Model Y: Daily Use changed from 90% to 80% in last week or so...

[epmadsen]

Hi - so I noticed a couple of other threads where this is being discussed. But today I dropped into 2 different Tesla service centers and didn't quite get a definitive answer.

I took delivery of my Model Y in March of this year. Tomorrow I'll have over 11K miles. Up until about a week ago, the Daily Use bracket went from 50%-90%, and now it dropped to 80%. I stopped at a 72kWh charger a week ago, and it temporarily bumped back to 90%.

The reason I was dropping a new thread is that one of the Tesla service guys and I jumped into a loaner Model S (not sure of the year) w/ almost 60k miles and it showed daily use from 50%-90%. It was on the current firmware.

Then we got into one of the Model Ys and that also was current firmware, but showed the daily use from 50%-90%.

I started wondering if I was experiencing some kind of battery degradation (I have heard charging at Superchargers all the time can be bad? Others say no - but my condo has no charging units in the garage yet).

And since there are numerous folks speculating that this is the latest firmware that made this change, then wouldn't we see this across all MYs and/or other Teslas?

The MY we stepped into this afternoon - maybe it had the newer battery? I'm told those are ok to charge to 100%. I don't believe mine has that from March.

 

[jcanoe]

New Model Y vehicles will have the factory build firmware. The firmware won't be updated for several weeks (at least) after delivery to the customer.
In my 2020 LRMY the 80% recommended for daily charging message appeared once I installed version 2023.26.7 and now on 26.8 the 80% recommended for daily charging message continues to be displayed on the charging screen and in the Tesla app whenever I set the charge limit higher than 80%.

During lockdown times I got in the habit of charging to between 80% and 85% every other day. 3 years on I see no reason to change. I estimate that after 38 months and almost 16k miles my Model Y has lost 10% of the original 74kWh useable capacity. (My 2020 LRMY was delivered with a one page Tesla printout stating that the battery capacity (when new) of my 2020 LRMY was 74kWh. This document was provided by Tesla for a State of Maryland EV rebate program that was in effect the time I took delivery.) Most of the charging has been Level 2 (~200V and 30 amps) at public L2 charging stations. I have charged my Model Y using a Supercharger a total of about a dozen times.

 

[rubenarakelyan]

I wondered about this as well since the app and car always advised 90% charging for daily use, then it suddenly changed to 80% after an upgrade. I was wondering if this is a change across-the-board or maybe it's tied to the age of the car, charging patterns or something else? I rarely use a Supercharger and mainly charge overnight at home.

Mine's a 2022 Model Y.

 

[tga]

I wondered about this as well since the app and car always advised 90% charging for daily use, then it suddenly changed to 80% after an upgrade. I was wondering if this is a change across-the-board or maybe it's tied to the age of the car, charging patterns or something else? I rarely use a Supercharger and mainly charge overnight at home.

Mine's a 2022 Model Y.

My 23 MYLR showed 50%-80% for daily use when I picked it up w/ 6 miles. Firmware 2023.26.100.

 

[jcanoe]

I wondered about this as well since the app and car always advised 90% charging for daily use, then it suddenly changed to 80% after an upgrade. I was wondering if this is a change across-the-board or maybe it's tied to the age of the car, charging patterns or something else? I rarely use a Supercharger and mainly charge overnight at home.

Mine's a 2022 Model Y.

From the Tesla software version 2023.32.x Release Notes

The recommended daily charge level has been updated for some vehicles. Depending on your vehicle, the types of batteries it uses and where it was manufactured, Tesla may have lowered the recommended daily charge limit.

Tesla Software Updates & Release Notes - Latest Tesla Updates

 

[EV_Dad]

From the Tesla software version 2023.32.x Release Notes

The recommended daily charge level has been updated for some vehicles. Depending on your vehicle, the types of batteries it uses and where it was manufactured, Tesla may have lowered the recommended daily charge limit.

