Snow is coming

wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
Hi all , the snow is coming , how do I manage my system over winter .
 I plan to leave the inverter off but the rest of the system uses power if the panels get snow covered the battery could be depleated . 
 I plan on working up at the house every other week end ,but could get snowed out . 
 Could I leave my LA battery’s @ full charge and just turn off the system ? 
 I could charge with my genarator when I’m there . 
  How long can they sit with out damage . 
Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .

Comments

  • mcgivormcgivor Posts: 2,321Solar Expert ✭✭✭✭✭
    Hibernation is what the animals do, batteries become less active in the cold, turn everything off and let them hibernate, less to worry about, there are charts for various chemistries and their self discharge with relation to temperature, most/all are inactive in the cold.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    Thanks mcgivor , how long could the battery’s sit with out charge . 
     I’m sure it will be @ freezing in the battery box . 
     I have  16 golf cart battery’s 
     I’m sure I’ll be ok for a few more weeks but the time is coming 

    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • mcgivormcgivor Posts: 2,321Solar Expert ✭✭✭✭✭
    Just make sure they are fully charged before storage and refresh charge when possible or after hibernation, you didn't mention FLA or AGM, perhaps a good time to create a signature so we don't have to guess or assume  :)
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

  • EstragonEstragon Posts: 2,952Registered Users ✭✭✭✭✭
    A fully charged L.A.  battery is okay to ~ -75°f.  With zero load in freezing temps, they'll self-discharge very little, and should last until spring.  My boat bank does fine, and temps can get into the -40s.  Some years I give them a top up mid-winter, but they're still okay even if I don't.

    At the cabin, I leave the charge controllers on though.  Although small, they are still a load, and will drain batteries to a point where they could freeze in a matter of weeks if panels get covered.  I ended up adding some panels mounted vertically to ensure there will be enough to offset CC load if the big arrays get covered.  The alternative would be to turn them off.
    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. Posts: 28,079Super Moderators, Administrators admin
    edited November 9 #6
    More or less, the starting estimate is the engineering rule of 10C 1/2 or 2x change in life... And self discharge.

    Say a FLA battery needs to be recharged every 1 month due to self discharge (going from ~100% to 75% State of Charge is "normal storage" range) at 25C (77F). And your batteries are at -5C (23F) or lower during the off season... That is 30C / 10C = 3x groups of "2" (or 1/2).

    1/2 * 1/2 * 1/2 = 1/8 slower discharge (longer life)... 1 month * 8 factor for cold temperature = ~8 months between recharging and self discharge (when at -5C or lower storage temperature). As long as the batteries start at ~100% SoC when you put them down for winter.

    If you choose to run a solar panel/array during winter with a solar charge controller--You can do that too. Mounting panels high and near vertical (if you have drifting snow), or a couple panels on the side of the building with a smaller charge controller (PWM if "12 volt panels", MPPT if needed)--Using a larger charge controller (the Midnite Classic, Outbacks, etc. that are >60 amp MPPT controllers, Ethernet remote comm, etc.)--You run the risk of snow blocked panels and the controllers discharging the battery bank over the multiple months of controller load without sun killing your battery bank. Smaller MPPT controllers (no ethernet connections, simple PWM controllers) have lower self discharge.

    For example, Midnite is nice enough to give us the standby consumption of 2.5 Watts per MPPT charge controller (Outback FM 80 is <1 Watt):

    https://www.solar-electric.com/lib/wind-sun/Classic-specifications.pdf
    https://www.solar-electric.com/outback-power-flexmax-fm80-150-mppt-charge-controller.html
    • 2.5 Watts * 24 hours per day * 12 weeks of winter = 720 WH per "winter"
    • 720 WH / 12 volts = 60 AH of discharge current @ 12 volts
    And any other loads you may have (cell phone alarm system, battery monitoring system, etc.). And make sure that no inverters (or other unneeded loads) are accidentally powered up (or even on standby)... On standby a "full size inverter" may draw 6 Watts on standby and 10-20-40+ Watts on with no loads.

    Also, you want to make sure that the controller stays in float charge (low voltage charging)...You don't want the controller to go into absorb state charging very much during the off season--Nobody there to watch the water usage.

    And watch "new installations"... You don't want to set up your new "winter float" system the day before you leave--You want to have it working and monitor it for at least a few days to make sure it is doing what you want.

    From what I have read here... It is 75F for a high today, and we get "snow" every 20+ years that goes away in a few hours. Not the cold weather expert.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    I will leave the inverter off and solar charger on for now and watch what’s happening . 
     I should be up there every 2 weeks . 
     If the out back fm 80 uses 1 watt 24 watts a day that’s not to bad .
     I’m hope the panels will be clear of snow , time will tell . 
     At the point the panels get snow covered I will charge up to full and leave the system off . 
      I could snow shoe in to check things out . 
     Or maybe keep the place plowed  I get a lot of snow up there  thanks for the Quick response
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    Has any one use one of these ? I was trying to get my battery’s ready for winter . My system was put in service 10 weeks ago .
     My 2 strings of battery’s where very close to full charge and I figured the 2 strings of 8 gc230 ah battery’s would grow closer once they where being charged together.  (Wrong)  both strings where kind of all over the place .
     10 battery’s where about 1.275 the rest where 1.265 1.55 one was 1.230 seam like a big spread for 10 weeks of weekends and low usage  the system sits on float for 4 days a week ? It was 50o in the battery box I did not bother adjusting the numbers ? 
     The easy red gives me good reading  just above 1.275  on all the battery’s , the other hydromader is all over the place
     some where 1275 as a high to a low of 1230+-  the easy red reads water a little higher and I figure that is why I’m over on the full charge reading 1280/1285  how do I tell if the  hydrometers are  accurate . 
     My absorb is 59.2  for 3 hours. I pushed it to 31/2 hrs float 54  for between 11/2/31/2 hrs  A day 
      I did not have time to EQ and the sun was going down     What do I need to do ?      Thanks in advance john
    .
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • EstragonEstragon Posts: 2,952Registered Users ✭✭✭✭✭
    I had lots of trouble reading my glass float type meter.  Even with repeated rinsing, it often stuck instead of rising to an accurate read level, so it often took 4 or more reads/cell to get a decent sense of things.

