Volt thermal management system temperature band?
Grab our Forum Feed

+ Reply to Thread
Page 13 of 18 FirstFirst 1 3 13 18 LastLast
Results 121 to 130 of 177

Thread: Volt thermal management system temperature band?

  1. #121
    Join Date
    Jul 2010
    Location
    Atlanta GA
    Posts
    1,153

    Default

    So, an increasingly common question around here is something like:

    "It's 13 degrees outside, is my battery OK?"

    With this post, I'm going to try to capture the temperature thresholds where the different modes kick in. This data is NOT official! It's just what I've gathered from reading various sources.

    It's important to note up front that we are talking about the temperature of the battery pack here, not ambient temperature. It's a 400 pound battery pack, well insulated, so it is going to take a long time to cool down / warm up to whatever the ambient temp is. An overnight park, even in a mode where the TMS isn't kicking in, is not necessarily long enough to get the pack to ambient. So an overnight low of -13 F doesn't mean the battery pack itself will actually cool down to that cold!

    Code:
    Volt battery temperature management system (TMS) modes
    
    Temperature range   | Volt is parked       | Volt is parked       | Volt is powered on
                        |  and plugged in      |  but NOT plugged in  |  (e.g. being driven)
    --------------------|----------------------|----------------------|----------------------
                        |                      |                      |
    above 122 F         | cooling(1)           | cooling(1)           | car won't run until battery
                        |                      |                      | is cooled below 122 F by TMS(2)
                        |                      |                      |
    122 F .. 86 F       | cooling(1)           | cooling(1)           | cooling(2)
                        |                      |                      |
     86 F .. 72 F       | cooling(1)           |                      | cooling(2)
                        |                      |                      |
     72 F .. 68 F       | no action -- ideal temperature band for long-term life
                        |                      |                      |
     68 F .. 25 F       |                      |                      |
                        |                      |                      |
     25 F .. 14 F       | warming              |                      | warming(3)
                        |                      |                      |
     14 F .. -13 F      | warming              |                      | warming(3)
                        |                      |                      |
    below -13 F         | warming              |                      | car won't run until battery
                        |                      |                      | is warmed above -13 F by TMS(3)
    
    * Notes:
    (1) High temperature cooling will only run if the SOC is >75%.  If the SOC is <75% then there is no action.
    (2) At extreme high temps, the ICE may come on to generate power for the TMS to work faster,
      but only if the car is powered on (that is, the ICE won't start by itself, unmanned)
    (3) At low temps, the ICE may come on to generate power for the TMS to work faster, and to generate
      power for the cabin heater, but only if the car is powered on (that is, the ICE won't start by itself; it will
      only start once the car is powered on or it receives a remote-start command);  the ICE will shut off once
      it reaches 150 F.  Note that the ICE coolant can not be used to directly heat the battery because the
      battery coolant loop is separate.
    The above is for regular operation. If you are putting the Volt into storage for an extended period, without plugging it in, the manual says (on page 10-25) that ideally you should store it where the temperature range will be within 14° F .. 86° F. Traction battery SOC should be at 50%, and the 12 volt battery should be disconnected or on a trickle charger. Note that this is for long-term storage, not just parking it for a few days or even weeks.

    The data I have in here now is what I gathered from reading back a few pages in this thread, including that digested from Charles Whalen's post here last month, WOT's front page article and comments last Thursday, and whatever further comments I can get.

    WOT and others, can you help clarify this further? You can just describe the behavior in plain text, and I'll figure out how to fit it in above (adjusting temperature ranges accordingly). It seems like the low temperature operation is what is most unknown here.
    Last edited by ChrisC; 01-17-2011 at 12:08 AM.
    2011 Volt #284, ordered 30-Jul-2010, built 30-Nov-2010, shipped 15-Dec-2010, delivery 22-Dec-2010, lease return 22-Dec-2013, www.FirstVoltInGeorgia.com
    - The FAQ -- answers to your Frequently Asked Questions about the Volt
    - how to track your Volt order, meaning of status codes, railcar tracking
    - do yourself a favor and register at VoltStats immediately so you can track your Volt's performance

  2. #122
    Join Date
    Oct 2010
    Posts
    209

    Default

    I am getting more confused. So if i leave my car out on a 100 degree day after depleting the batteries by 50% by getting to work and the inside of the car heats up to 130 degrees what do I do to get the temperature down? Can I even start the car? Can I get the electronics to operate to open the windows or do I just have to open the doors lmao? If I can't start the car to get the combustion engine to run for AC then how am I supposed to cool the car down if I am no where near a plug? Same goes for when it is -20 outside all day. Am I not supposed to drive or let the car sit out during these temperatures for 8 hours? Maybe you are saying I can start the car to run the ICE but I have to wait for the car to cool/heat in order to drive???