Tesla Software Updates & Release Notes - Latest Tesla Updates

Thanks. With your help I also found it in the 2023.26 release notes: 2023.26 Official Tesla Release Notes - Software Updates (Search for "Daily Charge" Limit.)

My Model Y started recommending 80% after the 2023.26 update, but my Model X does not recommend any specific charge ceiling.

 

[rubenarakelyan]

Thanks both for your insights, I obviously missed the memo with the release notes! I wonder if it'll make a difference if I continue to charge to 90% for daily driving. 80% seems a little low for some of our journeys...

 

[Noflash]

Thanks both for your insights, I obviously missed the memo with the release notes! I wonder if it'll make a difference if I continue to charge to 90% for daily driving. 80% seems a little low for some of our journeys...

Fwiw, I'm charging to 85%. 80% was keeping me under 200 miles for too long for my comfort.

 

[Mulkogi]

Nah 90% all the way

 

[Mateo83]

I speculate it is damage control. Batteries are seeing worse degradation than Tesla anticipated.

 

[Rocky_H]

80% seems a little low for some of our journeys...

If it's a journey (trip), then you use the trip setting, which is that higher area from 80% to 100% for more range as needed. Use it.

 

[Darmie]

AAKEE has shared new chart data that shows how higher SOC affects calendar aging. Notice even charging up to 80% for daily still affects degradation. 55pct or lower has the lowest calendar aging degradation. That's true percentages, not what's reported by car. There is usually 4 to 5 % buffer in what's reported.

Some new data from research on Tesla model 3 cells

There has recently been released a series of new research reports containing tests on Tesla Model 3 Cells (Panasonic 2170 NCA). This is the calendar aging test from one of them (25C, 15, 50 and 85% SOC. Checkup once a month): Using the datapoints from these and putting them in the old charts I...

teslamotorsclub.com

I share this as food for thought. One must charge to the level that you need for daily use. What I understand though is, if you are leaving your SOC higher than 55% for any length of time, calendar aging will affect degradation. Probably more so than cycling aging.

 

[flixden]

AAKEE has shared new chart data that shows how higher SOC affects calendar aging. Notice even charging up to 80% for daily still affects degradation. 55pct or lower has the lowest calendar aging degradation. That's true percentages, not what's reported by car. There is usually 4 to 5 % buffer in what's reported.

Some new data from research on Tesla model 3 cells

There has recently been released a series of new research reports containing tests on Tesla Model 3 Cells (Panasonic 2170 NCA). This is the calendar aging test from one of them (25C, 15, 50 and 85% SOC. Checkup once a month): Using the datapoints from these and putting them in the old charts I...

teslamotorsclub.com

I share this as food for thought. One must charge to the level that you need for daily use. What I understand though is, if you are leaving your SOC higher than 55% for any length of time, calendar aging will affect degradation. Probably more so than cycling aging.

So when I set the car to 55%, what would that translate to in terms of real charge? 60%, and I'd be clearly over the 55% target? Or 50%, and there would be a healthy margin?
Maybe @AAKEE will chime in ...

 

[AAKEE]

So when I set the car to 55%, what would that translate to in terms of real charge? 60%, and I'd be clearly over the 55% target? Or 50%, and there would be a healthy margin?
Maybe @AAKEE will chime in ...

The buffer is 4.5% below 0% displayed.
At 55% displayed you have 55 + (100-55 x 0.045) = 57%. This is on the safe side!

The central graphite peak is at 57-58% when the battery is new. Staying at or below is safe.

This means that 55% is the highest ”safe” number on a new NCA pack.
Of course the 55% ”advice” was already set with regard to the true SOC.

The central graphite peak moves up (higher SOC) from regular calendar aging and cycling, so it is safe long term at 55%.

The central graphite peak moves down from lithium plating, so supercharging will probably move it down slightly.

