Best way to charge to prevent battery degradation?

[AAKEE]

I usually charge in winter as soon as I get home as the battery is often warmer.. then it cools down at 60% or so.. I figured that's better than trying to charge at freezing ish temperatures

The regular theory is about like that….but:

The Tesla never charge the battery if it is freezing temps in the battery. In these cases it warms the battery first. No charging until the cell temp is well above freezing.

If you have a ”classic” Tesla (no heat pump) the charge at arrival could save a little energy, by charging when the battery anyway is warm thus reducing the need for battery heating.

If you have Tesla with heat pump, the leftover heat from a charging session (both battery heat and heat losses during the charging) can be used to heat the cabin.
In total the waist heat is not wasted, but used so in many cases this will be more efficient.

I always charge late, so I usually start the drives with a warm battery. Same road and same speed and same temperature, for example -20C, with warm battery it draws 185Wh/km but with cold battery 260Wh/km. (I have a post made here on TMC with data/pictures of this).

I would charge late anyway, to ”prove” the low SOC strategy but its the way to go with heat pump cars. Reduces degradation and at the same time, reduce consumption and increase the range.

 

[izzzyyd]

To put it in another way, 55% or lower will cut the degradation in half at least.

When you have 10% degradation, the low SOC-equivalent Tesla owner has 5%.

If you need to charge to 70-80-90% AND care about degradation, you can charge late. Minimizing the time above 55% works!

If you do not care at all, thats fine also. You battery most probably will stay alive to 8 years and above.

The thread however, is named

Best way to charge to prevent battery degradation?​

So, if you do not care its not a thread for you.

I will never curse anyone that do not care, or like to charge to 90% every day to get maximum power of a performance car.
Thats fine, or even a good thing.

I will try to kill the myths, so any statement science knows is wrong, I will try to kill

Reading “I have now understood, but I will continue to charge to 90% to have maximum power every day, and I know it will not be the lowest degradation but its worth it” warms my heart.

Any other reason, and even ”Because I don’t care” is OK.

”I charge to 90% as Tesla say I should and I know this will minimize degradation as Tesla say charge to 90% and dont go below 20%”
This guy will loose capacity because he was caught by the myths. Said.

I mean what is the timing aspect of charging to 80%? When I charge to 80% the longest it’s at that charge is 12 hours if I do it at night. So it’s not like it’s spending 99% of its life at 80%.

I mean I can try 55% but **** that’s almost daily charging I have the base model 3

 

[AAKEE]

I mean what is the timing aspect of charging to 80%? When I charge to 80% the longest it’s at that charge is 12 hours if I do it at night. So it’s not like it’s spending 99% of its life at 80%.

I mean I can try 55% but **** that’s almost daily charging I have the base model 3

Do you have the RWD model? which year was it built? You might have a LFP battery, then slightly different values apply.

For example, the timing aspect: Did a full charge the other noght. My car was sitting with 30% during the evening and night from the day before.
The plan was to start the drive at 10.00 AM, and with 11kW 70% ( = 55kWh) was ~five hours calculated by mental arithmetic. so the charging was set to commence at 05.00AM.
The time at over 55% SOC was from about 07:00AM to 12:00AM, so five hours in total, from charging to driving down below.

 

[izzzyyd]

Do you have the RWD model? which year was it built? You might have a LFP battery, then slightly different values apply.

For example, the timing aspect: Did a full charge the other noght. My car was sitting with 30% during the evening and night from the day before.
The plan was to start the drive at 10.00 AM, and with 11kW 70% ( = 55kWh) was ~five hours calculated by mental arithmetic. so the charging was set to commence at 05.00AM.
The time at over 55% SOC was from about 07:00AM to 12:00AM, so five hours in total, from charging to driving down below.

I don’t think it’s LPF gross weight is off and shows daily trip on charging screen.

RWD standard plus 2021

 

[izzzyyd]

Kinda concerned its 12K miles and already 5% degradation I know it’s supposed to taper off and stay there basically but still.

 

[izzzyyd]

Currently waiting for the model 2 performance pick that thing up and resell this or give it to my mom.

With the newer batteries it doesn’t even matter you’ll probably be dead before the battery dies if the new supposed 6000 cycle is correct. That’s a 1M - 2M mile car.

Even 3000 cycles would be pretty insane

 

[AAKEE]

Kinda concerned its 12K miles and already 5% degradation I know it’s supposed to taper off and stay there basically but still.

From the daily/trip screen we can know its Panasonic NCA.

The degradation in relation to miles ”isn’t”.

