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Very high charging rate

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Drove from Long Island to Rochester, NY yesterday. Stopped an Tannersville, PA supercharger on the way and continued up to Rochester. When we reached Victor, NY (just outside Rochester) the car was down to 30 miles, so we did a "pit stop" When I plugged into the charger, it quickly jumped up to 476 miles per hour. We walked into the local mall, used the facillities and walked back to the car. The A/C system was screaming. Heat was pouring out of the front of the car. I assume that this was the A/C trying to cool the battery because of the high rate of charge.
My question is--- Is this rate of charge safe for the health of the battery? I've seen rates of 350 MPH, but never 476.
 
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What was the reported rate in KW?
I had a supercharging session a few weeks ago that reported the full 120kW up to about 50% soc. For that portion is was reporting 498 miles/hr.
Of course it dropped off significantly as the charge rate tapered to 90% soc.
I’m assuming it was fine. I actually wonder if it will be able to go higher with the next gen supercharger
 
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Drove from Long Island to Rochester, NY yesterday. Stopped an Tannersville, PA supercharger on the way and continued up to Rochester. When we reached Victor, NY (just outside Rochester) the car was down to 30 miles, so we did a "pit stop" When I plugged into the charger, it quickly jumped up to 476 miles per hour. We walked into the local mall, used the facillities and walked back to the car. The A/C system was screaming. Heat was pouring out of the front of the car. I assume that this was the A/C trying to cool the battery because of the high rate of charge.
My question is--- Is this rate of charge safe for the health of the battery? I've seen rates of 350 MPH, but never 476.

As others have said, what you experienced is totally normal and awesome! That is your car working as intended. It is amazing how fast it can charge when at a low state of charge and on a unconstrained supercharger!

Tesla seems to know what they are doing with batteries. So while not fantastic for the battery, you don’t really get to change anything when supercharging speed wise, so that is just what you get. I would not worry about it!
 
It's fine, the Model 3 can handle it at a low SOC. It won't stay that high forever. As the battery SOC increases, the rate will decrease.

Does it damage the batteries, no. Can hard driving followed by hard charging, repeated many times degrade your batter life? Yes, and you'll see a pop-up after a few Supercharging sessions in a row. But even some of the high use vehicles are suggesting that it may only barely degrade the batteries.
 
C238DE5B-71FE-4BF8-81FF-3EA84F14BB51.jpeg
I got up to 493 mph when charging last night.
I was at 119/120 kW for a while but it started to drop a bit at around 45% soc.
Got a photo this time right after taper started.
This was at Burlington NJ. (Same location I saw 498 mph earlier)
Charged from about 20% to 88% in 38 minutes.
 
My question is--- Is this rate of charge safe for the health of the battery? I've seen rates of 350 MPH, but never 476.

The battery can take quite some high temperatures. Using the CAN bus I check the battery temperature on my Model S all the time. When driving my battery is generally at around 40 C (105 F). When driving fast or supercharging it sometimes gets up to 55 C (130 F). That's about when the car starts to reduce the charge power a little bit. While this is rather hot, it's not a condition the battery is in for a long time. It's perfectly fine and nothing to worry about. Tesla is really good about keeping the battery temperature within a reasonable range.
 
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Why would you want to?
I'm sure there are owners who are used to reducing their charging rate to match the time they plan to be away from the car, and expect to apply the same logic to superchargers. But as has been said, the whole point of supercharging is to be done as fast as possible, for two reasons: 1) so you can resume your journey without delay, and 2) so the stall is freed up quickly for another person to use.
 
Why would you want to?

If you want to reduce your rate, you'd find another stall with a guy charging next to it. Sucks to be the other guy though. There are small hard to measure benefits of reduced power charging and drawbacks (waste of your time and others). Your best bet is to find the 72 KW urban chargers.

Supercharging will not "damage" your battery (lithium plating), but it may cause accelerated degradation compared to L2 charging. How much is not well measured by the public although Tesla probably knows. I don't imagine it to be a large difference like ZOMG my battery died early, but rather a small difference.

The key point is that the battery is pushed up to higher temperatures during a supercharge than otherwise. I believe the same thing happens in ludicrous setting in the Model S (internal resistance decreases with increased temperature providing more power but accelerating battery wear).

Here's a nice document demonstrating accelerated battery aging at various SOCs. Tesla uses a propriety mix of NCA/NMC chemistry. Top charts show capacity fade, bottom charts show power fade. Their exact test procedure may be questionable though, but its a useful data point for academics.

F2.large.jpg


Calendar Aging of Lithium-Ion Batteries

KEY POINT
The Tesla charts I've seen for capacity fade look extremely promising (supercharging or not), but I really don't know how they're able to maintain such low capacity fade relative to other manufacturers (low cycle life? better temp management? enhanced calendar life?). That's assuming the data reported by users is accurate of course.

If I was to venture a guess and assuming the charts above are correct, I'd assume something like 1-2% difference in capacity fade with supercharging vs. without. Well worth it for the time you save. The outliers are probably poorly maintained batteries (high temperatures, low mileage with no balancing, defective modules, etc.)

Another data point to consider is that my 2014 Chevrolet Spark EV (LFP chemistry) was built in 09/2013, and by the time I sold it 5 years later (08/2018), it was at about 81% of original capacity.

Tesla must've nailed the calendar life chemistry component with the Model S early on.
 
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So how is power distributed amount a set of stalls. Are they paired? Are they all running off some common super AC/DC converter?
I don't think I'd want to put my car through what the OP saw. I'd be happy with 400 mph.
 
So how is power distributed amount a set of stalls. Are they paired? Are they all running off some common super AC/DC converter?
I don't think I'd want to put my car through what the OP saw. I'd be happy with 400 mph.

So the charging speed is controlled by temperature in the battery I am sure (perhaps with other metrics too like cell voltage). He was probably seeing huge rates since the battery was not too hot yet at that point.

Tesla does not want you to block the supercharger stalls for long so I highly doubt they will create an option to slow down the chargers.

To answer your question: When talking about a non-urban supercharger, there are typically two stalls paired with a single cabinet full of 12 charger modules. It has something like 146 kW (someone else may have the precise amount) of capacity. These are shared between two cars when two cars are charging.

I really would not worry about this too much. From the data we have, superchargers don’t seem to really have a horrible impact on the batteries. Optimally I would avoid always using superchargers, but I have zero issues using them any time I need to (which for me is nearly never).