10% battery equals 6 kWh??? Model X 75D

10% battery equals 6 kWh??? Model X 75D

I’ve tested this numerous times. Here’s the latest

Charged car to 90% at a supercharger and immediately started driving. No AC and no Radio, lights off (daytime)

Drove 29 miles using 9.2 kWh (317 Wh/M) and my batter dropped 15% during this non stop driving.

Continued driving to the 63 mile mark using 20 kWh and my meter is at 57%

If you divide kWh by the percentage drop I get .6 kWh per 1% of battery or a total of 60 kWh measured in my battery.

Minus the 10% top and bottom buffers, I only have 48 kWh usable battery which equals about 150 mile range.

What the Heck?

Bighorn | 2 januari 2020

I think I see the problem. You thought 75 kWhs were available for locomotion. Study your history. The 2012 Model 85s provided 73 kWh. Every iteration is different, but there’s your likely explanation. They space superchargers so that the least capable vehicles can take advantage of the network—that would be yours, I think. | 2 januari 2020

@Joespinney - There are so many variables you didn't talk about. The range is reduced by:

- Headwinds
- Rain
- High speed (EPA is 65 mph)
- HVAC (cabin cooling and heating)
- Cold, requires heating the battery
- Larger than 18" tires
- Going up hills

Range and EPA numbers are based on 65 mph, 70F, flat terrain.

Joespinney | 2 januari 2020

All those things affect range, true. But when those variables impact the Wh/m reflects. But I am not talking about range. I’m talking about actual useable battery size. How is tall 30 kWh equal 50% of my battery. Regardless of variable impacting the Wh/m. My car was recording the actual rated 317 Wh/m during this run.

If my car actual has a useable battery size of 60 kWh, then they should sell it as a 60 not a 75

And if that is the case, then the 236 mile range (75/0.317= 236) is impossible even under the best conditions. The real range should 60 kWh divided by the 0.317 rating or 189 miles.

Bighorn | 2 januari 2020

Gosh, this was all fleshed out about 5 years ago, but you glossed right over the answer that addressed your misapprehensions. Why you think your individual result of 317 Wh/m has anything to do with EPA results is also vexing.

Bighorn | 2 januari 2020

Pertinent facts worth sharing would be the build date and mileage along with the rated range at 100%SOC. Longer drives (uninterrupted) give more precise data. | 3 januari 2020

@Joespinney - Confusions like yours is why Tesla has dropped specifying the battery size on new cars. The watts/mi is the number that matters and if you drive in a way that uses more power than the EPA gets, then your range will be less. Conversely, if you drive with lower W/mi values than EPA, you'll get a longer range than the EPA states. | 3 januari 2020

Perhaps another way to think of it - it doesn't matter if you have a 50 kW or a 200 kW battery if the EPA range for both is some number, say 300 miles. What that means is the 50 kW system is incredibly efficient, while the 200 kW system is truely awful efficiency. You're paying for range, not battery size, although bigger batteries do cost more. Some cars like the new Taycan has very poor efficiency. Model 3 is one of the best today. The X is better than the Taycan but not as good as the 3.

Bighorn | 3 januari 2020

He seems mad that he's not getting "what he paid for." False advertising in his mind over the fact that anyone who had done their due diligence would have easily discovered, that 75D doesn't mean that the full 75 kWh of the battery is devoted to locomotion. Lay media suggests 72.5 kWh were originally available for 238 rated miles or 304 Wh/m to achieve the rated range. I'm not aware of any 75D owners who were as diligent as we were about determining battery capacities on the original S85s, so I go with the google answer. His experiment does suggest capacity in the low 60s which may be poor methodology or degradation, but it's hard to judge not knowing the age or mileage of the vehicle. My 85 kWh battery only provides around 63 kWh at this point.

Joespinney | 4 januari 2020

My lifetime Wh/m average is 351

Car 16 months old with 16000 miles.
When I bought the car the mileage at 100% SOC was 236 but now it’s only 220.

FISHEV | 4 januari 2020

"When I bought the car the mileage at 100% SOC was 236 but now it’s only 220."

7% degradation. I've got 3% after 15,000 miles. Your's sounds high though Tesla will say 10% 1st year and 15% cumulative by 2nd year is "Within Normal Limits".

Get StatsApp for Tesla which has a nice battery health graphic to see what the car thinks is the battery degradation. There's also a companion app Battery Health which shows your car's battery degradation vs. other Model 3 owners.

Bighorn | 4 januari 2020

Tesla has no statement about degradation for the Models X or S. FISHEV, the resident troll from the Model 3 forum, is comparing battery statements about the Model 3 along with his "degradation" figures from a different vehicle with a totally different battery architecture.

Back to the point--with 220 rated miles, if the the 72.5 kWh original figure is accurate, you should be able to recognize almost 67 kWh of energy on an uninterrupted trip. When you only test for 29 miles for instance, the accuracy of your estimate is broad because 15% represents 14.5% to 15.5%. This would extrapolate to a range from 187 to 200 miles or nearly a 7% spread, which coincidentally is your purported "degradation." Of note, varying rated range figures are multifactorial and cannot be assumed to be pure or absolute degradation.

Your lifetime average (35Wh/m) is pretty unremarkable as few people seem to match the EPA figures. Not sure exactly what you meant about the unusable 10% buffers on either end. There's no issue with using the full range of the battery when necessary, which is typically on road trips and increasingly unnecessary with the proliferation of supercharging stations.

Coldfire73 | 16 januari 2020

The high 10% buffer is the "you really shouldn't normally charge over 90%", and the lower 10% buffer is the "Yikes.. I only have < 20miles left to get to a charger!" (Which, at least for me, is a concern based on the lack of chargers, Super or otherwise, in my part of the UK right now)