    I switched to:
    https://www.solar-electric.com/midnite-solar-battery-hydrometer.html

    It still needs rinsing, and sticks occasionally, but way less than the glass one.
    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
  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    Thanks estragon , just bought one from amozan 
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • westbranchwestbranch Posts: 5,099Solar Expert ✭✭✭✭
    Since they are new batteries, it will help you if you record the SG values for each cell, then you have a base line of the starting  SG's and also record the voltage of each battery...  with all those batteries you will have a head full of ' now what was that SG??' running through your head.
    I use the 2 PV's vertical on an outside wall as a safety net now  just in case, we were pushed to get out before we got snowed in, a few years back, and when we got back 2 months later, the CC was still on but the batteries lost a few years of life at a minimum!
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    My system was put into service 9/10 weeks a go and all the battery’s where close 1275 1270 I thought they would grow together once combined in the system . 
     I seam to have a hard tome reading SG the easy red reads good ( maybe all the time ) the other on is all over .
     It seams like it’s sticking but I did rinse it with distilled water every time I used it . 
     I bought a new hydromador mid night solar battery hydromitor  and see how it works.
       I will start keeping a log starting this weekend . 
     My solar panel are getting covered in snow now ,  hopefully it melts off .
       I dont  really have a good spot for Vertical panels to sit in the sun now , im treed in till next year . 
        I plan on working there thru the winter if I can get in . So I was thinking I would just turn the system off when I leave 
       I could snow shoe in if I have to and top up the battery’s . 
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • EstragonEstragon Posts: 2,952Registered Users ✭✭✭✭✭

    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
  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    Wow that is a great spot. 
     That’s  the type of property I wanted,  but any thing with water is just so far out of my reach  financially . 
      Taxes here on a piece of land like that would be 30k a year .
      We have a place in lake George ny , 2 blocks from a 500’ beach area taxes are4500 a year slide that house to the water and the taxes jump 4.5 times about 22 k plus  , all the old timers had to sell out and head to the reast home , I didn’t want to be one of them I’m in the Mountains
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • EstragonEstragon Posts: 2,952Registered Users ✭✭✭✭✭
    Taxes are ~$1500CAD/yr (for zero services, mind you).  The snowshoe hike is ~3mi, mostly across ice, with a short portage.  Not sure I could hack it in the mountains.

    Nearest neighbours are near the cleared bit past the points to the left of the snowshoe trail, a bit over a mile away.  Very quiet, especially in winter :smile:
    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
  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    edited November 17 #16
    Very nice , who need services anyway , in ny the towns don’t do much to help you , no water or sewer no trash pickup  there are police but they are not really a help in my eyes any way. 
     If I was sick I can’t call out most of the time  I can text and it will go thru  eventually but I can’t text a 911. 
    Im at the top of a 2 1/2 mile long Mountain Road  with six houses and two full-time residences.
     We had a 16 ‘ snow drift across the road  that the town pushed off with a cat loader , I get the same drift across my driveway . 
     I’m hoping I can handle the  mountains as age .
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • mcgivormcgivor Posts: 2,321Solar Expert ✭✭✭✭✭
    Property taxes drove me out of Canada, Vancouver in particular, the changing demographics fueled by offshore buyers were responsible for the upward trend of property values, this however resulted in increased property taxes. Starting in 2000 when I purchased taxes were $710 per annum on  a property valued at $165 000, by 2015 the taxes were $3700 value $890 000, so sold and decided to move as my income was not proportional to the rate of increase.  Now with 15 Acres in Thailand my annual tax is $6, no services, none expected, Ironically the value here has also increased ten fold in ten years but the taxes  remain constant. Go figure.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

  • wellbuiltwellbuilt Posts: 321Solar Expert ✭✭✭
    6 bucks is really good😋 I’m going to try to stick it out  here in NY , my wife is ageing in dog years .
     She is liking assisted living but that’s not for me . 
     I’m pushing 60 now  I’ve gotten old the last few years . 
      There is a lot of work to do  living in the mountains in the middle of nowhere  I hope in up for it 😎
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • westbranchwestbranch Posts: 5,099Solar Expert ✭✭✭✭
    edited 2:19AM #19
    Just make sure you get 90% oft the heavy stuff done before you have open heart work done, it takes about 2 years before you 'feel' almost normal,  like you did before the operation... :) :) :
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • softdownsoftdown Posts: 1,928Solar Expert ✭✭✭✭
    Epic thread drift. Pretty good at it myself but feeling completely outclassed at the moment.
    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
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