Battery Usage in the winter months Here in the North.

shawnj72
shawnj72 Registered Users Posts: 64 ✭✭
Hello, I have a question concerning Battery Usage in the winter Months. I have a Conext 6848+ two MPPT 60 150  and Two roughly 4500W Arrays. My Question is the Battery's Forklift 24-85-13 I believe. Since Late November to Probably Late February we may only see a couple days a month sunshine if any. Running the battery's and expecting enough sun to charge would be a miracle in itself. Granted I could charge them with the Generator. but the question is trying to keep the batteries at their best. A Letting the batteries sit for more than a month is bad. B letting them float for month is bad also. Would it be best to maybe cycle them every week or month and charge them back up with the Gen. My plan was to have a backup system and it has payed for itself as two weeks ago we got socked and half Of the Upper Peninsula was without power Cold and some for more than a week before it was restored.. Should i cycle them use them every week or month or charge and let them sit and recharge. What is the recommendation that will help maintain my investment and make sure it is still usable when i need it..Thanks A Bunch    

Comments

  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,142 ✭✭✭✭
    What makes you feel that sitting on float is bad?

    Marc
    I always have more questions than answers. That's the nature of life.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Do you have grid power?  Letting batteries sit in a cold environment is not as bad as warm, keeping them in float is not necessarily bad, it's just not using their potential, one has to remember batteries can die of old age without ever having been cycled. Cycling once in a while will stir electrolyte when recharged, especially important in tall cells such as forklift batteries, so it may be beneficial to do so, as long as there is sufficient recharge capacity. Generator charging becomes inefficient post bulk charge as current tapers down and extremely inefficient past that point.

    Reading between the lines this is a backup system to cover the occasional grid failure, please elaborate, it would be helpful.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • shawnj72
    shawnj72 Registered Users Posts: 64 ✭✭
    Thanks for the Reply, The batteries are in a 70 degree environment 99% of the time give or take 5 degrees.  They are in the basement in a controlled compartment per say. Temperature on the battery ranges between 65 and 78 while charging. Plan was to utilize them as a backup system and more as a supply system in the summer months. Yes the system has grid and is tied also so i could potentially charge using the generator 13kw or the grid if needed. I thought while in the winter months take a day every couple weeks or month and run a Cycle and charge them in the evening. It takes a good 4 hrs or so to do a complete from 50% starting at about 85 to 90A. I usually start the Gen every week or so to make sure everything checks ok anyway. Its hooked to a 500lb pig and i have to use at least one tank a year to not be penalized so kind of gives me an excuse to kill off some cheap propane. As for half the price of the tank is the surcharge for not using 1 full tank a year. .. As I heat with wood and water is heated through the boiler so i use none . I had it filled twice in 6 years. I don't really want to use grid power to Charge if i don't have to as what the power co charges might just be a trade off as which one is less efficient. I do know the sun isn't going to charge anything that big from November to February.  
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    There are some strange sets of economy here...put simply, keeping them on float is not going to be a problem. Is would charge from the grid since you have it, except when you exercise the genny.  Burning “cheap” propane is false economy imho.

    icarus
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    icarus said:
    There are some strange sets of economy here...put simply, keeping them on float is not going to be a problem. Is would charge from the grid since you have it, except when you exercise the genny.  Burning “cheap” propane is false economy imho.