Most of the degradation the first five eight years comes from calendar aging.
If you charge to 70-90% you probably will have around 4-6% calendar aging the first year
The higher value or more in a warm climate and the lower in a cold.
After 1 year 5%
After 2 years 7%
After 3 years 8.7%
After 4 years 10%

The standard range/base model usually is used with larger cycles (as the battery is smaller). This increases the cyclic wear, but its still much less than 1% each year.

Your cars 12K miles implies its not driven that much so. Your car is roughly two years?
I would guess you actually have about 7-8% degradation from the calendar aging.
Driving little will put a EV below the average degradation line, as these use miles/km on the X-axis. But if we disregard the miles and look at the time, it will be very close to the average line.

I did create a calculation program for degradation. If you give some data, I can calculate the approximate expected degradation. With this we can compare the expexted degradation with your cars.
Its probably spot on, but…

-Location/average temp: NY ? (12C/53F?)
-Manufacturing month or purchase month
-Do you have a garage or is it parked outside?
-Charging level
-What SOC (charging level) do you have after a normal day
-When do you charge? Daily (?), at what time does it start
-Odo reading (12K miles?)
-lifetime average consumption

 

[AAKEE]

Currently waiting for the model 2 performance pick that thing up and resell this or give it to my mom.

Model 3 Performance I guess?

If you get a new M3P in US, you get a battery with the same battery cells as your 21 standard range (+) has. It do not have the LFP battery. (LFP would be too heavy and would be too large for a Long Range/Performance car).

Using high SOC like 70-90% will “cost” about 5% the first year, and 10% after four years.
This is Teslaloggers data on M3P 2021, use the same battery since.
Original range is 507km(315 miles). The average line depends on the average ODO/miles/km so driving less would out us below.
We should expext the same as usual degradation with this car.

With the newer batteries it doesn’t even matter you’ll probably be dead before the battery dies if the new supposed 6000 cycle is correct. That’s a 1M - 2M mile car.
Even 3000 cycles would be pretty insane

The LFP’s withstand many cycles, and is not sensitive to large cycles. But the calendar aging still works about as before, so we will se about the same defradation curve - remember that for the first years calendar aging is the dominating factor.

This is the SR+ LFP data:
The curve looks about the same as calendar aging still does its thing.
It will flatten in the same way as the other cars.

 

[izzzyyd]

From the daily/trip screen we can know its Panasonic NCA.

The degradation in relation to miles ”isn’t”.

Most of the degradation the first five eight years comes from calendar aging.
If you charge to 70-90% you probably will have around 4-6% calendar aging the first year
The higher value or more in a warm climate and the lower in a cold.
After 1 year 5%
After 2 years 7%
After 3 years 8.7%
After 4 years 10%

The standard range/base model usually is used with larger cycles (as the battery is smaller). This increases the cyclic wear, but its still much less than 1% each year.

Your cars 12K miles implies its not driven that much so. Your car is roughly two years?
I would guess you actually have about 7-8% degradation from the calendar aging.
Driving little will put a EV below the average degradation line, as these use miles/km on the X-axis. But if we disregard the miles and look at the time, it will be very close to the average line.

I did create a calculation program for degradation. If you give some data, I can calculate the approximate expected degradation. With this we can compare the expexted degradation with your cars.
Its probably spot on, but…

-Location/average temp: NY ? (12C/53F?)
-Manufacturing month or purchase month
-Do you have a garage or is it parked outside?
-Charging level
-What SOC (charging level) do you have after a normal day
-When do you charge? Daily (?), at what time does it start
-Odo reading (12K miles?)
-lifetime average consumption

 

[izzzyyd]

I read NMC also shows daily trip? I have standard RWD 21 model 3 it’s still NCA?

 

[izzzyyd]

Also charging above 55% what is most detrimental just charging or the amount spent at that state?

As sometimes I charge to 80% drive right away and end the day near 55%

 

[AAKEE]

I read NMC also shows daily trip? I have standard RWD 21 model 3 it’s still NCA?

Yes, NCA.

In US all Teslas was NCA in the beginning.
(NCA was superrior in energy density)
SR went LFP 2021 circa.
The new 4680 in Model Y RWD seem to be NMC.

Also charging above 55% what is most detrimental just charging or the amount spent at that state?

As sometimes I charge to 80% drive right away and end the day near 55%

We need to think that the degradation is split in two parts.
What part is calendar aging and what part is cyclic aging.

For the calendar aging we only should think [time x temp x SOC]. Reducing time at high SOC is good, specially high SOC at high tempersture.

