2018 Tesla mode S 100D, Battery health percentage ?!

[Amr Wahbi]

My HV battery is still under warranty for unlimited kilometers till 2026
I'm worried about the battery's health, so I booked an appointment. The report came that the high voltage system has no issue, and the battery is 3.4% degraded above the average, they claimed the battery is in good health, and they will not replace it based on warranty but only based on failure!!!!!

Question: Is there a way to obtain the high voltage battery health percentage?


My Car : 2018 Model S HW3.0 MCU2.5 , SW version 2024.8.7 (upgraded Yesterday)

 

[ResHacker]

My HV battery is still under warranty for unlimited kilometers till 2026
I'm worried about the battery's health, so I booked an appointment. The report came that the high voltage system has no issue, and the battery is 3.4% degraded above the average, they claimed the battery is in good health, and they will not replace it based on warranty but only based on failure!!!!!

Question: Is there a way to obtain the high voltage battery health percentage?


My Car : 2018 Model S HW3.0 MCU2.5 , SW version 2024.8.7 (upgraded Yesterday)

Sure, check this. Your BTX6 100kWh battery was like 97kWh usable when new, so you can easily calculate it. Nevertheless, the most precise way is to fully charge it and then discharge to zero because the BMS numbers can be off the reality depending on the use of the car..

EDIT: And for your car there should also be a test procedure in service menu available for the degradation measurement.. It just takes a long time to go through obviously..

 

[Amr Wahbi]

Sure, check this. Your BTX6 100kWh battery was like 97kWh usable when new, so you can easily calculate it. Nevertheless, the most precise way is to fully charge it and then discharge to zero because the BMS numbers can be off the reality depending on the use of the car..

EDIT: And for your car there should also be a test procedure in service menu available for the degradation measurement.. It just takes a long time to go through obviously..

Thanks , very useful, question : How to discharge to zero ? there is no test procedure in the service menu

 

[ResHacker]

Thanks , very useful, question : How to discharge to zero ? there is no test procedure in the service menu

Ok, it probably depends on which SW version you are. And I thought it is a feature for MCU2 and newer versions, so maybe it's not the case. So then there's only one option - to drive slowly (around 90kph) till you're close to zero enough to be precise. You can watch Bjorn Nyland's videos on YT doing such tests, it's a plenty of fun

 

[Anth89]

Knowing the degradation won't help. On the Model S no acceptable level of degradation is defined in the warranty - only failures are considered.
Furthermore charging habits can have a huge influence on the capacity calculation made by the BMS.
Discharging to zero may not give you the full picture either, as there is an hidden buffer, and as the % indicator also considers temperature (ScanMyTesla shows it for example).

That being said degradation alone is never an issue on Model S. Battery changes are related to other failures and could not be predicted looking only at degradation.

 

[ucmndd]

they claimed the battery is in good health, and they will not replace it based on warranty but only based on failure!!!!!

And indeed they are correct. No degradation warranty on your Model S.

 

[oramos]

I have 2018 Model X in which the battery is performing very poorly. I had a dealer test it one year ago and it was at 80% or so versus the 70% required for replacement. Performance is much worse today than it was then.

I called Tesla and they said it was only 2% worse than las time but wouldn't give me any data..

I tried to do the test in the service menu but I dont have the option there and Telsa said that the feature had been removed. Is that true?

It is frustrating that there is no way to verify what Tesla is saying in terms of degradation. Is there any other way to verify?

 

[ucmndd]

I have 2018 Model X in which the battery is performing very poorly. I had a dealer test it one year ago and it was at 80% or so versus the 70% required for replacement.

A 2018 Model X has no degradation warranty at all. The 70% replacement threshold was introduced in 2020 along with the 150k mileage limit.

Your car has an 8 year unlimited mile battery warranty against failure, but NO warranty for degradation.

 

[oramos]

that isn't what dealer said but either way my question was about verification of what is really happening with battery

 

[ucmndd]

that isn't what dealer said

Then the “dealer” was wrong.

but either way my question was about verification of what is really happening with battery

You don’t have much choice but to deal directly with Tesla as they’re the ones providing the warranty. For your car it’s pretty simple:

Does the car show any alerts or error codes related to the battery? If yes, Tesla will evaluate them and determine if your battery is eligible for replacement under warranty. If no, you have no realistic warranty claim that will result in a battery replacement.

How are you determining the health of your battery is “much worse”? Note that failure to achieve rated range is not a valid measure of health.

What does your range display indicate when charged to 100%?

 

[Amr Wahbi]

Then the “dealer” was wrong.

You don’t have much choice but to deal directly with Tesla as they’re the ones providing the warranty. For your car it’s pretty simple:

Does the car show any alerts or error codes related to the battery? If yes, Tesla will evaluate them and determine if your battery is eligible for replacement under warranty. If no, you have no realistic warranty claim that will result in a battery replacement.

How are you determining the health of your battery is “much worse”? Note that failure to achieve rated range is not a valid measure of health.

What does your range display indicate when charged to 100%?

At 100% Charge, I'm getting a rated Range: of 554km and the Typical range:445km on Tesla screen), however the third part Tessie app gives me (real-world range of 352km & battery health of 87.4%)

what do you think?

 

[ucmndd]

At 100% Charge, I'm getting a rated Range: of 554km and the Typical range:445km on Tesla screen), however the third part Tessie app gives me (real-world range of 352km & battery health of 87.4%)

what do you think?

I think a new X100D was rated at 475km typical when new? If so that's ~7% degradation and perfectly normal.

Like I said... until your battery fails, there's no claim to be made. Just trying to be realistic about your expectations. Tesla is not going to replace your battery.