14
    This my temp most of the time
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: does this hurt

    If you haven't already done so, I encourage you to read these:

    http://www.windsun.com/Batteries/Battery_FAQ.htm#Lifespan%20of%20Batteries


    http://www.batteryfaq.org/

    Tony
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: does this hurt

    OK rake1,

    Yes, I ran out of time to find the link to the above on the Surrette site, good that you have it.

    The temperature compensation on the CC should be automatic, so you should be able to set the desired charge voltage and the CC should compensate it for the measured battery temp (just to be clear, you probably know this).

    And, personally, I would ignore the SOC vs voltage chart, as these voltages are for rested batts, which is difficult to do when off-grid.

    The Hydrometer is THE TOOL for determining SOC.

    I do forget if you do have a Hydrometer, and if you have taken the SGs of the entire bank recently. Will try to study your previous posts to find this, plus your location, present CC and Inverter, etc.

    Do you know what your loads are (ideally, those taken from the batts)? This would help you know just how much you need to return to the batts (plus some extra to;accommodate inefficiencies).

    More later - Thanks, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt
    Vic wrote: »
    Surrette made your batteries. You should listen very carefully to Surrette, IMHO.

    Vic, I'd like to point out that Surrette's recommendations have been notoriously inadequate and a lot of people have ended up with problems with them because of it. You have to almost wreck a bank, then get Surrette tech support on the line, and then they give you different recommendations that work. And if you did wreck some batteries it's like pulling hen's teeth to get them replaced under warranty anymore because the first thing they want you do do is run corrective equalizations for several weeks on badly sulfated batteries to see if you can bring them back from the dead.

    Surrette has some SERIOUS issues and IMHO they had better get it sorted out or get out of the RE battery market and just stick to traction batteries.
    --
    Chris
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    This time of year I can get a good three to four hours of full sun 17amps in my case. but will receive six to seven hours of low amp sun all together. The Surrettes are 400 ah at 20hr rate and I now pull out about 10amps for about 5 hours a day. And yes I have a Hydrometer but haven't got my new batteries yet to check them. I had new ones that set for six months with no charge and the reading were low so I have returned them to the dealer and waiting for my new ones now. Chris based on what you said about Surrette do you have a voltage they should be charged at? Or anyone that has been in contact with Surrette that may be able to help.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt
    rake1 wrote: »
    Chris based on what you said about Surrette do you have a voltage they should be charged at? Or anyone that has been in contact with Surrette that may be able to help.

    The saga with our bank goes back to when we bought it. I had the absorb set at 28.8 (we had a 24 volt system then). I could never get the SG's up. So after three months I called Surrette and they gave me an absorb voltage of 31.0, minimum time 2-4 hours. It took a full month of absorbing them at 31.0, plus equalizing every time we had enough power, plus using the generator when we didn't, to finally get the SG's up to 1.255. I've been absorbing at 31.0 (62.0 now on our 48 volt system) and never had a problem since, and that was two years ago.

    My experience with Surrette batteries is more the norm than the exception. Everybody that has them has found out they will sulfate and die if you use the same settings as you would for Trojans (or follow their published charging voltage recommendations).

    So the first thing I'd do is fully charge them (what you think is fully charged) and check the SG's. If they're low, you got a problem, buddy, and you're in for a long baby sitting session with your batteries to bring them back. You can call Surrette and the first thing they'll tell you to do is a corrective equalization at 16.5 volts.

    The thing is, most people fail to read the fine print in Surrette's propaganda and it says right in there that 14.4 for a 12V battery is MINIMUM if long absorb times are available. Well, they got a formula for those long absorb times and it's ridiculous - more hours of sun than you get in a day. The fine print says that if short absorb times are more the norm (real world off-grid) then the absorb voltage has to be increased.
    --
    Chris
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    Re: does this hurt

    Geez Chris, 62v is what I eq charge my Surrettes at, 58 for absorb. How much water do you go through with that absorb voltage? Are yours the Ks tall boy 2v cells? Mine are the 8v CS type. 2 cells replaced under warranty, a couple of laggers now and then. Presently (not summer) i have them floating overnight on utility power and floating if the days are cloudy (biting the bullet on the power costs).

    Ralph
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    Mine are the 530 6 volt 400 ah anyone have experience with these and what setting are you using? Again they show Bulk and absorb 14.4 to 15v and Float 13.14, these things are to expensive to ruin so any hel on the 530 would be appreciated.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt
    Ralph Day wrote: »
    Geez Chris, 62v is what I eq charge my Surrettes at, 58 for absorb. How much water do you go through with that absorb voltage? Are yours the Ks tall boy 2v cells? Mine are the 8v CS type. 2 cells replaced under warranty, a couple of laggers now and then. Presently (not summer) i have them floating overnight on utility power and floating if the days are cloudy (biting the bullet on the power costs).

    Mine are T12-250's. The amount of water they use varies. In hot weather in the summer they'll use maybe a couple gallons in three months. In winter they don't use any. They would've been ruined by now if I hadn't caught the fact that their SG's were never getting above 1.215 when they were young, and I became alarmed over it.

