Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[AlanSubie4Life]

Then why don't they have 82 kWh like the other Panasonic NCA packs? That's the question. Particularly with the less efficient Y they would want to have a higher energy if they could.

We have no SMT reads from these packs though, do we?

All I know for sure is it is not uncommon for Model Y LR 2024 to have at least 79.5kWh which is very comparable to prior years. (Around 80kWh was common.)

The weird thing is the EPA result being 79kWh rather than 81kWh-82kWh. (These >81kWh levels could be seen in vehicles with SMT when brand new, but it was pretty unusual I think - 80.5kWh-81kWh was more common, briefly.)

So is there an actual difference? Seems to me most likely no, but SMT data would be good to get (at least get the full pack when new hard-coded value)…

 

[Geir]

Picture below is from cycle tests of real model 3 cells.
5-15% might look ”worse” but to begin with, as Tesla has a 4.5% buffer below zero on the display the 5-15% here is virtually like doing 0-10% on a tesla display.

The battery lost ~ 17.5% for 3000FCE (thats actually 30.000 such cycles 10-0%.

3000FCE is about 3000 x 400 km, so 1.200.000 km.
This is about 0.3% degradation per 20K km which might be a normal annual driving distance.
So if 0.3% is deemed ”worse” for one year we meed to compare it to ~ 5% calendar aging for the most common ”charge to 80% daily” for the first year, and ~ 10% calendar aging after 4 years.
View attachment 1023019

No, low SOC is not bad. We need to understand that cyclic aging means choosing between very very low cyclic degradation and very very very low cyclic degradation and if we hunt for this we probably will shoot ourself in the foot.

The sweet spot might be like i mostly use my car, between 55 to 30-35% but still, the calendar aging is so much higher the first five years if you try to avoid low SOC and end up at staying above 55% for a considerable part of the time.

First: Thanks for your efforts to guide us in charging-habbits, AAKEE!

My M3RWD LR 2019 say that I have 71 kW in the battery today after 76 000 km and close to 5 year. Calculation done like this: 192 x 296/80 = 71kWh > (77,8-71)/77,8 = 8,7% degradation. Is this normal?

The first 3 years I normally charged to 70%, and the 2 last year to 50%. (And also SC 9% of total charging, without precndition)

 

[AAKEE]

First: Thanks for your efforts to guide us in charging-habbits, AAKEE!

My M3RWD LR 2019 say that I have 71 kW in the battery today after 76 000 km and close to 5 year. Calculation done like this: 192 x 296/80 = 71kWh > (77,8-71)/77,8 = 8,7% degradation. Is this normal?

The first 3 years I normally charged to 70%, and the 2 last year to 50%. (And also SC 9% of total charging, without precndition)

Its lower than average degradation, but about as expected counting your lower SOC after three years and the climate.

The average cell temp is setting the degradation pace in the same way as SOC does. (But it is often not so easy to decide the ambient temp).

I would guess - southern Norway would have a rather low annual average temp.

I would guess the first three years would have degraded the battery about 7.7%, and the last two about 1%.

 

[Geir]

Ok.
I think the temperature is about + 5 degree median, from -15 to + 25.
I got from 70 to 50% charging too late.

Then if I follow the 50-55% rule forward, when will i need to change the battery? I would like to keep the car as long as possible. (I know that this is a difficult question…..)

 

[AAKEE]

Ok.
I think the temperature is about + 5 degree median, from -15 to + 25.
I got from 70 to 50% charging too late.

Then if I follow the 50-55% rule forward, when will i need to change the battery? I would like to keep the car as long as possible. (I know that this is a difficult question…..)

With 55% or less you can be sure that you will not wear out the battery. Most probably not with normal charging habits either.
The batteri can develope other issues from the electronic parts etc, but i guess ypu will not wear it out.

Melsomvik seems to have aroubd 9C average annual temperature. I used that as the base, so ~14-15C cell temp in average or so. (Cells heat from both driving and charging).

I have anly a annual temp a few degrees above freezing and had 13.5C average temp on my M3P. (Normally Parked in a garage with around 10C during the cold part of the year.)