If you charge to any value from 55% or below and drive asap to 55% or below directly you will only have ”increased” calendar aging during the time from the charge passes 55% om the way up until the SOC drains below 55%.

Cyclic wear is higher from larger cycles, but the cyclic wear is anyway smaller than the calendar aging for most of us.
So, the increased part of cyclic aging is mot large and itbis not time dependent.

 

[izzzyyd]

Gotcha yeah going to start playing around with charge to 55 when I reach my destination.

My only concern is either the time remaining at super chargers is wrong or it always defaults to 25 minutes no matter what

If I could go to a super charger and charge up to 55% within 5-10 minutes that would be ok.

Another hassle is trying to go off peak hours

 

[gad1976]

I’m a higher mileage driver (average 3,000 per month). Picking up a new MYLR in a few weeks (June). My schedule changes daily. At random I need to travel 200-600 miles in a day. The other days are 0-100 miles.

Trying to apply the info from this thread it seems I should charge to 55 when I return home and then set the car to charge a second time to a higher rate over night on the days I know I’ve got a longer trip.

Because of the nature of my job I need about 150 miles of range at any given time.

With this method, about 15 days a month I will return home and charge up to 55% and the car would sit for 24-36 hours in this state. The rest of the month I would need it too be at 80-100% by morning so I could leave with a “full tank” for the road trip.

Under the circumstances does this seem like a good plan to preserve the longevity of the battery?

In almost every case I’ll be getting home with less than 20% charge.

In some cases I would charge up to 55% when I get home and the battery is still warm, then would charge again over night to reach the 80-100% levels needed for the long trip.

I’d like to baby the battery. I usually drive my ice cars to between 300,000-400,000 miles. Almost exclusively highway driving. I’m taking a gamble with switching to electric because it’s new tech for me. I’d love to get 300,000+ out of this model y. (Historically I drive a car 10+ years)

Thanks in advance for your thoughts.

P.S. I live in Wisconsin so have cold winters. I have read a lot about cold weather range loss and have made peace with that. The super charges are well spaced for my needs. I’ll be using them on average 10 times per month.

 

[jcanoe]

I’m a higher mileage driver (average 3,000 per month). Picking up a new MYLR in a few weeks (June). My schedule changes daily. At random I need to travel 200-600 miles in a day. The other days are 0-100 miles.

Trying to apply the info from this thread it seems I should charge to 55 when I return home and then set the car to charge a second time to a higher rate over night on the days I know I’ve got a longer trip.

Because of the nature of my job I need about 150 miles of range at any given time.

With this method, about 15 days a month I will return home and charge up to 55% and the car would sit for 24-36 hours in this state. The rest of the month I would need it too be at 80-100% by morning so I could leave with a “full tank” for the road trip.

Under the circumstances does this seem like a good plan to preserve the longevity of the battery?

In almost every case I’ll be getting home with less than 20% charge.

In some cases I would charge up to 55% when I get home and the battery is still warm, then would charge again over night to reach the 80-100% levels needed for the long trip.

I’d like to baby the battery. I usually drive my ice cars to between 300,000-400,000 miles. Almost exclusively highway driving. I’m taking a gamble with switching to electric because it’s new tech for me. I’d love to get 300,000+ out of this model y. (Historically I drive a car 10+ years)

Thanks in advance for your thoughts.

P.S. I live in Wisconsin so have cold winters. I have read a lot about cold weather range loss and have made peace with that. The super charges are well spaced for my needs. I’ll be using them on average 10 times per month.

When you will be charging your Model Y at home what will be your charging setup and charging rate? Do you plan to charge using the Tesla Wall Connector at 48 amps or charge at something less than 48 amps?

 

[gad1976]

When you will be charging your Model Y at home what will be your charging setup and charging rate? Do you plan to charge using the Tesla Wall Connector at 48 amps or charge at something less than 48 amps?

Yes, I am planning to install and charge using the Tesla Wall charger at 48 amps.

 

[jcanoe]

Yes, I am planning to install and charge using the Tesla Wall charger at 48 amps.

Assuming you would want to leave for a road trip with 90% state of charge (there is no need to charge to 100% when you can use the Supercharger network.) Plan for X hours of charging at 48 amps, i.e. from 50% to 90% and see if you are comfortable with waiting 3 plus hours before leaving. I would set the daily charging level so you are comfortable with the time needed to top up to 90% before departing. Your time is valuable, you should not have to be inconvenienced by having to wait for charging to bring the battery to an acceptable level before starting a trip. Assume charging at 48 amps can add ~42 miles of range per hour while charging (maybe use 40 miles per hour when charging as a conservative estimate).