    Thanks
    P

  3. #123
    Join Date
    Sep 2010
    Location
    San Diego, CA. VIN B-95
    Posts
    2,632

    Default

    Quote Originally Posted by cheifsfan View Post
    So if i leave my car out on a 100 degree day after depleting the batteries by 50% by getting to work and the inside of the car heats up to 130 degrees what do I do to get the temperature down? Can I even start the car?
    It's my understanding that the battery is pretty well insulated. I think the way it works is an 8 hour soak isn't enough to bring the battery out of operating temperature range. The battery is probably significantly better insulated than the interior of your car. The car may get really hot as far as you're concerned, not so much for the battery.

    Same goes for when it is -20 outside all day. Am I not supposed to drive or let the car sit out during these temperatures for 8 hours?
    Same here, but if you're going to leave it out in the cold a *long* time you'd better have a block heater outlet. Just like you would with any other car. An ICE car doesn't do well in that environment either...

  4.  

    Advertisement

  5. #124
    Join Date
    Oct 2010
    Posts
    209

    Default

    Agreed about the insulation but what does happen when the batteries do get outside this temperature and how do you bring them back to within there operating temperatures...

  6. #125
    Join Date
    Sep 2010
    Location
    San Diego, CA. VIN B-95
    Posts
    2,632

    Default

    Quote Originally Posted by cheifsfan View Post
    how do you bring them back to within there operating temperatures...
    Plug the car in. If you don't have a plug handy, tow it to a plug and then plug it in.

  7. #126
    Join Date
    Oct 2010
    Posts
    209

    Default

    The car cannot even start without it coming back within range? ChrisC says it's not drivable but doesn't say you can't star the ice. That is a disappointment if you have to somehow get it plugged in, towed, or wait for the outdoor temperature to come back within range. I can't believe if I have 60% battery left and the batteries are close to going over 120 degrees it wouldn't try and cool down instead of creating a scenario where the car cannot be used at all and also allow the batteries to reach damaging temperatures

  8. #127
    Join Date
    Sep 2010
    Location
    San Diego, CA. VIN B-95
    Posts
    2,632

    Default

    Quote Originally Posted by cheifsfan View Post
    I can't believe if I have 60% battery left and the batteries are close to going over 120 degrees it wouldn't try and cool down instead of creating a scenario where the car cannot be used at all and also allow the batteries to reach damaging temperatures
    It's my understanding that if you have 60% SOC the battery CAN'T be out of its temp range. WOT (or anyone else who knows) can comment, but I believe it can always start the ICE hot. It's just a deep cold soak with battery < 50% that forces a plug in. And many places where that can happen have provisions for block heaters.

  9. #128
    Join Date
    Nov 2010
    Location
    Ottawa, Canada
    Posts
    488

    Default

    My concern is with the bottom of that scale. According to the manual, there is a minimal temperature below which the Volt will not start at all and needs to be plugged in to start (even the ICE as far as I can understand). It's critical for me to know what that temperature is, otherwise I could be stranded at work at the end of a day.

  10. #129
    Join Date
    Jul 2010
    Location
    Atlanta GA
    Posts
    1,153

    Default

    Indeed, therfman, it's recent concerns from folks like you that inspired me to start trying to make sense of this. We'll get to the bottom of it, pun not intended

  11.  

    Advertisement

  12. #130
    Join Date
    Feb 2008
    Location
    Rancho Palos Verdes, CA
    Posts
    692

    Default

    Quote Originally Posted by cheifsfan View Post
    I am getting more confused. So if i leave my car out on a 100 degree day after depleting the batteries by 50% by getting to work and the inside of the car heats up to 130 degrees what do I do to get the temperature down? Can I even start the car? Can I get the electronics to operate to open the windows or do I just have to open the doors lmao? If I can't start the car to get the combustion engine to run for AC then how am I supposed to cool the car down if I am no where near a plug? Same goes for when it is -20 outside all day. Am I not supposed to drive or let the car sit out during these temperatures for 8 hours? Maybe you are saying I can start the car to run the ICE but I have to wait for the car to cool/heat in order to drive???

    Thanks
    P
    No, no, no. When the Volt's battery is at the temperature extremes, you can still drive the car. However, rather than operating in EV mode (assuming the battery SOC is above the lower threshold), the ICE will come on and run the TMS to cool/heat the battery until the battery temp gets back to spec. Once the battery is back to temp spec, the Volt will revert back to EV mode (assuming the battery SOC is above the lower threshold). You will not be stranded.

+ Reply to Thread
Page 13 of 18 FirstFirst 1 3 13 18 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts