What Percent is Your Tesla Charged to While at Home?

[melvladimir]

2023.20.9

This is an older one. I had 90% too. Wait for 2023.26.1. Or maybe they will revert to "90%" (very low probability)

 

[AAKEE]

But they had the same batteries, as I know, due to the same dual motor (and acceleration boost option). I can't quickly find what I watched, but I focused on EU LR versions 2021-2022 (and had doubts regarding 2022 due to Rizen, which has 5% more consumption than Atom), and had been choosing between US/CN and CN won.

No, its not the same batteries.
What I wrote is real facts about LG and panasonic.

The ryzen do not have 5% more consumption, it has a battery witj lower capacity.

For the M3P with the 82.1kWh battery at WLTP 567km, it then was reduced to 547km when the battery was changed to the LG.

82100/567 = 144.8Wh/km

144.8 x 547= 79200Wh, thats more or less the LG capacity.

I had a m3P with the 82 kWh battery.
When using sentry mode (intel atom awake) it did draw 220W.

The Ryzen in my new car draws 290W in nu total with the sentry mode.
If you drive 5-6 hours before depleting the battery would use 70Wh more each hour.
Thats 350-420Wh difference during this time, so a 2-3km difference.

I don't know. I saw "551 km" maximum on a photo, when I got it, there were 95% and 521 km and that estimation was real. After that, I didn't charge till 100%. I'll pick a suitable time and try 5%->100%, but it's also good to have some OBD app.

Did you see 551km on screen at the battery symbol?

Each km is worth 137Wh at 100%.
551 km = 75.6kWh capacity.
Looks like the 78.8kWh battery after a slight degradation.

You can do the energy graph calculation, it is as exakt as the nominal full pack with scan my tesla.

 

[flixden]

@AAKEE (and everybody else): here is a follow up question:
Assuming I charge to 50% at home, and for a period of time, only consume ~5% SOC during my daily commute (short drives).
Which of the two below would be better for the battery?

(1) recharge daily (go down to 45%, then recharge to 50% the same day, then repeat)
(2) don't charge daily, and let the SOC go down to 20% (5% per day), and then on day 6, charge from 20% ---> 50%. Then repeat.

I am sure #2 would be better, but it would not follow the "charge often" advice. But: it would result in a lower average SOC over time, which is good.
What do you guys think?

 

[E90alex]

Recharge daily

 

[flixden]

Recharge daily

Alex, would you mind explaining what led you to your conclusion? I would have thought the other way.
Thanks for the response, btw!

 

[E90alex]

Alex, would you mind explaining what led you to your conclusion? I would have thought the other way.
Thanks for the response, btw!

Smaller depth of discharge is better than running it low first then charging.

 

[flixden]

Smaller depth of discharge is better than running it low first then charging.

Ok. It's better that way also in case an unexpected trip comes up, as the SOC is held at 50%. I thought the other way only because the average SOC over time would be lower, like 35% vs close to 50% or so.

 

[johnny_cakes]

Ok. It's better that way also in case an unexpected trip comes up, as the SOC is held at 50%. I thought the other way only because the average SOC over time would be lower, like 35% vs close to 50% or so.

Not sure which model/battery you have, but the difference between 35% and 50% average SoC for calendar aging is minimal and you probably won't notice it:

For cyclic degradation, smaller depth of discharge is better as @E90alex said, but again, the difference is marginal. I would choose what's most convenient for you. I'd charge daily to 50%.

 

[AAKEE]

@AAKEE (and everybody else): here is a follow up question:
Assuming I charge to 50% at home, and for a period of time, only consume ~5% SOC during my daily commute (short drives).
Which of the two below would be better for the battery?

(1) recharge daily (go down to 45%, then recharge to 50% the same day, then repeat)
(2) don't charge daily, and let the SOC go down to 20% (5% per day), and then on day 6, charge from 20% ---> 50%. Then repeat.

The calendar aging tests with high resolution shows that calendar aging is virtually the same between about 30-55%.
This means that there is no big difference in calendar aging if the battery is at 30-35 to 55%*

For cyclic aging which actually is very small for normal use, there is a slight win (very very small difference with small cycles).

So in the ideal theory, the lower the SOC, the less degradation. Reducing average SOC would reduce the calendar aging and the cyclic aging would still be very low, resulting in lower total degradation.

But as there in real lifevus no noticable difference between 30-55% SOC, it do not matter much if the battery is at 30% or 55%.

