Battery kWh usable percentage - real evidence

[rush6410]

A question came up in another post about percentage of battery available for driving. There has been some debate that the 90kWh battery has less capacity for driving than the other battery offerings. I have seen many posts about perceived inadequacy specific to the 90kWh. There doesn't seem to be much evidence to support the claims. So, I decided to pull some data from the teslafi.com site.

The teslafi.com leader board captures the top 20 trips from all user data for each model and battery. The data works well for this purpose because it excludes vampire drain. The data only includes usage when the vehicle is not in "P" or driving. The site treats each leg of driving as a separate trip. All usage is consumed during the trip. The usage during the trip should be in theory very accurate if not exact. In order to be on the leader board you have to achieve the longest drive between stops. This allows for a single consumption period without interruption.

Assumption can be represented that each trip most likely started with a 100% charge. The battery percentage used should be 100% or very close to it. Again, no vampire drain. Usage is representative of all consumed kWhs for any reason; speed, road conditions, weather, a/c, fan, seat heaters.

Results for Model X (% of battery consumed / actual kWh consumed):

60kWh

• 76.79% of 60kWh battery usage / 46.07 kWh consumed

75kWh

• 75.15% of 75kWh battery / 56.36 kWh consumed

90kWh

• 79.89% of 90kWh battery / 71.9 kWh consumed

100kWh

• 76.23% of 100kWh battery / 76.23 kWh consumed

Conclusion - The 90kWh battery does not have a lower usage percentage available for driving. If anything, it shows it performs the best. You could argue that the 90kWh drivers outperformed other drivers. But, the volume of trips and data should even this out. Since the 100kWh models haven't been around very long, so you should see changes with that data.

See attached graphics for the details

 

[verygreen]

Your methodology is suspect.

When you look at the "leaderboard" and a huge percentage of it uses only does like 200 miles - that's just an indicator people using teslafi don't do long driving for whatever reason on 100kWh battery. I did ~200 mile trips on 80% charge myself.

Another hole is your assumption people charge to 100% - nope they most often dont for a variety reasons. E.g. because many believe it's bad for the battery, because charging to 100% on superchargers (what you use during long trips) is so long, and so on.


Here, run of the mill trip I did with a 90% charge or thereabout, would have occupied 4th spot in your table if I felt like giving away my personal driving data to third parties.

Also do note how many of the spots for 100D and 90D are occupied by the same username - further limiting your sample size and underscoring that many people don't do whatever these people do.

Edit: if you wanted to be representative, ask teslafi for a different leaderboard - the max kWh used in a single leg, with one entry per user, 20 entries max per model. - that'll tell you how many people don't charge to 100% I suspect

 

[rush6410]

When you look at the "leaderboard" and a huge percentage of it uses only does like 200 miles - that's just an indicator people using teslafi don't do long driving

With the number of drivers/users and trips per user you are looking at over 10,000 and only the top twenty are displayed. So with the lack complete user trip data and volume of trips. My assumption is at a minimum a very high probability.

Another hole is your assumption people charge to 100% - nope they most often dont for a variety reasons. E.g. because many believe it's bad for the battery, because charging to 100% on superchargers (what you use during long trips) is so long, and so on.

Only the top 20 are displayed. With the number of users and trips, it is a very high probability the longest drives were a result of a 100% charges.

Also do note how many of the spots for 100D and 90D are occupied by the same username - further limiting your sample size and underscoring that many people don't do whatever these people do.

I would say this proves my point that the users trying to make the top of the list is purposely doing so with 100% charges and a conscious effort to do so. So we are seeing the best of the best extended range drivers.

Edit: if you wanted to be representative, ask teslafi for a different leaderboard - the max kWh used in a single leg, with one entry per user, 20 entries max per model. - that'll tell you how many people don't charge to 100% I suspect

I would say enough of the users have charged to 100% with them being represented on the list. I agree that the 100kWh users data is suspect since it is from the smallest set of folks with the least amount of trips recorded. That is why we should see the 100kWh user data to change over time. The others have been around enough to get a good sampling.

I agree the data sets are less than ideal. But, unless you know of a better source with more user data, this is better than ambiguous complaints with no data points. I like your idea of asking teslafi to provide specific criteria of data to better show the results. I also need to add the model S to broaden the data. Bad idea to only include X. It just limits the samplings.

 

[gaswalla]

I wouldn't argue with verygreen... he's more than just an expert.

 

[rush6410]

No argument. Just looking at data.

 

[verygreen]

But, unless you know of a better source with more user data

The whole dataset of all Tesla cars has leaked, with precise BMS reporting of remaining battery capacity, yet you take a very small dataset and think it's better somehow?

The whole 100D chart is only 7 cars if we remove the repetitions. 90D chart is either 6 or 7 unique cars.

positions 4 and below on the 100D chart could be easily done on 90% charge (depending on conditions) and overall percentage of battery used is pretty low.

Sure it looks like about a couple of users on both were in a competition to top the chart and likely did some 100% charges and drove downhill heavily (achieving 103kWh on a 100D - not even theoretically possible unless you had some pretty extreme regen from some high place), but it does not really tell you much about what real 100% capacity is in what cars. (noticed how 90D results have 14 results with quite an elevation drop, and quite a few over a 1000ft? )

 

[rush6410]

The whole dataset of all Tesla cars has leaked, with precise BMS reporting of remaining battery capacity, yet you take a very small dataset and think it's better somehow?

I have seen and am not disputing that at all. I just thought it would be interesting to see user data with actual drives and where the numbers come out. The 103 is ridiculous.

 

[jaguar36]

This has no real meaning on usable battery capacity. You're comparing anecdotal evidence from a small subset of cars for which you don't have all the data (namely charge percentage) to data that is reported by the car itself.

That being said, it is interesting data to see.