What Percent is Your Tesla Charged to While at Home?

[AAKEE]

A Tesla with a LFP Battery use 100% settings to reset the charging level counter.
This is used because the car has hard to measure the state of charge in the battery.
Charging full gives a fix point = 100% sure about having 100% state of charge.

With no full charges for long time there is a increasing uncertainty about what state of charge the battery has.
In these cases the car put more of the battery capacity as buffer below 0% on the screen, reducing the practical range we can drive.
Charge to 100% at least once a week makes sure that the most part of the available energy in the battery is usable.

Reading the manual is much better than reading charging tips on forums.
If you follow the very few and simple tips in the manual the battery will hold very long and the car will work fine. Theres no need for anything else.


The 80% or 90% being the best charging thing is a forum myth.

The lower the state of charge, the slower the battery degrade. So in principle the lowest charging setting that cover the needs for range until next charging session will be the best.
Also charging late (shortly before the drive), so the time at high SOC is reduced is good.

There is a possibility to reduce the degradation with about 50% if that is a goal.

 

[M3INMDJON]

A Tesla with a LFP Battery use 100% settings to reset the charging level counter.
This is used because the car has hard to measure the state of charge in the battery.
Charging full gives a fix point = 100% sure about having 100% state of charge.

With no full charges for long time there is a increasing uncertainty about what state of charge the battery has.
In these cases the car put more of the battery capacity as buffer below 0% on the screen, reducing the practical range we can drive.
Charge to 100% at least once a week makes sure that the most part of the available energy in the battery is usable.

Reading the manual is much better than reading charging tips on forums.
If you follow the very few and simple tips in the manual the battery will hold very long and the car will work fine. Theres no need for anything else.


The 80% or 90% being the best charging thing is a forum myth.



There is a possibility to reduce the degradation with about 50% if that is a goal.

This makes A LOT of sense. I posted earlier that whenever I plug my car in, I get a message that I should charge to 100% once per week.

 

[melvladimir]

Most probably it is the same between 20-40% as the two research reports above show.

I want to ask again if I understand this correctly: it is better to charge 100% than 80%? Or this is for old Panasonic NCA and for LG another pattern?
Also, I saw this pic:

This pic is a teaser.

And here we have another pattern.

A little bit of background to my question: winter is coming and it is a high probability that russians will terrorize us shelling power plants as last winter, so the electricity will be available at random and I will have to keep high SoC.
So, what is the highest preferable SoC level for an NCA battery under these circumstances?

 

[AAKEE]

I want to ask again if I understand this correctly: it is better to charge 100% than 80%? Or this is for old Panasonic NCA and for LG another pattern?
Also, I saw this pic:

The first picture is a 2170 NCA cell of a “non disclosed brand”. We do not know the brand, but I would guess there is a reason for not disclosing the brand: possibly/probably a Tesla 2170 cell.(more or less all other research reports put the details for the battery cells out.)

We do not need to draw the conclusions from that picture too hard. I mainly use it to show the fanatics that continue to say that 100% is very bad for the battery but 80 or 90% is the best. (Which is not true at all).
I have a picture to throw out where actual Tesla model S cells from a almost new car was used, they showed a similar pattern as that picture. Actuall Tesla cells and 80% was the worst, when only looking at capacity loss.

The takeaway if you ask me is not that 100% is prefered over 80%, but that 80% wear about as much or slightly more than 100%.
100% causes a higher increase in internal resistance which isnt perhaps very important to the average user but for a performance car where we like to keep the power output over time, we should try to keep the internal resistance low.

And here we have another pattern.

This picture is panasonic 18650 NCA, closely related to Tesla model S cells but probably not exactly the same.
Different cells might behave slightly different.
Different test setups might give slightly different results.
Different test might mask some battery behaviours, depending on how the setup and measurement etc is made.

This picture and a few others is a good average to remember, even if the details for a specific battery might look a little different.
Remember that:
Higher SOC causes higher calendar aging.
Higher Temperature causes higher calendar aging.

A little bit of background to my question: winter is coming and it is a high probability that russians will terrorize us shelling power plants as last winter, so the electricity will be available at random and I will have to keep high SoC.
So, what is the highest preferable SoC level for an NCA battery under these circumstances?

I guess you will not have the car in a very warm place?
If it is outside, look at the prefered graph and imagine a 10C line that is about only 50% as much degradation as the 25C graph. —-> meaning you can use 80-90-100% with the same calendar aging as 55% in a normal summer day at 25C.
If you have the car outside and it is cold the calendar aging will be even less and almost “stopped”.

