Model 3

My Supercharging speed has recently gotten slower, what happened?

This is only a discussion concerning cold weather related charging slowdowns. We have gotten a few posts recently about it so I thought I would attempt to address it in detail and hope that new users that have the question can find the information useful.

Ok, so you have recently noticed your supercharging speed slow down and wonder if there might be something wrong. Well chances are, there is nothing wrong with your car and it is due to cold weather effects and it is due to your battery being too cold. When it is too cold, the car limits charging speed to help protect the battery as Li-Ion batteries can be physically damaged if you attempt to charge them at too high a rate when they are too cold.

Charging a Li-Ion battery at 0 degrees C is bad, so as you approach 0C the car restricts the level of charging it can accept whether it be by actual charging, or regenerative braking. At 0C the car will not charge the battery at all until it warms it up first.

Now how can you determine whether this is what is affecting your car? There are a couple of things that you can see on your screen. See the image I posted here of my screen. https://imgur.com/y12MCEi

At the top circled in BLUE, is a snowflake icon. This icon tells you two things, first that your battery is cold. Second, that some of your battery capacity is not available to you until your battery warms up. Circled in RED is the power bar. This is what turns green on the left half when you let off the accelerator and start regenerating. As you can see in the picture the left side of the line is dashed(or is showing dots as we generally say). The more dots you have the less regeneration capability you have due to in this case, cold weather. The other time you can see dots here is when you start going above 90-95% SOC% (state of charge).

So if you see dots on the left side of the power bar, then you are either at a high SOC, and/or your battery is cold and it will have its charging rate restricted. The more dots, the more restricted.

So now you may be asking, how do I warm up the battery. There are multiple ways. You can ensure that your charging finishes close to when you will be leaving in the morning for example by using the scheduled departure function in the car.(there are caveats here concerning your requested SOC vs what you will actually have in the morning but I am not going to get into that here). You can also turn on your climate control from the app some time before you leave(how much time is needed is battery temperature dependent). You could repeatedly mash on the accelerator and let off until the dots go away but you might get motion sick. :) You can also route to a supercharger and the car will "precondition" the battery in route. This does not work very well but will do a bit in an AWD vehicle. Further discussion about preconditioning can be found here https://forums.tesla.com/discussion/170664/battery-heating-explained/p1 It was written last January but I think everything should still be valid even for the Model Y.

Now lets get into a little ScanMyTesla(SMT) detail on those dots for those who just love data!

The number of dots tells you how cold your battery temperature is right...but how cold is it? I used to have a partial chart but I trashed it after the recent UI update because....ahh nevermind... anyway. Using SMT I have the following data, so far.
1.5C - 19 dots
3.5C - 17
4.0C - 17
6.5C - 16
7.0C - 16
9.0C - 14
9.5C - 14
13.0C - 12
13.5C - 11
14.0C - 11
14.5C - 10
15.0C - 9
15.5C - 8 dots

Eventually I will fill this out fully as well as get multiple readings at each temperature/dot level as I did originally. I am sure a lot of people would also like to see a charging level vs temp at multiple x-Temperatures but that would take a long time for me to do and is a lot of work.

Anyway, I hope this helped those new and old.
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Comments

  • Great work. Thank you for trying to help.
  • Unfortunately few if any will do a search to find this thread, and just open up another new topic.
  • > @gmr6415 said:
    > Unfortunately few if any will do a search to find this thread, and just open up another new topic.

    If it keeps getting bumped up then maybe some people will see it before they post a new thread. Who knows!
  • > @derotam said:
    > > @gmr6415 said:
    > > Unfortunately few if any will do a search to find this thread, and just open up another new topic.
    >
    > If it keeps getting bumped up then maybe some people will see it before they post a new thread. Who knows!

    Exactly why I commented. It seems to be a common topic lately.
  • @derotam, just make sure to bump it like I do with my thread about maximizing range.
  • > @WW_Icefree said:
    > @derotam, just make sure to bump it like I do with my thread about maximizing range.

    or your thread about banning fish?
  • I definitely made this mistake my first winter with the car in a trip to Duluth. Important piece to understand.
  • great article on maximizing range. @derotam Do you also study the charging level. I was getting a peak charge of about 260 miles. In the last two months it goes only to 244 with no seeings changed. Any thoughts
  • > @"jay.pearlman_98328346" said:
    > great article on maximizing range. @derotam Do you also study the charging level. I was getting a peak charge of about 260 miles. In the last two months it goes only to 244 with no seeings changed. Any thoughts
    >

    That is a whole other discussion and has to do with the BMS calibration. Quick and dirty on that is let the car sleep(no sentry, no summon standby) overnight at multiple SOC%(charge levels). This will still take a while to work, if it works at all.
  • @"jay.pearlman_98328346" here is a BMS recalibration reference. https://teslamotorsclub.com/tmc/threads/how-i-recovered-half-of-my-batterys-lost-capacity.204712/?utm_content=iss291&utm_campaign=ed9&utm_source=threadloom&utm_medium=email#post-4946309
  • edited January 16
    You really won't hit maximum charger speed when charging is something to be aware of.

    Got to work with 42 miles left. 10 hours later, car says 8 miles left. Off to new 250kW Tesla charger where, with 2/12 other cars charging, I get a max charge of 152 kW.

    Note that Projected Range had 8 miles while Rated Range says "9%" which would be 28 miles of original rated range of 310 miles or 26 miles on 2 yr/40k older battery of 290 mile capacity when actual range is 8 miles.

    Have to watch your Projected Range in Energy/Consumption.

    So "slow" charging in the norm even on fast chargers.

    9% - 90%
    Used: 60.82 kWh
    Added: 63.43 kWh
    Efficiency 100%
    Avg Voltage: 391.92V
    Max Voltage: - 402.00V
    Avg Amps: 181.54A
    Max Amps: 380.43A
  • More nonsense from dumb Troll
  • Yep...cold weather effects as discussed.
  • > @derotam said: > Yep...cold weather effects as discussed."

    Cold weather, it was 55F, should not affect charging if Battery Preconditioning works so cold is usually not a factor and at 55F and Preconditioned, no factor at all.
  • Just goes to show, again, that Fishev who hates his car and can't wait to get rid of it, doesn't know what he's talking about.
  • 152kW is slow Mr. Chademo?
  • > @FISHEV said:

    > Used: 60.82 kWh
    > Added: 63.43 kWh
    > Efficiency 100%

    The Tesla reporting 100% efficiency was interesting since it reported sending 60.82kWh to car but car "received" 63.43kWh.
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