Koolio46
Member
100% agree.
Recently, I read on the Y subreddit where someone was complaining / asking why they only got 50kW at a SC...I asked if he was at an urban SC and it turns out he was (maxes at 72kW).
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Model Y Supercharger V3 kW Speeds in Cold weather
- Thread starter TimothyHW3
- Start date
Recently, I read on the Y subreddit where someone was complaining / asking why they only got 50kW at a SC...I asked if he was at an urban SC and it turns out he was (maxes at 72kW).
Koolio46
Member
Interesting...btw, I’ve also heard the ‘thunk’ sound supercharging once when it was around 40F ambient temps. At first I was hoping something wasn’t wrong. Haha.
Great video. Could you please describe what you did before charging? How long did you drive the car, at what speeds etc. how long was it standing the cold before that?
Also, do you have other videos from later on, let's say at 40% and 60% and maybe 70%?
Thank you!
The car was parked overnight in our garage. Before leaving the house, I preconditioned the cabin using the defrost option a little less than an hour prior to leaving. I then navigated to the supercharger to initiate the battery preconditioning and went on my way. The total distance to the SC was 50 miles and it took about an hour to arrive traveling at 70-80 mph on the freeway.
I don't have any other videos unfortunately, but I did take pictures of the screen throughout the charge.. here are the results.
10:01 14% - 132 kW
10:02 15% - 147 kW
10:02 16% - 180 kW
10:02 17% - 187 kW
10:03 18% - 175 kW
10:03 19% - 171 kW
10:03 20% - 167 kW
10:04 22% - 161 kW
10:06 27% - 148 kW
10:13 47% - 109 kW
10:16 53% - 101 kW
69% - 75 kW
77% - 55 kW
I don't have any other videos unfortunately, but I did take pictures of the screen throughout the charge.. here are the results.
10:01 14% - 132 kW
10:02 15% - 147 kW
10:02 16% - 180 kW
10:02 17% - 187 kW
10:03 18% - 175 kW
10:03 19% - 171 kW
10:03 20% - 167 kW
10:04 22% - 161 kW
10:06 27% - 148 kW
10:13 47% - 109 kW
10:16 53% - 101 kW
69% - 75 kW
77% - 55 kW
The tapering when getting close to 50% seems normal. The fact you didn't reach ~250kW makes me think the battery still wasn't hot enough. I think the cabin preconditioning will stop heating the battery when it's around 20C (72F) so that's the temp when you leave home. I don't remember the precise number. While driving, the ambient air is cooling the battery and motors don't get very hot. Yes, navigating to the SC helps as one of your motors (the front) can be heated up when you don't use it to propel the car. Still, it doesn't generate that much extra heat in the battery. For a scenario like battery = 10C, outside ~0C, even if the front motor gets to 65-70C the coolant only enters the battery around ~16-17C... I'm going from memory, these are not very precise numbers, but you get the point. The battery doesn't heat up that fast either, it's a big mass. The battery might need 40C or even 50C to get full power. I wonder if someone has posted that information somewhere...
Provided Tesla still uses front stator for preheating on heat pumped 3s and Ys. Maybe they use the octovalve.
His charge curve is still better than one 3 with heat pump in another video, but I think this is a software issue with some lemon LG batteries Tesla used for 21 refresh
@silverstoned83
Did you hear a high pitched whining noise from the front when precondition started? And if yes did it stop after the prec. Msg disappeared?
I noticed the high pitch noise before I left the house when I started the navigation to the supercharger. I believe the noise was being created by the motors generating heat. Not sure if it was just the front, or both.
Also, during the charging session, the heat pump wasn't running at full bore like the first time I tried supercharging at low temperatures, which sounded like an outboard motor from inside the cabin. This time, the heat pump was barely audible, which again tells me that the battery temp was already satisfied for supercharging. This leads me to believe that the charging algorithm is dependent on outside air temp, not just battery temp, which is why 250kw was never reached.. even with a low SoC.
Also, during the charging session, the heat pump wasn't running at full bore like the first time I tried supercharging at low temperatures, which sounded like an outboard motor from inside the cabin. This time, the heat pump was barely audible, which again tells me that the battery temp was already satisfied for supercharging. This leads me to believe that the charging algorithm is dependent on outside air temp, not just battery temp, which is why 250kw was never reached.. even with a low SoC.
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Or maybe there is a bug that doesn't restart the preconditioning when you resume a navigation?
I don’t agree regarding the time it takes for the BMS to add/remove heat from the pack. It does so using conduction, which is a far more effective form of heat transfer when compared to convection (which is what you’re referring to when you say that cold outside air is cooling the battery). The heat generated from the motors is dumped into the hydronic loop that then passes through the battery. Eventually, the temp of this ‘loop’ will increase well past the 16-17C you mention... therefore heating the battery much more quickly than you’re suggesting.
