Battery charging dilemma - wrong kWh

[axalam]

Hey everyone, I have a question about battery percentage. So I have a 90D. I recently charged my car at a supercharging station.

When I came in to the supercharger my car was at 6% and I charged it all the way to 80%. So that’s an addition of 74%. Based on the fact that the car is a 90D, an addition of 74% means an addition of +68.4kWh (based on 1% = 0.9kWh). But instead of showing that my car added 68.4kWh during the charging session, my car only shows +46kWh.

I am very confused. Am I reading something wrong or are my calculations incorrect? Has anyone else experienced this? I feel like my battery is depleted or malfunctioning somehow.

 

[ucmndd]

The 90kwh battery was never actually 90kwh to begin with, it’s about 85kwh. Then there is a buffer of about 4kwh that you can’t use. So really your battery when brand new only had about 81 kWh for propulsion. And of course it’s degraded in the 5 years since then.

Your battery is fine.

 

[axalam]

If I calculate correctly, 46kWh/74% = 62kWh. So out of the “90kWh”, my car only has a usable charge of 62kWh. The battery warranty states that the battery should have Atleast a capacity of 70% and this goes below 70%.

Any chance Tesla will look into this and replace the battery under warranty?

 

[ucmndd]

If I calculate correctly, 46kWh/74% = 62kWh. So out of the “90kWh”, my car only has a usable charge of 62kWh. The battery warranty states that the battery should have Atleast a capacity of 70% and this goes below 70%.

Any chance Tesla will look into this and replace the battery under warranty?

Your car actually pre-dates any capacity guarantee. You have an 8 year unlimited mile warranty against failure, but NO warranty for degradation.

Tesla will tell you your battery is 100% fine. This method you’re using to calculate capacity is rife with flaws and unlikely to yield you any satisfying outcome.

 

[P85D-low-range]

Your car actually pre-dates any capacity guarantee. You have an 8 year unlimited mile warranty against failure, but NO warranty for degradation.

Tesla will tell you your battery is 100% fine. This method you’re using to calculate capacity is rife with flaws and unlikely to yield you any satisfying outcome.

Can you please tell me more about this? my 2015 model S p85d has been getting low range for years. Is there any way I can get it replaced under warranty? Tesla has been telling me for 3-4 years that it's normal and battery is fine. But it's clearly not.

 

[ucmndd]

Can you please tell me more about this? my 2015 model S p85d has been getting low range for years. Is there any way I can get it replaced under warranty? Tesla has been telling me for 3-4 years that it's normal and battery is fine. But it's clearly not.

No, Tesla will do nothing for you. The original Model S/X had an 8 year, unlimited mile warranty for the high voltage battery and drive units. Failure only - no warranty for capacity or degradation.

After the Model 3 was introduced, Tesla moved to 8 year mileage bound warranties. Sometime in 2019 I believe the S/X moved over to this 8 year / 150,000 mile warranty that guaranteed at least 70% of the original battery capacity during that period.

But again, pre-2019 cars have NO warranty for battery capacity / degradation.

 

[P85D-low-range]

So if it fails suddenly, will I get a new replacement or an old new stock 85 kWh battery? And what will the range likely be?

How does one get it to meet the conditions of failing (since degradation isn't enough)?

 

[ucmndd]

So if it fails suddenly, will I get a new replacement or an old new stock 85 kWh battery? And what will the range likely be?

Completely up to Tesla based on what they have on hand. Very likely refurbished. The warranty says they owe you a replacement battery with at least as much range as the one they replaced before it failed.

How does one get it to meet the conditions of failing (since degradation isn't enough)?

You could try by charging constantly to 100%, supercharging a lot, etc etc. But until the car throws an error, you just wait.

 

[BrownOuttaSpec]

FYI, here are the battery stats for my MS90D with about 69,000 miles on it:

If you get something like Scan My Tesla and required hardware (scan my tesla) then you can see all the real battery stats and not have to rely on doing weird math.