P90D Supercharging Data

[liuping]

A couple things:

1. I assume the data point at 23 % was a typo since that = 150 kW. We've never seen rates above 120 kW.

2. You're 90 kWh seems to have followed the less aggressive taper that was observed by Pete90. I'll need to take a closer look for sure, but just eyeballing it, your data indicate slower charge rates for a given percentage compared to my 85 kWh.

Yes, you're correct 23% should be 303 Amps, not 403. I've updated the csv. Thanks for catching that.

The taper could be effected by the outside temp, it was nice an cool last night.

 

[apacheguy]

Maybe but doubtful. I've SpC in everything from 50 -> 90+ and not noticed much difference. Generally the cooler the better as long as the pack isn't cold soaked. I think there is something different about the cells that prevents them from being charged as quickly.

On critical point that I always look at is the 90 kW cross over. On B+ 85 packs this occurs 40-45%. Your data indicate that the mark was crossed at 33%, a whole 7-12% lower than the same taper point on an 85 kWh.

If you are interested in an example of this for comparison see:

Supercharge Pack Rev E - 120kW supercharger - No Audio - YouTube

 

[ArtInCT]

liuping:

I massaged your SuperCharger data, rounding UP in all cases and made this handy chart which perhaps many P90, P90D and P90DL owners may find informative when planning their SuperCharger Stops. Oops the lower image is in error... But I cannot get rid of it. :cursing:

 

[liuping]

View attachment 101650

I massaged your SuperCharger data, rounding UP in all cases and made this handy chart which perhaps many P90, P90D and P90DL owners may find informative when planning their

Thanks. That is a very handy chart.

(To delete the incorrect image, edit the post in advanced mode, and click on the "manage attachments" button further down the page)

 

[apacheguy]

For further comparison, an 85 kWh takes 52 minutes to go from 16-90% (from the above referenced video). The 90 kWh, while having more capacity and thus expected to take a bit longer, in reality takes 12 additional minutes. This points to a steeper taper curve.

 

[liuping]

For further comparison, an 85 kWh takes 52 minutes to go from 16-90% (from the above referenced video). The 90 kWh, while having more capacity and thus expected to take a bit longer, in reality takes 12 additional minutes. This points to a steeper taper curve.

90% on an 85kWh pack is about 85% on a 90kWh pack, which took about 56 minutes in my test.

At least that is small enough, that other factors will likely make a bigger difference in the total time stopped at the SuperChargers.

 

[sorka]

I ran the test last night. I arrived with 16% and charged until 90%. It took 1 hour and 4 minutes. Outside temp was 61 degrees. There was on one other car at any given time at the sight (and they were not using my paired charger)

Visual Tesla did indeed do the sampling inconsistently. It did most about 4 minutes apart, then some just one second apart. However, I also manually logged the Time, Volts and Amps each time the % went up by one, so I think I have all the data we need.

I'm not sure the best way to add it to the existing data, since I have sample data at each % increase, and the graph data is per minute. Should I have excel plot a graphic and then resample the curve at the existing time stamps used in the google doc?

I can try to do that tonight (I'm not great at Excel, but me wife is an expert), or if anyone wants to give it a try, I put the CSV data here: https://www.dropbox.com/s/a2c3a4rmbwzkabi/supercharge.csv?dl=0

Another data point for a P85D. We drove from Merced, CA to Tejon Ranch just before the start of the grapevine. Arrived with 19% and charged to 96% in 60 minutes. I had only planned to charge to 90% in order to skip several super chargers so I could make it all the way to Indian Wells, CA where the hotel had an HPWC. Normally I'd charge just enough to make it to the next supercharger and leave as soon as possible, but we didn't want to rush and spent an hour at dinner across the street at this fabulous Mexican restaurant called Maricios.

Anyway, I forgot to set the charge setpoint to 90% and by the time we finished dinner and walked out, it had been exactly an hour since we plugged in and it the car was at 96%.

 

[apacheguy]

Yeah, Mauricio's is great to hang out at while you're juicing up.

 

[apacheguy]

90% on an 85kWh pack is about 85% on a 90kWh pack, which took about 56 minutes in my test.

Was just revisiting this thread when a thought popped in my head. The 85 kWh charges faster than the 60 kWh despite having increased capacity. The 90 kWh should by extension be faster as well, but in reality it is slower. Go figure.

See Bjorns video Supercharging Tesla Model S 60 kWh vs 85 kWh - YouTube

 

[Pruitt]

Was just revisiting this thread when a thought popped in my head. The 85 kWh charges faster than the 60 kWh despite having increased capacity. The 90 kWh should by extension be faster as well, but in reality it is slower. Go figure.

As I understand it, the 90 battery has a slightly different chemistry than the 70 or 85. That probably accounts for the somewhat slower charging rate of the 90.

 

[llavalle]

As I understand it, the 90 battery has a slightly different chemistry than the 70 or 85. That probably accounts for the somewhat slower charging rate of the 90.