    Off-grid is different than grid interactive systems. Batteries rarely, if ever, float on off-grid systems because our "grid" is the generator. And it is not unusual for off-grid batteries to cycle for days between 50-80% SOC. When that "good day" comes there's usually a limited amount of time available to get them thru a full absorb cycle. So higher voltages are required to get it done. If you apply Surrette's formula to the required absorb time it would take us 7-8 hours at a lower voltage. That just don't work here, except once in a blue moon. When you got grid power and you can simply flip a switch and take the load off the bank, it's different.
    --
    Chris
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt
    rake1 wrote: »
    Mine are the 530 6 volt 400 ah anyone have experience with these and what setting are you using? Again they show Bulk and absorb 14.4 to 15v and Float 13.14, these things are to expensive to ruin so any hel on the 530 would be appreciated.

    Again, get the hydrometer out. That tells the story. If the SG is not getting up to at least 1.255-1.260 you have to do something different. At that point call Surrette, tell them what you got, and see what they say. It's just my opinion maybe, but these "corrective equalizations" that they want you to do for batteries that get chronically deficit charged are a bunch of hogwash. A "corrective EQ" gets the batteries hot, acid fumes, and it's a long drawn out, messy (and expensive when you have to use a generator) process. And it's hard on the batteries.

    And yes, I know at least one member of this forum who (had) S530's and they went belly up before their time - Volvo Farmer. He can probably tell you how unimpressed he is with Surrette. IIRC he had his absorb voltages cranked up towards the end of their failure, but it was probably not soon enough to save them. He's got Trojans now, and if I had it do over again, that's what I'd have too.

    FWIW - this is where VF's saga started with his four year old S530's:
    http://forum.solar-electric.com/showthread.php?14068-Battery-equalizing-rotating&highlight=volvo+farmer+surrette

    In the end it was a mess because Surrette told him he could mix a new battery with old ones. And I don't remember all the gory details. But it's just one more classic "less than good success" story with Surrette batteries for RE off-grid systems. So all I can say is if you suspect you have a problem, get out that hydrometer early so you know what you got. And if the hydrometer does not show what it should get on the phone right away with Surrette and get it solved, and get their recommendation to solve it, so if you have warranty on your batteries everything you have done is documented for the warranty coverage.
    --
    Chris
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    Thanks Chris I did get a hold of Surrette here is what they told me for my application after I told them what I have 2- 530's and 17 amps from the array. Am I right in saying the guts of this thing is trying to get to the absorb as quick as possible? Float will look after itself if I can achieve absorb.

    Ok,
    You will then have a 400 ah (Dicharge Rate @ C20) 12 Volt battery bank.
    Ideally you will need at least 35-55 amps of available current to properly
    charge this battery bank within a reasonable time. At 17 amps it will take
    up to three days of good sun just to recover from a single bad sun day.

    I would set your Voltage to:
    Absorb Voltage 14.7
    Bulk Voltage 14.7
    Absorb Time 10 hours.
    EQ Voltage 15.5
    EQ Time 4 hours.
    Float Voltage 13.1
    Float Time 2 Hours.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt
    rake1 wrote: »
    Bulk Voltage 14.7
    Absorb Time 10 hours.

    This is the bad part right here, the way I see it. For us it was like 8 hours absorb time, which we cannot do. So it required the higher voltage to get it done in 2-4 hours. I've been absorbing for 2.5-3.0 hours @ 62.0 volts (on our 48 volt system) and the SG's are fine when it is done with absorb. So again, the specific gravity is what tells if the job got done properly.

    The higher voltage gets temp compensated down to 56.5-57.0 in warmer weather, but the batteries still use a couple gallons of water in June/July/August at that voltage. But that's what it takes to get the SG above 1.255-1.260.

    What's bad about this is that once absorb is started it should be finished. If you only get part way thru, then come back later and try it again, your efforts are nullified and you start over. If you don't mind running your generator all the time to get it all the way thru absorb, that's fine. But that would put a lot of hours on our generator. So the end recommendation for us was to bump it up to 15.5/31.0/62.0 for 12/24/48 volt systems. The higher voltage forces more amps into the batteries to get the job done during the peak of the solar day so the bank can reach float by mid-afternoon.
    --
    Chris
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: does this hurt

    Hi Chris,

    We are in agreement with number of things. I respect that you are a technical person, with excellent breadth and depth of knowledge and experience, and I am not trying to pick at you ... but,
    Surrette's numbers work fine here. These charge voltage numbers are not for deficit charging. The expectation is that each recharge is complete in one day, IMHO.

    If recharge cannot happen on one day, then one is in the Opportunity Charge camp. Crank up the Absorb voltage to get as much charging done when you can, and completely recharge the bank several times per week. MEASURE SGs to determine how the charger settings are working. When in doubt, measure SGs of a Pilot cell or a few daily until you get a handle on how the bank is doing.

