48 Volt forklift battery

jabb
jabb Registered Users Posts: 16
:blush:
I have 24 @ SBY-85-13. (804 Amp hours at 20 Hr rate.) The charge rate is 45-105 Amps. I am not able to get my SG to 1.285 which is recommended by the Mfg weekly.
I think my settings may be too low and too short. I have been equalizing every 2 weeks trying to increase the SG.
GBI MFG Settings:
Float is 2.21
Absorption is 2.35 for 1 hour
Equalize is 2.38 for 4 hours
The voltages appear to be 100% all the time on my Flex Net DC monitor. The SG does not agree, usually 1.240 to 1.270
Does anyone have experience with these or similar Forklift Battery settings?
Thanks, any help will be appreciated.

My system is 2 MX60 controllers with 4880 watts of solar power, a Hub 4 and Mate with a Flex Net DC monitor. The inverter is a SW5548 and the generator is 11kw Isuzu diesel. I use a 48v pulse charger on the batteries at all times.
«1

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: 48 Volt forklift battery

    I suggest you up the Absorb time to the maximum 4 hour limit. The MX60 "counts up" from when Bulk starts until Absorb Voltage is reached and uses that as its Absorb time. But if it is longer than the Absorb limit setting (1 hour in this case) that will take precedence. Long Absorb times are necessary for high capacity batteries.

    Also your Absorb and Float Voltages may be just a tad low, depending on what the battery manufacturer recommends. I'd suspect it ought to be 2.4 or a bit higher for Absorb and 2.3 for Float.

    Equalization should be done until no improvement is seen. As in EQ for an hour, check for cell improvement, EQ again until there is no increase in SG. Likewise your EQ setting may be a tad low. Might need to be 2.5 Volts.
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: 48 Volt forklift battery

    Hi Jabb,

    YES, all of the numbers seem to me to be a bit short. But, the manufacturer should know. Wonder where you found these numbers. I have no experience with that battery, and found almost nothing in doing a search of the net.

    You might also look at other Forklift batteries which have similar 1.285 SG for additional guicance. Usually the manufacturer knows best about their batteries. Many manufacturers tweek their chemistry a bit, so this might only be a bit of guidance.

    But the low numbers, particulary the EQ V and the Asorb time seems off. The SG pretty much tells all about how they are being charged.

    YES, high capacity batteries, which are cycled fairly deeply, need longer Asorb times, but the same battery which is lightly cycled (only taken down to 90% SOC, lets say) does not, if the charge voltages are reasonable. My medium sized bank usually needs about 1.25 hours of Asorb-- but they are lightly cycled, usually.

    It is all realtive. Good Luck with those batteries.
    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.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: 48 Volt forklift battery

    nobody asked how old the battery is and if it has been well charged in the past with periodic maintenance.:confused:
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: 48 Volt forklift battery

    What 'coot said, absorb should be at about 2.4V and EQ should be upwards of 2.6V. When you follow the manufacturers advice double check that they know you're using an "IUo" charge curve (constant current, then constant voltage). Some forklift manufacturers give the charging specs for their own chargers which use different charge curves.
  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    Re: 48 Volt forklift battery

    I would charge them up to atleast 2.4v per cell even 2.45v and let them absorb until the amps going in dropped to 1% of the capacity of the bank, 8 amps. If the batts will drop that low then they are probably in good shape. If they won't get down to 1% then you probably have some sulfation problems, and equalizing may help with that.
    Good luck with them.
    Larry
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    :D Thanks for all the great info. I think the Mfg. (BBI / GB) is new at Solar and I have asked for a charging algorithm for Solar, but they have not provided it. I just installed the batteries new in 11/2010. They were 1.125 when received and I have had them up to 1.280 SG last week by warmer temperatures of the batteries between 105 - 110 degrees Fahrenheit and Equalizing @ 2.5V per cell for 3 hours.
  • mikeo
    mikeo Solar Expert Posts: 386 ✭✭✭
    Re: 48 Volt forklift battery
    up to 1.280 SG last week
    I have noticed some lag in SG reading while charging my forklift battery. If you have 1.280 right after charging, check the next morning if there is no load on them and you may find them at 1.285 or even higher. I don't know why this is the case, maybe someone out there would have an explanation for this increase in SG.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    Thanks Mike,
    I'm wondering if resetting to the default settings of the MX60 would be more appropriate.
    I'll check my SG again in the AM after EQ, and see if mine are similar.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: 48 Volt forklift battery

    This is a pure guess, but I wonder if it has something to do with stratification. What I've seen with my forklifts is that even after a long absorb they only sit at 1.26. But after 15 minutes of EQ at 2.6V the SG is 1.275. There's no way it could actually have charged that much in 15 minutes which is why I'm guessing that the higher density acid at the bottom of the cell was mixed around and brought to the surface.