I did choose 55% for a couple of reasons, and also did choose to charge every day for a couple of reasons.

The first thing was to try to reduce the degradation without making it awkward to own a EV.
Next was that I saw there would be such small difference if I always stuggled to have it at very low SOC, for example not charging on saturday morning, as the car might not be driven much over the weekend. The result from always having it at low SOC would be a very impaired possibility to use the car ad hoc, for a almost not measurable reduction in degradation. In my eyes, not worth it.

I would say (again) that its easy to accomplish some 90% of the lowest possible degradation and still be able to use the car without limitations:

-Do not charge more than needed until the next charge. (Can be any setting between 50-100% that is needed until next charge).
-Charge often. This reduces the needed SOC level above. Daily is recommended.
-Charge late, that is = shortly before the drive.

From the above, if we do not need much 50% would be the lowest setting. But as we can increase to 55% (for NCA), 60% (for NMC) and 70% (for LFP) this settings offer the best range without actually making a noticable difference to the lowest possible settings.

I had a 1 1/2 year average SOC of 35.46% despite always charging to 55% every dag except when more was needed. This was accomplished by charging in the morning before the drive.

Which of the two below would be better for the battery?

I hope this answer makes it easy:
It really doesnt matter much. Choose the one that feels best for you.

*) We can se that it’s virtually the same between 30-55% for NCA.

Below, the resulotion is low, there is no measurements shown at 30% so the line hides the real curve between 20-40%.
But we can see the flat part between 40-60%.
Most probably it is the same between 20-40% as the two research reports above show.

 

[melvladimir]

I don't get it... This is storage degradation, but what about active use degradation? When power usage is more than 50%: is it better with SoC 50% or 80%?
And graphs said that, for example, 5% SoC is nice, but I saw warnings "Do not drop SoC below 20% too often or it will lead to degradation".

 

[E90alex]

What do you mean when power usage is more than 50%?

 

[melvladimir]

What do you mean when power usage is more than 50%?

Fast launch/speeding, accelerator pedal pressed down to the floor, or when speed above 180 km/h /112 mil/h

 

[E90alex]

There’s no problem with doing any of that at 50%. You might get slightly less power than at 80% but it’s not really noticeable enough to make a difference in daily use.

 

[flixden]

There’s no problem with doing any of that at 50%. You might get slightly less power than at 80% but it’s not really noticeable enough to make a difference in daily use.

Batteries experience a significant voltage dip when drawing a lot of current, like for example during hard acceleration. I am guessing that's what Vlad refers to. The question is: at what point does it became damaging, meaning that the voltage drops low enough for the battery to experience accelerated degradation of some sort.
I have no idea though what the answer is, or even if a drastic voltage drop can cause damage. Haven't seen it discussed much here either ...
So ... Good question asked by Vlad, if you ask me!

 

[AAKEE]

I don't get it... This is storage degradation, but what about active use degradation? When power usage is more than 50%: is it better with SoC 50% or 80%?

Do not think”storage degradation.”

Calendar aging happens all the time.
To make it easy, calendar aging is often described as the non using periods and cyclic aging the period when the battery is in use, but in plain english, calendar aging happens all the time, even when cycling the battery.

The average car is driven some 10.000-20.000km each year. At an average speed of 50km/h this takes about 300 hours or so.
Charging for this is about 3000kWh, so that is some 500hours with 6kW charging power.
The sum is 800hours of use each year.
Each year has 8760hours or so, so then there is still about 8000 hours when the battery is not in use ( the car is in use/charging 9% of the time in this example, making it not in use/storage for 91% of the year. How you like to see it is up to you, in real life you have calendar aging either 8000 or 8760 hours each year.

The other part is cyclic degradation.
For most users this is like 0.5-1% per year, or less. It is not a big part if the loss, and it actually reduces when using small cylcea at low SOC, so no problem there.

Lower SOC is always better for reducing degradation.

- Do not charge more than you need until the next charge. (But use a personal margin to not get range anxiety.)
- Charge often. Charging often reduces the
“Needed charge level” per the above statement.
-Charge late. This reduces the time with high SOC, this reducing the calendar aging.

Above statements make it clear that 80% is not better if using 50% of the charge.
But if you need a 30% margin to feel happy, use it!
( I would charge to 55-60% and aim for 5-20% in the end of the day).

I use about 50% for my trip to work. I can not be late so I have a small margin for rerouting for accidents etc, so I in general
Aim to arrive at about 7-15-20%. Mostly
Have had the car parked at about 15% during the work week.