    icarus



    $1.19/gallon delivered really is cheap propane. Available here in August and September with a large propane tank. I have about 1500 gallons. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    My point however is that burning it in a genny to charge batteries when the grid is available, is more likely than not to still be more expensive per KWH.  How many KWHs are you going to see out of a LP genny per gallon?  Compare that to the $$ per kwh of the grid and I’m guessing the grid is gong to be cheaper by about 1/2.
  • shawnj72
    shawnj72 Registered Users Posts: 64 ✭✭
    Thanks for the comments. This year Propane was $.89 cheapest Ive seen in a lifetime.. Sometimes you don't go for the cheapest but other reasons to pay someone else. I wont do my Utility any Favors if I don't have to as they go out of their way not to do me any. Kind of a grudge per say. They are trying what a few others have succeeded as trying to Tax you for having solar and generating your own power.  Which is another subject all together a sore one IMHO. But want to clarify what is best for the Battery Bank as it was Probably the Most expensive investment and i like to get the most of everything if possible. I will continue to leave it on float from grid power and Cycle them at least once a month here in the winter months.. The summer I plan to cut (Not Literally but sure would like to ) the main and see what i can do to not give the Utility one cent if possible.. I'm sure ill get the non compliant surcharge for under usage..which is 25 or 50 bucks a month.. But it was intended for backup purposes and supplement. Wasn't really intended for complete off grid as i believe it is about half of what i would need and the winter months it would be pretty tough and some better technology and wind power would be needed to even think about it.. Or shave the power consumption drastically. But Power hungry wife and 6 kids that believe everything needs to be plugged in and shining bright it would be a constant battle i would be sure to loose all sanity trying to change..But i will say this they didn't think i was insane when we were the only one for miles with light on during the outage.. They did come to appreciate the hard work.. Thanks a bunch for the reply and ill keep doing what I am doing and see what happens i suppose.. Thanks Again.. Shawn     
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited December 2019 #9
    Count yourself lucky, I have 10 young kids, under 2 weeks old, all from different mothers of course, which all need to be kept warm and fed when temperatures are unusually low as they are currently, luckily they sleep through the night without a whimper once fed before sleep time.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    10 kids under 2 weeks old?  Yikes.  Had twins, and they took turns waking us up!
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    FWIW, and just my opinion, discharge cycling isn't needed to stir electrolyte.  A periodic (eg monthly) absorb cycle should be sufficient.  Water and SG should also be checked, and EQ done if needed.  My 5yr old L16s have been lasting the winter mostly floating with periodic absorbs without added water, but I think forklift types tend to use more.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    "Kids" = Baby Goats?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Must be.  I can't imagine 10 human babies other than in a maternity ward.  We must be about the most needy and helpless infants in creation.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    edited December 2019 #14
    Estragon said:
    Must be.  I can't imagine 10 human babies other than in a maternity ward.  We must be about the most needy and helpless infants in creation.
    Our environment differs. One minute video to drive home the message: https://www.youtube.com/watch?v=e1vJQyV8lMI


    By comparison, we get 18-22 years to prepare for that lion, I mean the government. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    BB. said:
    "Kids" = Baby Goats?

    -Bill
    Yes goats, the temperature lately has droped to 5°C, usually the minimum is ~20°C, the kids would get crushed by the adults as they huddle together to keep warm, so I have to bring them indoors overnight.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • shawnj72
    shawnj72 Registered Users Posts: 64 ✭✭
    Estragon Thanks for the info.. so IYHO just a couple week or monthly Absorb charge is all that is needed not leaving it on float 24-7 or cycling using them once a month to keep them exercised ..  sometime I think taking care of 10 farm kids would of been easier thats for sure..
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    -20C!!??  I thought you were in Thailand McGivor?  Climate change or what?
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    shawnj72 said:
    Estragon Thanks for the info.. so IYHO just a couple week or monthly Absorb charge is all that is needed not leaving it on float 24-7 or cycling using them once a month to keep them exercised ..  sometime I think taking care of 10 farm kids would of been easier thats for sure..
    Cool batteries have a much lower self discharge rate. I charge stored batteries every month during the summer, much less during the winter. Though I do live in a cold climate. Right now the stored batteries are sitting at ~ 39F. Their summer temp is very low 60s. 

    Probably why I get a few more years out of my batteries as a rule. I'm finally pulling a 2011 8D out of service next week. I did lose a batch of 8Ds due to sulfation when I ignorantly ran them below 12 volts all winter - my first winter with an inferior solar bank. 


    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Mcgivor is using the wavy line "~" for approximate... It can be missed as the minus  sign/dash "-"... So, I think +20C is his minimum.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    As softdown notes, self-consumption and sulfation will happen more slowly at cooler temps.  If they're somewhere cold and are fully charged, just leaving them alone (disconnected) for a couple of months isn't a terrible idea.  Fully charged, they won't freeze in any temps you'd see.  I disconnect my boat batteries in an even colder climate and let them sit for winter.  Do be sure to turn off and disconnect any connected devices (eg inverters, charge controllers, etc) though to prevent them slowly discharging the bank.

    If they're somewhere warm, I'd likely float them and do an absorb (eg) monthly.  Depending on how warm, you could probably get away with just a regular absorb cycle.  The float just basically offsets whatever self-discharge is happening.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • shawnj72
    shawnj72 Registered Users Posts: 64 ✭✭
    Thanks again for the input.. These will be between 65 and 75 degrees year around..so no real extreme swings either way.. 
  • KenMorgan
    KenMorgan Registered Users Posts: 92 ✭✭
    Estragon said:
    Must be.  I can't imagine 10 human babies other than in a maternity ward.  We must be about the most needy and helpless infants in creation.
    Mcgivor does live in Thailand so you never know  ;)  



    30kw LiFePo4 battery bank, 18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    KenMorgan said:
    Estragon said:
    Must be.  I can't imagine 10 human babies other than in a maternity ward.  We must be about the most needy and helpless infants in creation.
    Mcgivor does live in Thailand so you never know  ;)  



    Goat kids! Don't know what you are thinking,, but ....never mind
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.