Excessive degradation?

[EYSA]

Is my 2021 MYP having more than normal degradation? When performing full charge it gets to 99% and showing 263 miles. I believe the car when new was at 303 miles at 100%. The car has 34k miles and always charged to 80%. I may be calculating it wrong but dividing 263/303 = .8679 so 14% loss? am I doing anything wrong?

 

[ucmndd]

The only “excessive” degradation threshold that matters is 30% as that’s when the warranty kicks in. Anything else is “normal.”

You say you always charge to 80%, but can you talk a bit more about your charging habits? Do you charge every day? Big discharges or do you keep the state of charge in a narrow band? Have you ever let the car charge to 100% to get a better sense of true capacity?

 

[Eric33432]

For daily driving it is best to charge every day to what you need, not blindly charge to 80%.

For example, if you use less than 30% of the battery for daily driving, only charge to 50%. If you are going to be driving more, then charge higher the night before, just for such days.

And some people wait until the battery is down really low and then charge up to 80%. Better to charge every day...for example, if you charge to 50% and drive it down to 40%, go ahead and charge it. Of course, this only works if you have charging at home or work, would be very inconvenient it you are using the Super Charger to charge.

 

[AlanSubie4Life]

Is my 2021 MYP having more than normal degradation? When performing full charge it gets to 99% and showing 263 miles. I believe the car when new was at 303 miles at 100%. The car has 34k miles and always charged to 80%. I may be calculating it wrong but dividing 263/303 = .8679 so 14% loss? am I doing anything wrong?

Normal.

If you read around @AAKEE has some fairly well researched recommendations on what to do to reduce loss going forward. Though benefit is probably minimal at this point, it might help with battery aging a bit. You won’t be recovering significant capacity or anything like that of course (basically impossible though there is some evidence of slight recovery with lower SOC, it is not clear what the reality is - and is likely not significant even if it does happen).

Short answer is always be charging, and keep charge limit below 55% (or no higher than you need). Lower charge limits are better (50%). Delay charging but always be charging to minimize cycle depth.

And just don’t worry about it too much.

He can fit your car to a formula if you want.

13%-14% is perfectly normal for your described charge level and your location. Your calculation is correct.

On your next EV you can try a different strategy so you have more capacity for when you need it, and to improve resale value.

Or if you want your power just always charge to 90% - it is fine. You just get maybe 70-90% more degradation than at 50%. Not a huge deal unless you are in it for the very long term. (Might impact likelihood of battery failure but very unclear.)

 

[howardnj]

I charge to 90% daily and plug in as soon as I'm home for the day.
If it turns out there is a problem with that, it will be the next owners problem as I will no longer own it after the warranty runs out.

 

[Prodock]

Sounds about normal. I had a 2022 MYP, drove 100 miles a day and using the same calculation as you I dropped to about 265 miles of range in the first 8-10k miles. It stayed right there for the next 40k miles though. My estimated range was 263-265 when I traded it in for a MX a month ago.

 

[foxwiz5262]

My 2023 Model Y has a 264 mile range at 80%. Purchased the car in August 2023. I have 7600 miles on it and now when I charge back to 80%, it shows a range of 255 (usually from 50% or greater). Not sure why this is. I did some research and others say to wait until the mileage goes down to about 50 or 60 miles, then charge it back to 80%. I did that twice and did get the 264 mile range. Why is this happening?

 

[AlanSubie4Life]

My 2023 Model Y has a 264 mile range at 80%. Purchased the car in August 2023. I have 7600 miles on it and now when I charge back to 80%, it shows a range of 255 (usually from 50% or greater). Not sure why this is. I did some research and others say to wait until the mileage goes down to about 50 or 60 miles, then charge it back to 80%. I did that twice and did get the 264 mile range. Why is this happening?

You're claiming the BMS claimed a 318-mile range and then it popped back to 330-mile.

This could happen, but it is a fairly large swing. Anyway long term you're going to see the 80% number go down.

It's a direct measure of your battery capacity, but it is an estimate by the BMS, so there can be error. So the number can go up and down, even though in reality the trend of actual energy in the pack is only down.

Expect the number to be about 6-10% lower than where it started in about 2 years. The rate of capacity loss will drop off after that. It's a square root (roughly) relationship with time. If you charge to less than about 55%, you'll see a lower rate of loss.