In the end, for normal use, the central graphite peak most probably moves up as we do not supercharge all the time, so 55% should be safe long term.

The new data in the link from my post do not really show anything new regarding to calendar aging. The new data covers small cycles at different SOCs (and the research test used higher currents for charging/discharging than we have using our cars, so it might be a bit off from real EV use.)

 

[rubenarakelyan]

If it's a journey (trip), then you use the trip setting, which is that higher area from 80% to 100% for more range as needed. Use it.

Yes appreciate the difference and I do charge to 100% sometimes when I have a long trip coming up. Daily use was 90% until it suddenly started advising 80%. What is not very clear is how much extra ageing happens by regularly charging to 90% instead of 80%. So I can't work out if the extra ageing is worth the slightly higher inconvenience of nearly always having 20% of the battery capacity essentially out-of-bounds. I only supercharge on trips, the vast majority of charging is at home.

 

[brainhouston]

What is not very clear is how much extra ageing happens by regularly charging to 90% instead of 80%.

Most likely negligible...
80% limit update came out just recently but same cell chemistry been used since 2012...
Many Model S/X drivers see no significant deviation from average no matter what settings or chargers they use.
Most significant aging component seem to be - (you'd never guess haha)... age

Side note, it matters more how long car sits at higher SOC, just like 100% recommendation, drive as soon as its charged.
So if u charge to 90% n drive every day you'll probably be better off than a car sitting at 80% n barely driven...

 

[AAKEE]

Yes appreciate the difference and I do charge to 100% sometimes when I have a long trip coming up. Daily use was 90% until it suddenly started advising 80%. What is not very clear is how much extra ageing happens by regularly charging to 90% instead of 80%. So I can't work out if the extra ageing is worth the slightly higher inconvenience of nearly always having 20% of the battery capacity essentially out-of-bounds. I only supercharge on trips, the vast majority of charging is at home.

Well, it is nothing new with the batteries.
It is not any new finding about degradation.
Neither 80% or 90% is even close to the values of the lowest degradation.

It is either a damage control to reduce degradation slightly in very hot environments, or just a adjustment of the number as more or less no one needs more than 80% for daily driving.
The ones needing > 80% daily is actually doing [trips] and can use the full 100% when needed.

If 80% covers what you need to the mext charge, its fine. If not, increase the level ss needed.
BTW, low SOC is not bad so you can use what you need with the discression of your range anxiety.

 

[AAKEE]

Most likely negligible...
80% limit update came out just recently but same cell chemistry been used since 2012...
Many Model S/X drivers see no significant deviation from average no matter what settings or chargers they use.
Most significant aging component seem to be - (you'd never guess haha)... age

Initially they had only two choises of charging level.
I do not remember the year but this is the update info:

BTW, note that they told to nit charge more than needed for battery life.

Side note, it matters more how long car sits at higher SOC, just like 100% recommendation, drive as soon as its charged.

Tesla has not issued a recommendation to drive asap after a charge, that is forum myths.
In general, SOC above 60% cause about the same degradation unless it is very hot where the high SOC wear slightly more.

So if u charge to 90% n drive every day you'll probably be better off than a car sitting at 80% n barely driven...

Thats right!

 

[Vicj]

I don't think the new 80% suggestion had anything to do with battery chemistry, battery life, degradation, or anything at all to do with extending the life of your car. I believe it's much simpler than that. It's about more revenue. Tesla is about to roll out a surcharge for supercharging beyond 80%. They are going to charge a higher rate if you go beyond that at a Supercharger, so they are now "suggesting" 80% to get people used to that figure. It's pretty simple.

 

[epmadsen]

They are going to charge a higher rate if you go beyond that at a Supercharger, so they are now "suggesting" 80% to get people used to that figure. It's pretty simple.

Speaking of which, I've been stunned by how much prices have been going up, at least in LA. As of last week I saw .71/kWh at several places. I figured this would happen but not at this pace.