The reason why there is such a difference between the 60/70 and the 85/90 is because the voltage of the pack is not the same. Most electrical components have a limit in Volts but more importantly, a limit in current (amps). Since the superchargers are limited to around 330amp (according to the graphs in the post) there's only so much power that can get to the pack. Power, in Watts, is voltage (volts) * current (amps).

Since the 90kWh battery has the same voltage as the 85kWh but needs more energy to be filled up, I expect it take more time to charge...especially since the fast part of supercharging (the first 5% of SOC) are probably current limited.

In theory, at equal voltage and same charging spec (C rating), a bigger cell will be able to get more current. Just google "battery C rating" and you'll get more info but basically, a battery cell is rated at a C rating for charging and a C rating for discharging. This is a ratio of the capacity...

ex : a 3200mAh battery with a charge rating of "0.5C" can be charged up to 0.5*3200mA = 1600mA max. That is called the "CC" phase, or "Constant current" phase. At one point, you hit max battery voltage and cannot put more voltage on the charger to get more amps flowing, you're now in the "CV" or Constant Voltage phase. In the case of most Lithium batteries, this voltage is 4.2V. That means that the charger will provide 4.2V to the battery cell and it stops when it see less than a specified amount of amps flowing towards the battery.

That being said, supercharging is not CC/CV, it's a super weird curve!

 

[apacheguy]

As I understand it, the 90 battery has a slightly different chemistry than the 70 or 85. That probably accounts for the somewhat slower charging rate of the 90.

Oh, undoubtedly it's due to the different chemistry. Just confused why Tesla went in the opposite direction of progress in this instance.

In theory, at equal voltage and same charging spec (C rating), a bigger cell will be able to get more current. Just google "battery C rating" and you'll get more info but basically, a battery cell is rated at a C rating for charging and a C rating for discharging. This is a ratio of the capacity...

Good points, but not sure I follow here. At equal voltage, the 90 kWh pack draws less current than the 85 kWh.

Since the superchargers are limited to around 330amp (according to the graphs in the post) there's only so much power that can get to the pack.

Also, note that a 70 kWh exceeds 330 amp draw on the low end.

 

[supratachophobia]

I wish I had known this before getting the battery upgrade. This is one of those pieces of info that Tesla could have disclosed so that customers could make a more informed decision. An extra 12min at a supercharger is huge.

 

[AWDtsla]

I wish I had known this before getting the battery upgrade. This is one of those pieces of info that Tesla could have disclosed so that customers could make a more informed decision. An extra 12min at a supercharger is huge.

Known what exactly? I don't see why everybody is comparing battery percentage and ignoring that the 90 has 6.4% more usable kWh than the 85 which is also 6.4% more range per percent. Need to remove 6.4% time the 90 times, or better yet, compare range added.

 

[apacheguy]

Known what exactly? I don't see why everybody is comparing battery percentage and ignoring that the 90 has 6.4% more usable kWh than the 85 which is also 6.4% more range per percent. Need to remove 6.4% time the 90 times, or better yet, compare range added.

Sure, I'll take you up on that. In the above referenced video, an 85 went from 16->90% and added 193 miles in 52 minutes. Can you top that?

 

[Cottonwood]

Sure, I'll take you up on that. In the above referenced video, an 85 went from 16->90% and added 193 miles in 52 minutes. Can you top that?

Having done a lot of runs with Superchargers spaced at every 100-130 miles, the comparison that makes the most sense to me is how long does it take to charge from 25 to 200 rated miles, giving 175 rated miles to make it to the next Supercharger. Make the metric how long it takes to add a fixed number of rated miles, rather than percentage or absolute energy; rated miles are the closest metric that we have that relates to actual range. Also, I like to plan on a low number of rated miles on arrival at a Supercharger, but 25 rated miles is as low as I want to normally arrive.

 

[supratachophobia]

Known what exactly? I don't see why everybody is comparing battery percentage and ignoring that the 90 has 6.4% more usable kWh than the 85 which is also 6.4% more range per percent. Need to remove 6.4% time the 90 times, or better yet, compare range added.

Known that it appears, according to the charging percentage rates, as though the s90 teachers longer to put the same amount of miles into the car. So while it goes 6.4% farther, it takes longer to charge.

 

[AWDtsla]

Known that it appears, according to the charging percentage rates, as though the s90 teachers longer to put the same amount of miles into the car. So while it goes 6.4% farther, it takes longer to charge.

Your statement is contradictory. If it takes the same amount of time to charge the same amount of range, then it is not slower. Percentage be damned. To me it looks like it takes less time, and I don't see anything directly contradictory above. Waiting for someone to point out this data.

 

[supratachophobia]

Your statement is contradictory. If it takes the same amount of time to charge the same amount of range, then it is not slower. Percentage be damned. To me it looks like it takes less time, and I don't see anything directly contradictory above. Waiting for someone to point out this data.

Twelve extra minutes for one of the most popular charge ranges.....

16-90% 52 min compared to 64 min. That's more than 6%longer.

 

[ohmman]

So while it goes 6.4% farther, it takes longer to charge.

16-90% 52 min compared to 64 min. That's more than 6%longer.

So it takes 6% longer to get about 6.4% more range.. or am I missing your point?