Thanks to Bjorn Nyland on YouTube, I’m confident that the BMS can get the pack to whatever temp it feels is necessary, and in a relatively short amount of time when you consider the large thermal mass of the pack. If memory serves, the motors generate additional heat for this purpose whether or not the car is in motion.
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I just meant that the coolant only gets a handful of degrees higher than the battery. Yes it eventually gets hotter than 16-17 obviously. The heat exchanger in the motors might not be "great" , or a lot of heat is lost in the pipes before it gets to the battery. The battery temperature does not raise fast... All of what I'm saying comes from looking at scanmytesla in my car... Now, yes, the Y makes use of octovalve, on top of the front motor, i think.
Feel like sharing some screenshots, or even better, some videos? What you’re looking for should be obvious in the data.
When you navigate to the supercharger, the motors turn into ‘after burners’ (credit goes to Bjorn Nyland for this term), which generate a lot of heat, quickly. The loop temps at the ‘battery inlet’ quickly increase and the temps at the ‘battery outlet’ equalize with the battery inlet over a relatively short period of time. The examples I’ve seen are from Norway, which gets quite cold, on a M3 (I know, no heat pump).
If only I used Android, I would already be using one of those OBD Bluetooth dongles..
When you navigate to the supercharger, the motors turn into ‘after burners’ (credit goes to Bjorn Nyland for this term), which generate a lot of heat, quickly. The loop temps at the ‘battery inlet’ quickly increase and the temps at the ‘battery outlet’ equalize with the battery inlet over a relatively short period of time. The examples I’ve seen are from Norway, which gets quite cold, on a M3 (I know, no heat pump).
If only I used Android, I would already be using one of those OBD Bluetooth dongles..
TomServo
Active Member
He definitely knows his stuff when it comes to anything EV, especially Tesla.
My take away from that video is that it can take a full hour of preconditioning when outdoor air temps are between 20-30F in order to achieve a faster charging speed, but he doesn’t go as far as to say that you can achieve 250 kW in below freezing temps.
I also noted what he said regarding how the arrival SoC will affect preconditioning. If it estimates the SoC to be below 20% upon arrival, it will not precondition the battery. This definitely played a part during my test, but it did get maybe 25 min of preconditioning before it stopped.. So I’m hesitant to say that I could have made some adjustments during my test to achieve a faster charging speed. I’m starting to believe that the supercharging speed/algorithm is very much dependent on outdoor air temps, not just battery temps, and you should not expect to see 250 kW when outdoor air temps are cold enough, which could be between 40-50F if not higher, even though plenty of time was spent preconditioning.
My take away from that video is that it can take a full hour of preconditioning when outdoor air temps are between 20-30F in order to achieve a faster charging speed, but he doesn’t go as far as to say that you can achieve 250 kW in below freezing temps.
I also noted what he said regarding how the arrival SoC will affect preconditioning. If it estimates the SoC to be below 20% upon arrival, it will not precondition the battery. This definitely played a part during my test, but it did get maybe 25 min of preconditioning before it stopped.. So I’m hesitant to say that I could have made some adjustments during my test to achieve a faster charging speed. I’m starting to believe that the supercharging speed/algorithm is very much dependent on outdoor air temps, not just battery temps, and you should not expect to see 250 kW when outdoor air temps are cold enough, which could be between 40-50F if not higher, even though plenty of time was spent preconditioning.
In any case, 250kW is not available on a wide SoC range if you look at the charging profiles that people have posted on the internet (for model 3 LR). It might start tapering down as soon as 25%... I guess it might change with software updates but still, most people won't ever see 250kW if they arrive at 30-40% SoC. And Bjorn's video clearly shows that pre-heating the battery is essential for good speed and takes longer than we all expect.
This does give the impression that owning an EV is complicated... it's not, but you might not extract the maximum from it. It's like that for many things in life. Now, if Tesla would give a bit more info instead of hiding everything, it would help understand, learn, and adapt.
This does give the impression that owning an EV is complicated... it's not, but you might not extract the maximum from it. It's like that for many things in life. Now, if Tesla would give a bit more info instead of hiding everything, it would help understand, learn, and adapt.
How much time was the drive to the Supercharger?
Did you precondition prior to driving?
The battery pack is 1,000 lbs of mass. It takes a lot of energy (and time) to get it up to the temperature required for full speed charging (at least 35°C).
In my experience, just navigating to the Supercharger doesn’t condition for long enough to get it up to full speed. I can usually only get 200+ kW on my second charge of a trip after the battery is already good and warm.
So 83 kW at 31% at 47F doesn’t seem totally unreasonable to me, particularly if you only conditioned on the way there without prior driving or preconditioning.
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