How do you keep your deep cell batteries warm?

90cummins90cummins Solar Expert Posts: 57 ✭✭
My newly installed Xantrex 4024 inverter and backup batteries are in my unheated garage. The batteries (L16RE-B) are close to the inverter to minimize voltage drop and are in an insulated 3/4" plywood box with small vents.
They are currently at 44 degrees and we are not into the cold weather yet.
According to Trojan they lose 10% capacity for every 15deg below 80deg. Does anyone have a suggestion on how to safely keep them warm????

Thanks 90cummins

Comments

  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: How do you keep your deep cell batteries warm?

    Welcome to the forum "90cummins"
    Some of us use an insulated battery box. I sometimes insulate my battery box, other Winters I get lazy and don't. The act of charging generates heat within the batteries, thus warming them. Where I live we do have some stretches of minus 20C and colder weather. Insulated, my batteries rarely drop below 0C. Uninsulated, they sometimes drop to minus 6, 7 or 8C. And that's in an unheated, uninsulated, outside shed. Since I don't regularly drain by batteries below the 80% fully charged state, I notice very little difference other than somewhat lower voltage under load, and of course higher voltage while being charged.
    Cold batteries are a two sided issue. yes, their capacity drops somewhat when they're really cold, but on the other hand, their lives are extended when colder.
    I'll accept slightly lower voltage for longer battery life, they're expensive to replace. At the moment mine (uninsulated so far) are at 8C (46F) and Winter is yet to come.
    My opinion, unless you plan on really draining your batteries down in a way that requires all the capacity you can get out of them, don't fret about them getting cold, they won't freeze unless they are allowed to get discharged too low.
    What are your "normal" Winter temps?
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: How do you keep your deep cell batteries warm?

    It's been in the 20's but it's early, it will get into the single digits and below -0- DegF..
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: How do you keep your deep cell batteries warm?

    Location Florida Ma

    Your where ?? it will get into the single digits and below -0- DegF..

    Don't waste SCOTCH , it won't freeze till -20c


    VT

    EDIT ADD !! Florida, Really ?? USA Needs to not have 35+ Springfield towns , when i read this location /I floored myself ,till i googled MA .
    https://www.google.com/maps/place/Florida,+MA/@42.6604264,-72.9868939,12z/data=!4m2!3m1!1s0x89e0c5f0e14d7c61:0x3ad298d654368f9d

    My ideas are in test , & on the mountains our temps are the same.

    VT
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: How do you keep your deep cell batteries warm?

    Yup; Florida Massachusetts's on the top of the mountain with 6.3kw of solar and excellent exposure.
    Battery backup was added to utilize my solar in event of a prolonged outage which is in addition to my gas and diesel generators.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: How do you keep your deep cell batteries warm?
    90cummins wrote: »
    Yup; Florida Massachusetts's on the top of the mountain with 6.3kw of solar and excellent exposure.
    Battery backup was added to utilize my solar in event of a prolonged outage which is in addition to my gas and diesel generators.

    So basically your batteries are being kept charged, but sitting unused for long periods of time while waiting for a power outage?
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: How do you keep your deep cell batteries warm?

    Yes currently they are sitting in float mode.
    This weekend I'm planning to go on battery backup to see how long they will support my basic .7kw to 1kw base load.
    I'll see if that warms them up.

    90cummins
  • peakbaggerpeakbagger Solar Expert Posts: 341 ✭✭✭
    Re: How do you keep your deep cell batteries warm?

    Buy yourself a USB data temp data logger and run it through a winter, then decide based on data.
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: How do you keep your deep cell batteries warm?

    My Xantrex inverter has a battery temperature sensor attached to a battery post and the temp is currently around 46deg F.
Sign In or Register to comment.