My almost 4 year old model 3 has battery degradation of 14.3% according to the Tessie app. in the little graph they show it shows me well below the fleet average. Is this somewhat normal for people or is my battery way worse than most?
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Battery Degradation question
- Thread starter robl45
- Start date
GreenCoffee
Member
I did experience similar degradation, LR RWD 2018, max range shows 281 at 100% and is a bit below fleet average, I routinely charged to 90% and accidentally left battery at 100% overnight on a few occasions while traveling on road trips and after returning from them while leaving max charge set to 100% so while I cannot say I abused the battery I have not been cautious with it either.
RayK
Active Member
Data point from another 2018 LR RWD @ 26.6K miles: My estimated 100% charge range is just below 300 miles. I charged yesterday up to 90% (my usual limit) and estimated range was 269 miles. That puts my degradation at about 6%, assuming the EPA rated range of 315 miles. Note that for the last 3.5 years I've been DC charging mainly at a CHAdeMO station so the power transfer is less than 50kW; typically it's more like 40kW and below since I tend to charge when the battery is about 50-55%. I've also used a Urban Supercharger but only when it's more convenient (shopping at a local hardware store) as the cost is double what the ChargePoint CHAdeMO stations offers.
edit: My lifetime Wh/mi is 236:
edit: My lifetime Wh/mi is 236:
Last edited:
RayK
Active Member
What's your efficiency and charging habits? I see you're in Florida so it's not like you're driving in the freezing cold.So basically mine is really bad
Charge on the wall charger most of the time to 90%. I think I run around 313 or so with avg around 277 maybe.
What model do you have? Long range?
What number do you see in blue text on the meter in Tessie, and what number does the "usable capacity" say?
I also think there should be a full range number in miles, what does is say?
Do you know the range shown at the battery symbol at 100% charge?
Asking because, as it seems the Tessie numbers are not always correct.
But we can sort it out by betting some info from you.
AlanSubie4Life
Efficiency Obsessed Member
236rmi @90% implies 262rmi @100%
“Nearly 4 years old” suggests it could be a 2020 Performance purchased in late 2019.
We would need to know if it is a 2020 model to provide you a capacity loss estimate. Your join date also suggests it could be a 2020. (I didn’t bother to look at detailed post history. Edit: I looked…looks like bought used… July 2019 build…so should be 2019…)
2019: 262rmi*245Wh/rmi=64.2kWh
They both started at 77.8kWh.
So either 17.5% (a bit high)
64.4 is quite low. The ramge numbers support that as well.
Original battery capacity was 77.8 kWh(Full pack when new).
Displayed Range started dropping below 76kWh for 2019 at least.
So thats about 18% if uding the full pack when new value.
15% from the 76 kWh.
It might be possible that the BMS is off downwards, underestimating the capacity…
Where do you live?
Have you had it since new?
How has your charging hanit been, what SOC do you regularly charge to and do you charge when arriving st home?
Car outside or in garage?
AlanSubie4Life
Efficiency Obsessed Member
In short, the battery is melting.
However, it is possible you could benefit from discharging to a much lower SOC (say 10%), let the car sleep for a couple hours, then charge it up again.
Usually this doesn’t help much but it also doesn’t hurt at all. And sometimes it actually does work. Only likely to help if this is something you don’t already do routinely.
In general use a lower SOC. But if you want the performance or need the range just leave as is. The damage is mostly done now anyway.
I must almost have your twin. 2019 Performance, 64.4 usable, 90% is 236mi.. exact numbers as yours.
Purchased new Sept 2019. My 100% would still range between 300-310 miles up until i got FSDb back around Nov last year 2022.
Ever since then range been dropping like a rock. I had around 60k miles before FSDb and now im at 70k miles. All that loss in a matter 10kmiles. Driving/charging habits remains the same.
The initial capacity is not always correct, most often below the normal initial capacity, like showing 75 kWh or do on the 77.8 kWh old model 3 pack for example.
Also, the name the equivalent to nominal full pack usable capacity. Most people read bothe these as usable (without buffer).
As a result people go around believing they have for example 2.9% degradation but a check of values might point to 6 to 10%.
In this thread the OP do see 75.2 kWh as the original capacity, and the degradation is showing 14.3% which is lower than it is.
(From 77.8 to 64.4 = 17.2% or from the degradation threshold 76 to 64.4 = 15.3%)
Initially it was hard to know if the programmers behind did mean that the values was excluding the buffer, as many think (in that case either reconing with a too low buffer or too high capacity).
So we did get the answer from the vendor that the tessie numbers include the buffer in both values.
If you degrade i to >30% you only will get a new pack that is guaranteed of holding up to max 30% degradation the day the car is 8 years.
How much energy do you use an average day? ( so it is at about 31K miles today?)
My car is 2 years and 3 months, and at 37K miles. I charge to 55% daily, and only charge higher when I need the range. From this, I have about 2-4% degradation so far, depends from what vaule we calculate degradation from. Your 17.2% is my 4%, your 15.3 is my 2%.
As you most probably wont get a new battery* and any harm you do to it from today will stay with you as long as you have the car it could be a good idea to try reducing the degradation.
*) Most probably you will not reach the 70% capacity limit, and if you do they will get you a referbed battery that keep you on the right side until 8 years old.
Calendar aging, which has been the thing that took almost every degradation for you, will reduce the rate with the time. In you're case the formula says square root( 8years/4 years) * 17% = 24% when the car is eight years old. It is probable that it will even be sightly less becuase the really long term calendar aging is redicing more than *square root of time*.
I live in a much cooler climate wich is favorable but the SOC level is as important. In your case, you can not do much about the ambient temp (except maybe store in a cool garage) but you can use a SOC level that is better for the battery (this means staying at or below 55% as muych as possible).
If more than 55% is needed, charging as late as possible so the charging is done shortly before the drive.
This alone would cut the degradation from today and in the future with half.
The big reduction at 55% and below is seen here.
Calendar aging is [Time x Temperature x SOC]
We can not affect the time, and hardly the temperature but we can affect the average SOC.
zoomer0056
Active Member
zoomer0056
Active Member
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