What is proper dod at -1c

just starting
just starting Registered Users Posts: 235 ✭✭✭
in Off Grid Solar & Battery Systems #1
I have 6 250w panels a 60-150 894ah agm bank its staying between -3 and 1 c and in the morning the Volts on the cc say 25.2 on avg and once 25 v am I OK
200ah LiFePO4 24v Electrodacus Sbms40 quad breaker chest freezer to fridge- Samlex PST 1524 - Samlex pst3024  - 1hp shallow well pump-Marey 4.3 GPM on demand waterheater - mama bear Fisher wood burning stove, 30" fridgarair oven ,fridegaire dishwasher  Unique 290l stainless D.C. Fridge-unique 120l portable fridge/freezer 
· Share on Twitter

Comments

  • just starting
    just starting Registered Users Posts: 235 ✭✭✭
    #2
    Also I built a insulated box that has r 13 fiberglass and 2" foam in the box I can run some PVC and a small 24 v fan would it be worth heating up the battery's for power gain
    200ah LiFePO4 24v Electrodacus Sbms40 quad breaker chest freezer to fridge- Samlex PST 1524 - Samlex pst3024  - 1hp shallow well pump-Marey 4.3 GPM on demand waterheater - mama bear Fisher wood burning stove, 30" fridgarair oven ,fridegaire dishwasher  Unique 290l stainless D.C. Fridge-unique 120l portable fridge/freezer 
    · Share on Twitter
  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    #3
    We dont get those sort of temps here, but as far as i know thats not too cold for a charged lead bank.  25V is fine. 24V then youre low.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


    · Share on Twitter
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #4
    Be careful how you interpret the voltages you read on the CC, especially if the CC has a remote temperature sensor for battery temperature.
    The charging settings need to be adjusted to match the actual battery temperature, but some CC manufacturers have chosen (to avoid confusing casual users?) to display the "corrected" measured voltage rather than displaying the real voltage and changing the set points.
    SMA SB 3000, old BP panels.
    · Share on Twitter
  • just starting
    just starting Registered Users Posts: 235 ✭✭✭
    #5
    It does have a temp sensor my cc is a xantrex 60-150 mppt I'll check with a volt meter
    200ah LiFePO4 24v Electrodacus Sbms40 quad breaker chest freezer to fridge- Samlex PST 1524 - Samlex pst3024  - 1hp shallow well pump-Marey 4.3 GPM on demand waterheater - mama bear Fisher wood burning stove, 30" fridgarair oven ,fridegaire dishwasher  Unique 290l stainless D.C. Fridge-unique 120l portable fridge/freezer 
    · Share on Twitter
  • CALLD
    CALLD Solar Expert Posts: 230 ✭✭
    #6
    25v under load indicates a high state of charge (above 80% SOC), 25v resting voltage indicates a partial state of charge. A fully charged AGM battery (at rest) should read closer to 26v even at a temp of -1°C
    · Share on Twitter
  • softdown
    softdown Solar Expert Posts: 3,896 ✭✭✭✭
    #7
    Surprised that this question has been unanswered by the more knowledgeable here. I don't think heating them is a good idea unless you can do it with the sun....which would produce warm daytime batteries and cold night time batteries. Batteries last a lot longer when they are kept in a cool environment. Canadians may think they are better at battery management because their batteries last longer up north.


    ust starting said:
    Also I built a insulated box that has r 13 fiberglass and 2" foam in the box I can run some PVC and a small 24 v fan would it be worth heating up the battery's for power gain

    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
    · Share on Twitter
  • just starting
    just starting Registered Users Posts: 235 ✭✭✭
    #8
    At 3 am my bank is at -6c and 24.7 underload I will shutoff inverter for a few hours and check bat voltage
    200ah LiFePO4 24v Electrodacus Sbms40 quad breaker chest freezer to fridge- Samlex PST 1524 - Samlex pst3024  - 1hp shallow well pump-Marey 4.3 GPM on demand waterheater - mama bear Fisher wood burning stove, 30" fridgarair oven ,fridegaire dishwasher  Unique 290l stainless D.C. Fridge-unique 120l portable fridge/freezer 
    · Share on Twitter
  • just starting
    just starting Registered Users Posts: 235 ✭✭✭
    #9
    Thanks for the responses
    200ah LiFePO4 24v Electrodacus Sbms40 quad breaker chest freezer to fridge- Samlex PST 1524 - Samlex pst3024  - 1hp shallow well pump-Marey 4.3 GPM on demand waterheater - mama bear Fisher wood burning stove, 30" fridgarair oven ,fridegaire dishwasher  Unique 290l stainless D.C. Fridge-unique 120l portable fridge/freezer 
    · Share on Twitter

Categories