And graphs said that, for example, 5% SoC is nice, but I saw warnings "Do not draw SoC below 20% too often or it will lead to degradation".

The warnings you saw was not Teslas warnings.
It was myths.

Low SOC causes lower calendar aging and also cycles at low SOC causes low cyclic aging.

I guess you have seen the graphs from calendar aging, and undestood those?
Low SOC = low degradation, even down to
0%.
A usual issue is that people think 0% is completely dead. Its not. 0% is the cell voltage Where the manufacturer says to stop the discharge, which is a safe level
For the battery.
Our Tesla has a 4.5% buffer below 0% on the screen so when we read
0% it is actually about 4.5% in the battery which is very safe for the battery. If parking at
0% or below it os wise to charge amyway, because if the BMS is wrong on the SOC the car might shut down and may need a new 12v battery if left without charing.
( the lithium battery still is very safe).

 

[AAKEE]

Batteries experience a significant voltage dip when drawing a lot of current, like for example during hard acceleration. I am guessing that's what Vlad refers to. The question is: at what point does it became damaging, meaning that the voltage drops low enough for the battery to experience accelerated degradation of some sort.
I have no idea though what the answer is, or even if a drastic voltage drop can cause damage. Haven't seen it discussed much here either ...
So ... Good question asked by Vlad, if you ask me!

Tesla has a low voltage limit that limits the power to keep the voltage drop within safe limits. For example Tesla used quite high allowed lowest voltage initially on the M3P refresh I had. At low SPC ot was very slow, and it was the battery voltage that had a low floor limit that made the power low at low SOC. They changed it later, but its still possible to accelererate hard worh different SOC and see the low voltage limit with Scan my tesla.

The cells themself has a low voltage limit of 2.5v/cell and that is way below 0% and where the car shuts down.

So the car protects the battery from too high power demands at low SOC.

Still, from using lithium batteries in applications that do not protect the battery from low SOC and high power I know that this could be bad so the spinal cord tell me
not to use very much power below 20%.
I know the car would protect itself but still I am carefull below 20%, in the same
way I do not floor the pedal woth a cold ICE engine.

 

[flixden]

Tesla has a low voltage limit that limits the power to keep the voltage drop within safe limits. For example Tesla used quite high allowed lowest voltage initially on the M3P refresh I had. At low SPC ot was very slow, and it was the battery voltage that had a low floor limit that made the power low at low SOC. They changed it later, but its still possible to accelererate hard worh different SOC and see the low voltage limit with Scan my tesla.

The cells themself has a low voltage limit of 2.5v/cell and that is way below 0% and where the car shuts down.

So the car protects the battery from too high power demands at low SOC.

Still, from using lithium batteries in applications that do not protect the battery from low SOC and high power I know that this could be bad so the spinal cord tell me
not to use very much power below 20%.
I know the car would protect itself but still I am carefull below 20%, in the same
way I do not floor the pedal woth a cold ICE engine.

I am 100% with your spinal cord here!
What you are saying makes perfect sense!

 

[ohyeahplayer]

Hi! New here and have owned a new M3SR for about a week and a half. Still learning... learning a lot. I'm charging up to 100% at home via my mobile charger. It seems like this is not the preferred or popular move.

I've read through this thread and a handful of others but am still struggling to get a clear answer. Can I safely charge to 100% with my 2023 M3SR, or am I inadvertently hurting myself by doing so? Thanks.

 

[AAKEE]

Hi! New here and have owned a new M3SR for about a week and a half. Still learning... learning a lot. I'm charging up to 100% at home via my mobile charger. It seems like this is not the preferred or popular move.

I've read through this thread and a handful of others but am still struggling to get a clear answer. Can I safely charge to 100% with my 2023 M3SR, or am I inadvertently hurting myself by doing so? Thanks.

The 2023 model 3 RWD (“SR) is the LFP version, right?

You do not kill the battery by charging to 100%. Its the recommendation from Tesla.
If charging to 100% mostly you will have a predictable degradation from this, not that much but depending on the climate etc. about 4-5% the first year of so. Following years will have lower degradation.

If you decide to keep the battery at 70% or below for most of the time, the degradation will be about cut by half.

 

[M3INMDJON]

Hello all, first post and just purchased my M3 back in May. Loving it so far, but this has also confused me. Whenever I charge my car, I get a message saying I should charge to 100% at least once a week, yet, I'm seeing more folks saying to charge to roughly 80%.