    Haven't spent enough time verifying this theory though, so will update when I try it again tomorrow :)
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: 48 Volt forklift battery
    stephendv wrote: »
    This is a pure guess, but I wonder if it has something to do with stratification. What I've seen with my forklifts is that even after a long absorb they only sit at 1.26. But after 15 minutes of EQ at 2.6V the SG is 1.275. There's no way it could actually have charged that much in 15 minutes which is why I'm guessing that the higher density acid at the bottom of the cell was mixed around and brought to the surface.

    Haven't spent enough time verifying this theory though, so will update when I try it again tomorrow :)

    We have a winner! :D

    Remember that some forklift batteries run with pumps to mix the electrolyte. I think john_p even did a test on this a while back. In this thread somewhere: http://forum.solar-electric.com/showthread.php?t=9733&highlight=forklift+air
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: 48 Volt forklift battery

    Victron's new inverter/chargers now have a charging profile specifically for tubular plate traction batteries, which is described in the attached pic. I wish the same thing were integrated into a solar charge controller....
    At the moment, I've reprogrammed my morningstar MPPT to sort of mimic their charging idea. Absorb at 2.4V for an every-day charge, then perform a short EQ at 2.7V every 10 days.
    There's also specific advice on charging traction batteries in their whitepaper: http://www.victronenergy.com/upload/documents/ElectricityonBoard_rev8_july2004.pdf
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    :DThank-You for this information. How long do you set your aborbption time? 1, 2 or 3 hours? When I talked to the manufacturer BBI, this is how he replied to my questions.

    1. I need to know the charging algorithm to make them compatible with my charge controllers/Inverter.

    We do not have an algorithm requirement on the batteries.
    2. What is the Absorption Voltage and charging Time?

    Absorption Voltage, we are not familiar with this term. Charging time is dependent on output/temperature from your rectifier. SBY 85/13 cell types are 510AH@8hr rate.
    3.What is the Float Voltage?

    Batteries can float at 2.2VPC/77F.
    4.What is the Equalization Voltage and charging Time?

    Equalization is met at max. 2.6VPC, time dependent on temp/age factor.

    I have the Minimum-Maximum charging Amps @ 45-105 from The BBI website but not the other information.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: 48 Volt forklift battery

    Currently my battery is cycling very very lightly, so only absorbing for 30 minutes every day. Once it starts proper cyclic operation, I'll have to check experimentally how long it takes for absorb to charge the bat 100% on a typical day with a hydrometer. I'm guessing about 3 hours.

    I also can't get much of an answer from the manufacturer about the optimal settings for a standard bulk-absorb charge because their forklift chargers don't use that method of charging (AFAIK, they use a continuous gradual tapering current charge). From the information in victron's paper, once my bat starts cycling I'm going to try and follow the following charge regime:

    Daily:
    - Bulk to 2.43V
    - Absorb for 3 hours (to be determined experimentally)
    - Float at 2.2V

    Every 10 days:
    - Bulk to 2.65V
    - Absorb for the usual amount
    - Float at 2.2V

    Every 3 months:
    - EQ to 2.7V
    - EQ for 4 hours, checking SG all the while and terminating charge if all cells stop rising.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    Thanks again for all your help. I have been getting my SG up to about 1.280 by equalizing every two weeks. I also check each hour to make sure it's going up. I stop when the temperature reaches 110 degrees F. Sometimes that only takes an hour. The SG seems to drop to about 1.130 during that two week time. My Flex Mate DC Monitor, shows I'm at 100% all the time, so I have to depend on SG readings to get more accurate info.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: 48 Volt forklift battery

    Hehe, I don't know if I would call it "help", I'm muddling through this stuff just like you :D

    If the SG is dropping during that 2 week period then you could probably increase the daily absorb time a bit.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    Well I think it is a lot of help. I am so frustrated with all the different information I get. I'll probably have to read the White Paper 4 times before it all sinks in. I'll try increasing my absorb time and let you know how that goes.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: 48 Volt forklift battery

    I just bought half your battery from the same people ( they really have no clue on solar use) I my 24 volt did arrive with all but one cell reading 12.85 or better which is the speced SG on the side of the battery. A 2 hour equalizing brought that cell up to 12.85. Is your SG listed on the side of the battery?