    Chris, in other Threads, believe that you stated that your Surrettes were Lead-Calcium, which are generally called Low- Maintenance batteries, and gass llittle, and therefore use little water. Have thought that Flooded Lead Calcium batteries were not common for Cyclic uses, and as stated before, did not know that Surrette made any of these, except perhaps as Locomotive Starters, which are essentially in Float service ... dunno.

    rake1, the "C" bank here are Surrette S-530s (4000 Series). They are happy with the 14.4 per 12 V, or perhaps 14.45 V, but, of course, Temp Comped.

    A few years ago, almost all of the off-grid systems of neighbors here used Trojans. Trojans were the most-ruined batteries that I saw. This was not a problem with Torjan (probably), but, that the batteries seldom got recharged, EQ, or watered, and in a couple years at best, they were ruined. They were all under PVed and all had C-whatever Xantrex CCs. No one knew the correct Morse Code of the flashing lights, and all was well until the "Lights went Out", and so on.

    I have seen Surrette go way above and beyond anything reasonable in doing Warranty Replacements on banks of batteries. Am happy with the Surrettes in use here. They are not common in neithbor's systems, but those that are in use here, the seem to do well. Am not a Surrette shill, but they do work for me.

    Did run one Surrette bank here at 58.6 for about five days. It used an astonishing amount of water for that period of time -- had been trying to use EA on a new CC, and had actually been undercharging the bank for more than a week. Was trying to make up for that and stepped up the Absorb V, but did use EA. The banks here get to Float almost every cycle, and about 58.1 is about fine. Perhaps will need to crank back on this as well, but am more in the Opportunity charge camp now that are more cloudy days.

    We ALL do things that damage our batteries. There is no way around it. It is just a matter of how long they will put up with abuse. Under charge hurts them. Overcharge hurts them. EQing hurts them. Not EQing them hurts them. Letting them sit hurts them. Floating them hurtrs them ... just a matter of relative hurt, and some balance in just how and how often we hurt them.

    Opinions, but pay attention to your batteries, and measure SGs often ... Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt

    Our batteries are also 4000-series.

    I know of one friend I have in Canada that has some old telco batteries that are lead-calcium grid. His bank is 21 years old and he has never added a single drop of water to them. He absorbs higher than I do at 32.0 volts (24 volt system). At 21 years old, his bank still does not show signs of giving up the ghost. What's really funny is that he bought those batteries from the junk yard when they were 7 years old. The telco had replaced them and there was nothing wrong with them.

    But getting back to the the topic, our batteries had the same recommended voltage range of 14.4 min, 14.7 nominal and 15.0 high. They did NOT say anything about them being lead-calcium grid until they told me to bump it up to 15.5 (per 12V battery) in order to get the SG up. So I have the feeling that Surrette does not necessarily give you "the rest of the story".

    As usual, it's the hydrometer that tells. Without it, I would have never known that my batteries were being deficit charged. The amount of capacity they gained once I got the SG up was very noticeable. If I would've went by voltage they'd be doing the crappie flop right now.
    --
    Chris
  • rake1
    rake1 Solar Expert Posts: 173 ✭✭
    Re: does this hurt

    Thanks Vic nice to see some one happy with their Surrettes I was getting a little worried with my purchase but I know like anything else there is good and bad stories. My situation is different than most I think, as this set up is at my camp so I do have a longer time than most to get my batteries back before the next use. Usually 4 or 5 days before I am back and sometimes a couple of weeks or more depending on the season. Deer hunting just ended so I was there every weekend for six weeks but only had the Surretts for one weekend. With all being said I am considering another panel 195W good for 10 .4 amps that will bring me up to 27amps on a good day and that should definitely do the trick for me. Just another $500.00 on top of the $800.00 for the batteries and the $130.00 for the C-35 CC and $450 for the inverter I blow up by forgetting to unplug the inverter when I started the Generator. Not bad for a month for a system I have had for two years but decided to tweak it a bit LOL. I appreciate all opinions
    Is there a one way switch I can buy so the power from the gen cannot mistakenly go to the inverter if I forget to turn of the inverter switch again???
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: does this hurt

    I assume what you need is a transfer switch. You can build an economical one out of a 100 amp SquareD QO LoadCenter panel (about 25 bucks) with two double-pole breakers in it, and a SquareD QO2DTI breaker inter-tie that insures only one breaker can be on at a time. Generator feeds one breaker, the inverter feeds the other, and loads are connected to the buses in the panel. This a break-before-make type setup so the power will go out to your loads before the switch is made to the other source.

    For reference, this is the QO2DTI interlock:
    http://ecatalog.squared.com/fulldetail.cfm?partnumber=QO2DTI

    SquareD has used them for years for small generator transfer switches in their QO panels, as well as used by Xantrex in the ACCB for their inverters for the bypass. It clips on one double pole breaker and forces either one off before the other one can make contact. Or you can turn both breakers off and shut off both sources of power. But you can't turn both breakers on at the same time.
    --
    Chris