 

[Art84]

Yeah.. don't babysit the battery. Charge to 80% daily and it will give you 150 miles of guaranteed range any given time (except maybe cold winter).
Recommendation to keep battery about 50-60% related more to the storage of the battery... when you don't drive, or drive occasionally, better to keep lower SOC. But it's not your case.. since you drive a lot, your battery will naturally spend more time in lower levels of SOC, because you often will be somewhere in the roadtrip.

 

[D.E.]

We need to begin with the 0% definition.
It is not completely empty. This is the first, important thing. People interpret 0% as zero, completely dead. Well, it’s not.

0% is the energy level (voltage on each cell) where we should stop discharging.

No, you don’t get to redefine zero to something else, then expound the something else as if it was truly zero, I don’t care how many posts you’ve made.

You can say that Tesla will display zero when there’s 4.5% energy capacity left. That is just Tesla’s display of a level of their minimum level of acceptable discharge and where they draw their arbitrary line to prevent further discharge and battery damage. It does not give a new definition of zero.

So your arguments are simply that if the battery is discharged to a level of 4.5-5% remaining, it will last longer. OK. That’s fine. But the battery is not run down to zero voltage.

So we don’t need to “begin with the 0% definition”. Zero is and will always remain zero, zilch, squat, none, nil, nothing left. And that, my friend, is bad for batteries.

Words have meanings. And those meanings should not be clouded by every Tom, Dick, and Harry, who thinks it’s handy to substitute their own meaning for the original definition. If one wants to describe something in new terms, use a new word, or signify that it’s a qualified meaning, such as “Tesla displayed 0” for example.

I think it’s great that Tesla stops the discharge before one can harm the battery. I’d expect nothing less.

And thanks for all the data about battery life cycles when used down to “Tesla displayed 0” with a true 4.5-5% remaining.

 

[AAKEE]

So we don’t need to “begin with the 0% definition”. Zero is and will always remain zero, zilch, squat, none, nil, nothing left. And that, my friend, is bad for batteries.

In this case, you’re wrong.
You can have your own opinion but 0% SOC is not completely Dead empty.
I am not talking opinions but technical terms, as they are used and defined by the manufacturers.

If 0% was completely dead empty, how could you then overdischarge a battery?

Words have meanings.

Yes, they have!

In the world of batteries, the 0% SOC is defined as the stop discharge (cut off) voltage, 2.5V in many cases for lithium ion like Tesla NCA.
Its not my opinion, it is the wide spread definition by manufacturers of the batteries.

This is the specification of the ncr18650, you can look at the cut off voltage (2.5V):
https://www.omnitron.cz/_dokumenty/792019122953866/ncr-18650.pdf

Here is one example from Samsung SDI, lithium battery manufacturer. See SOC 0% vs OCV, open circuit voltage:

https://embdev.net/attachment/491363/SDI94Ah.pdf

And thanks for all the data about battery life cycles when used down to “Tesla displayed 0” with a true 4.5-5% remaining.

You can say that Tesla will display zero when there’s 4.5% energy capacity left. That is just Tesla’s display of a level of their minimum level of acceptable discharge and where they draw their arbitrary line to prevent further discharge and battery damage. It does not give a new definition of zero.

The 0% displayed on a Tesla does’nt mean we can not drive beyond that. We can, and the minimum allowed pack voltage is 240V, thats 240/96 cells, 2.5V/ cell just as Panasonic set the 2.5V /cell as the minimum.
From SMT reading the BMS in my car:

Tesla allow us to drive down to 0% SOC, 2.5V/cell. There is even som other SOC numbers in the BMS, of which one shows the true SOC which ends up with 0% at the 240V minimum level.

If you take a Tesla cell and charge it to 100%(4.2V) and then discharge it to 2.5V, you get a 100% Depth of Discharge (DoD).

Then the degradation will be like this:
All these was dishcarged to 0% / 2.5V.
4.2V = 100%
4.1V = 90%
4.0V = 80%

If you look at the 4.2V/100% it could stand about 650 cycles. Thats 650 x 400km, so 260K km or 160K miles.
(the grey lines is most representative for driving a Tesla or charging it).
If you look at the 4.0V /80% it could stand 1000 Full equivalent cycles, thats 400K km or 250K miles.

Every one of these cycles was down to 0% SOC.
0% SOC doesnt brake the batteries, but stopping at 3.0V or so would reduce the degradation, if 400.000km isnt good enough.