Model X

What's up with the cold battery limit?

edited November -1 in Model X
Last week it was pretty cold here in Orlando, and the dash indicated that regen had been limited to half. Why is this? The battery can still output the full 200 kW, and the normal 40 kW of regen seems like it significantly below what the battery should be able to handle ( superchargers can pump in 160 kW ), so why is it lowered even more when cold?

Also isn't it supposed to heat the battery up to fix this? It was still limited after my 30 minute drive to work.
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Comments

  • edited January 2018
    I am not sure on all the logistics as I am NO expert, but one thing I have learned from someone on the 3 forum, batteries in general can be damaged if they are charged while cold. So the output is less of an issue, but the input. Note that yes, even after 30 minutes of driving, especially if you keep the heat off, the battery still may not be warm enough to do full regen - all in the name of preserving battery degradation or significant damage. Supercharging the same thing can actually happen - ie if it is extremely cold/ battery is cold soaked, it takes a bit to ramp up the charging speed - my understanding is that the battery needs to warm up, but it does so much faster because you are supplying energy to the car that can in turn heat up the battery much faster than you just driving it around.

    Again, i am no expert, some are things I have gleaned from the forums from others. I am sure someone with more knowledge can pipe in and give you much better info that I :)
  • edited January 2018
    There you go. To @burdogg do you listen! (/yoda) Yes, permanent damage to lithium ion batteries from charging fast while they are cold.
    If only the manual said something about this. *hint hint*
  • edited November -1
    :) Yoda, it is so hard though, I just can't... I mean, have you read the forums lately, it is so hard to listen :)

    Manuals? Manuals! Are you trying to tell me I should read the manual? I don't read no stinken manuals.
  • edited November -1
    Oh and sorry - I just read my post and should have been more strong on the permanent damage to lithium ion batteries from charging while they are cold, as i did know that one :)
  • edited November -1
    Manual? I thought the thing was automatic. Shoot!
  • edited January 2018
    If you pre-heat the interior, will that heat up the battery before you try going out in the cold? I have read we should always pre-heat, but the only option I see on my app is the interior climate control. Am I missing something?
  • edited November -1
    You aren't missing anything - it is the interior climate control on the app. This will also heat the battery through natural use and heat. Now they supposedly updated the app to also pre-heat the actual battery when plugged in and there is supposedly a red battery icon right between the seats that shows the battery is being heated - I have yet to see it though, so don't know if it truly has been rolled out or not yet. But as far as I know, there is not an actual Pre-heat Battery button - it is just done by turning the interior heat on.
  • edited January 2018
    Also the best thing to do is to time your charging so it is finished as close to the time you leave as possible - this will give you much better wh/mi and full regen.
  • edited November -1
    Thanks bhoskins - I have yet to have that show up - is it only when you are plugged in and temps are certain degree? What is the situation that you have that show up? or does it show up all the time?
  • edited January 2018
    @burdogg: Same, same: I have yet to see the battery-is-being-heated icon, even when outside temps were single digit (garage doors insulated, two walls with exterior sides not), lthe X connected to charger, and interior heating turned on.
  • edited January 2018
    @burdogg battery preheat video

  • edited November -1
    It shows up on mine
  • edited January 2018
    @psusi Do you have range mode on? Range mode doesn’t heat up the battery with electricity and it takes a long time for the X to warm itself up without the electric heat.
  • edited January 2018
    Just here to re-iterate that the key thing is to have Range Mode turned off to allow for battery preheating. I finally got mine to preheat when I read in another forum posting to turn off Range Mode. The preheat icon on the phone app does not immediately show up, nor is it always on, so if you're not watching the app, you'll likely miss it. The battery preheat icon usually does not show for me until the cabin temperature had reached almost 50 degrees (a few times it has come on in the high 40s) It also seems to turn off when my cabin reaches 75 degrees, sometimes sooner. (I usually like to preheat to 76 or 77). The most preheating I've noticed is about 1/3 rd regen range, so don't expect full regen from preheating.
  • edited January 2018
    I work with li-po batteries and have never heard of "damage" from charging while cold. Only the internal impedance going up which in turn limits the maximum current both going in and out of the battery. If it can take 190 kW at normal temperature, I can't see a little cold cutting that nearly to 1/4th... unless it was below freezing maybe.

    I did have the cabin heat on and don't *think* I had range mode on, but good to know that affects it.
  • edited January 2018
    @psusi

    Li-PO batteries are a very different chemistry. They have some advantages, but energy- and power-density are not as good, IIRC.
  • edited January 2018
    Burrdog: even timing my charge to end when I leave in the morning does not give full regen. The one and only thing that gives me full regen is if the outside temp is above 10 C.
  • edited January 2018
    Vawlkus - you need to find somewhere warmer to charge your car :)
  • edited January 2018
    This is Canada burrdog, it doesn’t GET warmer. }B)
  • edited January 2018
    Guess that is why I get two r's - to emphasize the burrr, its cold here in Canada :)
  • edited January 2018
    Wait, I thought the Tesla batteries *are* lipo?
  • edited January 2018
    No, Li-Ion
  • edited November -1
    Interesting... that link says:

    In short, it means that so-called “lithium-polymer” batteries are almost exactly the same as lithium-ion batteries, but they are instead contained in a flexible polymer casing. It’s basically just a repackaged lithium-ion battery.

    Which is pretty much what I thought, despite what johnse said.
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