    I did not change my previous settings, asborption at 28.4 Float 27.4 (I think, I raised this to about max as my batteries aged, so maybe I should check this) and Equalize at 30.8 or 31. If asked to equalize every 10 days I think that would be for industrial uses with the battery being brought down to 50% DOD or greater regularly. I left my equalizing at every 30 days.

    When did you set up your mionitor? The battery should be fully charged when you discribe it as such, you monitor may never have been correctly setup, also did you use the 20 hour rated capacity when discribing your batteries capacity? Should be 800-810 amphours for solar uses and discripitions.

    I'm just guessing, but perhaps they use a lower voltage due to the high charging rate often seen, perhaps by keeping the total wattage down they lower the heat buildup then charging these batteries when used as forklift batts.

    Please remember we are not treating these batteries as they were originally intended!

    On Battery care their first line after the heading "Proper Battery Care" sub heading "Charging" is;

    "Under normal circumstances, we recommend charging when a battery reaches 80% depth of discharge (near the “red zone” on most discharge meters), not before. "

    The third piont is;

    "Select “weekend”, “equalize” or “weekly” charge (depending on your brand of charger) approx. every 5 to 10 cycles to keep the battery performing at peak efficiency. Failure to do so or selecting this option too often will harm the battery and shorten its effective life. "

    I think the recomendation of equalizing every 10 days was based on this deep charging every day of a forklift batteries life. I'm worried that you are actually harming your battery by doing this too often and not addressing the problem.

    I did not see any recomended voltages, but perhaps I missed a link some where. If after equalizing your still have a low SG, I would worry that your battery is very under charged, they equalizing voltage that your discribing is very close to my daily absorption charge so I'll want to look into things as well.

    Do your batteries ever rest for a couple hours? if so what kind of voltage reading do you get?
    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.
  • mikeo
    mikeo Solar Expert Posts: 386 ✭✭✭
    Re: 48 Volt forklift battery
    Well I think it is a lot of help. I am so frustrated with all the different information I get. I'll probably have to read the White Paper 4 times before it all sinks in. I'll try increasing my absorb time and let you know how that goes.
    Hi I have DECA forklift batteries which should be about the same chemistry. Their recommendations for my batteries are:
    Float 28.0 volts
    Bulk 29.4 volts
    Eq 30.0 volts.

    This is much higher then many other deep cycle batteries. They keep telling me these batteries need to gas to keep healthy.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: 48 Volt forklift battery

    MikeO;

    It's not that far off from what Trojan recommends for their deep cycle batteries (24 Volt system figures):
    Absorb (Bulk) at 29.6, Float 27.6, Equalize 31

    I think what they mean by "these batteries need to gas to keep healthy" is the desire to get some serious bubbling going during charging to make sure the electrolyte remixes.

    And yes if the SG is dropping significantly between EQ cycles then you're probably not getting enough Absorb time or using high enough Voltage set point.

    Traction batteries are pretty tough and can take a lot of V, providing they don't boil dry. It's normal for these things to be discharged all day right down to 20% SOC, then brought back up over night (or vice-versa as some warehouses run night shifts).
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: 48 Volt forklift battery
    Photowhit wrote: »
    "Select “weekend”, “equalize” or “weekly” charge (depending on your brand of charger) approx. every 5 to 10 cycles to keep the battery performing at peak efficiency. Failure to do so or selecting this option too often will harm the battery and shorten its effective life. "

    I think the recommendation of equalizing every 10 days was based on this deep charging every day of a forklift batteries life. I'm worried that you are actually harming your battery by doing this too often and not addressing the problem.

    Spot on. This agrees with the Victron paper and with Crown battery's charging recommendations: http://www.crownbattery.com/PDF/Safety.First._Deep%20Cycle%20Batteries.pdf
    i.e. they have different voltage settings and EQ frequency based on how deeply the battery is discharged.
    Shallow discharge = lower voltage settings and less frequent EQ
    Deep discharge (below 50% SoC) = higher voltages and weekly EQ

    Based on this, I would revise my "every 10 days" plan to simply be a longer absorb at a slightly higher voltage than normal to ensure the batteries are 100% charged and mixed, e.g. if every day absorb was 2.43V for 3 hours, then every 10 days would be 2.45V for 4 hours.

    Cariboocoot, the distributor where I bought the battery from said pretty much the same thing as you: don't split hairs about 2.5V or 2.45V absorb voltages, these are tough industrial products not laboratory products.
    But I can't help thinking that getting the voltages just right could extend the batteries life by a few years, 50mV might not sound like much, but over a 20 year (hopefully) period, surely its effect will be seen.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    The battery salesman said they should be @ 1.285 every week. Their recommendation is to Equalize to get them to this SG.
    The specs on my battery are:
    Battery Type: 06-SBY-85-13-1317B
    Ser#: varies on each case
    AH Capacity: 510 AH (8 hour rate)
    Total Voltage: 12 (they are in four 12V cases in series to make 48V)
    Specific Gravity: 1.285
    Service Weight: 564

    I set up my Outback Power Flex Net DC monitor when I purchased the batteries in 11/2010. It is set for 800AH and 2% (16) return amps. It shows no (0) AH removed from the battery since installed, so I called Outback and they tell me I need another shunt to my Inverter, Dumb me. Once I install that I will let you know if it's working correctly or not. The batteries do go to float just about everyday.

    I've been told that these batteries can last 15-20 years in a solar application. You would think that someone who had such good luck, would step up and give their charge controller settings. It shouldn't be this hard and take so much time.

    The recommended voltages I got from BBI are 2.2VPC for float and 2.6VPC for Equalize, without a specific time. I was advised not to go over 2.32VPC for 1 hour for Bulk/Absorb or they will start an equalize cycle which counts against the 1500 cycle rating. The voltages are not listed on their website.

    It seems as though only a forklift charger could charge them correctly?
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: 48 Volt forklift battery

    jabb,

    Customarily, is best to rely on the battery manufacturer for charger settings.
    But, in this case, seems that they have no info on Solar charger settings.

    But really, carefully monitoring the SGs while changing the CC settings is the best approach. The Asorb time usually needs to be longer with greater depth of discharge. If you have enough solar charge current, the Asorb voltage should not need changing with changes in the depth of discharge.

    Later, when the batteries get into Float every, or almost every day, you can deal with your battery monitor.

    MHO is that a battery monitor is a nice tool to supplement SG measurments, but is no replacement for diligent measurment of the SGs on a regualr basis. And on a daily basis while you are adjusting charger settings to reach/maintain SOC.

    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.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: 48 Volt forklift battery
    jabb wrote: »
    Thanks again for all your help. I have been getting my SG up to about 1.280 by equalizing every two weeks. I also check each hour to make sure it's going up. I stop when the temperature reaches 110 degrees F. Sometimes that only takes an hour. The SG seems to drop to about 1.130 during that two week time. My Flex Mate DC Monitor, shows I'm at 100% all the time, so I have to depend on SG readings to get more accurate info.

    ANy SG below 1.15 is too low and indicate near dead battery! It looks like your taking out much more energy than your putting in.

    I think Mike has had a fork lift type battery the longest and has given you some settings, I think he has a 24 volt system like I do, just multiply by 2 for a 48volt system.

    I stated before and I'll state again it looks like your under charging your batteries. I agree you need to watch your SG. I asked earlier do your batteries ever rest? and what is their voltage at rest (even for an hour of no sun/no loads? this will give you some information as to your state of charge.

    I'll have a new hydrometer earlly next week, but I think all is well here to this point.

    If your continuosly finding your system in need of equalizing every 10-14 days and you can get the SG up with out resorting to a generator, you need to give your batteries more energy.

    I wish I had a longer experience with forklift batteries, but I have been off grid for 10 years now continuosly, I suspect BBI is use to over night charging of batteries drawn dow to 30% state of charge, and they use a lower voltage setting since they are applying 100+amps at 48v(nominal) where your drawing down your battery to 85% and applying 40Amps max nominal (starting much lower than that, I think you have a 5000 watt array?)
    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.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    When my batteries rest for 2-1/2 hours, these are my voltage readings: Total Voltage is 52.1 and SG's are 1.255 They just do not match the voltages.
    1=2.15
    2=2.15
    3=2.17
    4=2.15
    5=2.16
    6=2.16
    7=2.15
    8=2.17
    9=2.16
    10=2.16
    11=2.15
    12=2.16
    13=2.16
    14=2.19
    15=2.16
    16=2.17
    17=2.19
    18=2.19
    19=2.17
    20=2.16
    21=2.16
    22=2.16
    23=2.15
    24=2.18

    When I received these batteries they were at 1.125 SG so BBI, said I should equalize them to get them to come back up, which I have done. They do come up a little more each time I equalize but never over 1.280 And lately I have to stop because of temperature getting to 110 degrees F. Yesterday I got them to 1.255 SG's from 1.180 in about 2 hours at 62.V. I turned off equalization when the temperature reached close to 110 degrees F. They are all pretty much equal. My Solar Panels are 4880 watts (16 @ 180 on one MX60 and 5@ 100 and 5 @ 300 on the other MX60) I have been off grid since 2006. I ruined my rolls S530 batteries by equalizing too much at too high temps. The SW5548 Inverter will only charge at 39 Amps Max and I have the MX 60's set to there Max of 70 Amps. My voltages have never been below 47.4 and only for a very short time.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: 48 Volt forklift battery

    Just scary numbers after a 2.5 hour rest, I can't imaging a lead acid battery not dropping to it's max voltage which should be 50-51.2 volts. (Though my experience with these large batteries is short, perhaps they will take longer to drop back down.) And if your just out of Equalizing the electrolite should be well mixed.

    So I would go to suspecting your measuring equipment. I guess a cheap volt meter might have a 1/2 to 1% error? that could explain the high voltage, Are you using a suspended glass bobber type hydrometer?
    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.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    Yes your link is to my hydrometer. I also use an EZ-Read (which agrees with the glass Brady.) Mine is the temperature compensated one. I do have several digital volt meters and they all seem to agree, but they are cheap. What do you recommend?
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: 48 Volt forklift battery

    I honestly am in a quandry, I have been just generally eye balling my voltage, but my new hydrometer isn't here yet, I actually purchased a glass float type hydrometer (at O'Rileys auto parts of all places) but was going to check it against a real one first.

    The first time I could do an at rest check would be Wed. (I work afternoons and will be off Wed) that might give you a little more information. I'll check the SG Monday afternoon once I reach float and see if the SG is reading low, though I'll be using an unknown instrument on a 2 week old battery. If the reading is low it would give us some information. When the battery arrived I dids have 1 low cell at 1.260 or 1.265 and a quick 2 hour Equalization brought it up to 1.285 (I had broken my good hydrometer and used a throw away, I check 2 cells one that read high and the low one the high was still @1.3 and the low was up to 1.285.

    If there is anything else I can check, let me know, I have the 24 volt version 12-85-13 510Amp hours at 6 hour rate and 804 at 20 hour.

    I do a pretty good push pull this time of year, I likely draw as much as 100-150amp hours at 24 volts(nominal), though the battery may never get below 85-90% of charge, as some of that is AC during the day. This discharge/recharge would help mix the electrolite.

    Somethings odd, I really wish I could help more, The even SG across the board and the good if a bit high voltage, to me would indicate a bad/out of wack hydromiter. but you have 2 that agree, I'm just clueless...
    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.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    I have the identical batteries you do, twice as many. They still look great! They also have the dissipator caps, so have not had to add distilled water until this month. When you add the numbers up it is 51.93, but that is still close to the 52.1 that the voltage meter gives. I checked the total battery number first before going on to each individual battery and it does take a few minutes to measure and write down the voltages. I should check the total last, maybe? The SG has never matched the voltages. I rinse the hydrometer (with distilled water) 3 times before I start taking measurements. I use about 200 AH in the winter and 300 AH in the summer per day and the sun/PV is providing most of that from about 9AM to 4PM in AZ. Maybe I don't have enough AMPs to charge the batteries correctly. I'm also clueless.
  • mikeo
    mikeo Solar Expert Posts: 386 ✭✭✭
    Re: 48 Volt forklift battery
    I have the identical batteries you do, twice as many. They still look great! They also have the dissipator caps, so have not had to add distilled water until this month.
    Any chance BBI the company that you bought from has special "solar" version of their forklift battery. Could the battery acid strength be set at 1.125? This would change the charge characteristics of the battery and make it last longer. I don't know what this might do to the cell voltages though. I think the HUP solar one batteries on have SG around these values.
  • jabb
    jabb Registered Users Posts: 16
    Re: 48 Volt forklift battery

    Battery Type: 06-SBY-85-13-1317B, these are considered Solar Batteries, (SBY stands for Solar Battery) they are just put in cases with cables connecting them, instead of soldered. I asked when I received them because it stated everywhere that the SG should be 1.285 (it is even on a label attached to the container) and according to BBI at least every week. They just think I need to equalize them as high as 64V for as many hours as it takes to get them up. I have done this for 6 hours when it was cooler. 1 hour on the Gen, then 4 hours on PV, then final hour on Gen. It's too hot now, If I equalize for 2 hours they get up to 110 degrees F, and I stop it. I still try every two weeks.