Feel free to use the SOC you think is best for your situation. Even 100% is not even close as bad as many people think. In cold weather you can do it whenever you need. If you stay at 90% you still are within the former Tesla recommendation, so that is OK too.

If you need to use higher SOC now, and maybe it is a much better situation the next winter, and you use lower SOC then, the battery is kind of protected from the earlier “extra degradation” so then the degradation will be slower that winter than it had been otherwise.
(The calendar aging is mostly Solid Electrylote Interphase and it also acts as a barrier for further SEI build up. Thats the reason for the calendar aging to drop of by time.)

So to sum it up, There will not be a danger for the battery. Do as you need and the battery thing will sort out anyway. Stay safe!

 

[johnny_cakes]

If you need to use higher SOC now, and maybe it is a much better situation the next winter, and you use lower SOC then, the battery is kind of protected from the earlier “extra degradation” so then the degradation will be slower that winter than it had been otherwise.
(The calendar aging is mostly Solid Electrylote Interphase and it also acts as a barrier for further SEI build up. Thats the reason for the calendar aging to drop of by time.)

This comment is very interesting. If I understood correctly, then in theory when comparing 2 batteries, then the battery that's been degraded more in the first few years will degrade less in the subsequent years, even if subjected to the same conditions in subsequent years? For example:

Battery A

• 5% degradation after 1 year
• Year 2 is stored at 50% SoC, 25C

Battery B

• 10% degradation after 1 year
• Year 2 is stored at 50% SoC, 25C

Does Battery B degrade less than Battery A in year 2?

 

[flixden]

I want to ask again if I understand this correctly: it is better to charge 100% than 80%? Or this is for old Panasonic NCA and for LG another pattern?
Also, I saw this pic:

And here we have another pattern.

A little bit of background to my question: winter is coming and it is a high probability that russians will terrorize us shelling power plants as last winter, so the electricity will be available at random and I will have to keep high SoC.
So, what is the highest preferable SoC level for an NCA battery under these circumstances?

Yeah, comparing the two graphs is interesting (and confusing as the data shown does not quite agree).
In the first graph, it shows a lower calendar aging at an SOC of 100% than at an SOC of 50%, if I read the graph correctly. That's against most statements that I have seen here and anywhere else, in fact.

 

[hey kupo]

Most often between 20-35%. We only need to charge every few days, usually an hour (~13%) during peak solar. Our most frequent longer trips only require about 20% round trip. Not much need to go above 50%.

 

[EVolVEr]

90%

Will be 80% in the future.

 

[WhtOnWhtTsSY]

As per Tesla manual, always be charging and at 100% (LFP).

keeping it at 100% constantly degrades the battery faster than keeping it at a lower state of charge which is easier on the battery chemistry. even LFP. keeping it plugged in at the lowest possible SOC is better for the battery. although they want you to charge it to 100% once a week to keep the accuracy up.

 

[syncword]

I'm at the minimum 50% for now because the best info I've yet read is sitting at a lowish SoC - particularly in my hot climate is a happier place for the battery, including LFP. A 20-30 to 50% SoC cycle is so far looking typical for almost all the daily drives. For a longer trip the next day it's easy enough to temporarily bump it higher overnight. I'm after minimum degradation particularly in this first year. (Took delivery of the '23 RWD just over two weeks ago.)

Not only because they're more expensive, I plan to steer clear of superchargers when possible. Home charging is about 1/3 the kWh rate, and there are still plentiful free 6-7 kW L2 chargers in the area e.g. when shopping, netting a ~30 mi/hr rate. Recently coming from a PHEV I became proficient in making efficient use of its < 8 kWh usable battery, and the same skills should help here.

 

[chinney]

We charge to 90% and then let it decline to about 30% before recharging. That is for the battery on a now 3-year old Model 3 LR. The range on the battery has held out pretty well during that time. We have lost about 6 or 7 % since purchase, almost all of that in the first year. We don't using Superchargers all that often nor do we charge to 100% very often at all.

 

[dloomis]

70% based on the feedback from Dr. Dahn in this video.

 

[Teetoogrn]

I used to charge it to 75%, but Iowered it to 60%. If I’m going on a road trip, I’ll increase it.

 

[pdx_m3s]

Summer = 50%
Winter = 65%
Trips = as needed

2019 SR+ with Panasonic cells.

 

[flixden]

70% based on the feedback from Dr. Dahn in this video.

He says charge to 70%, then discharge to 45% and repeat. Also not quite in agreement with what's usually recommended here. Makes me wonder if anybody really knows ...

 

[stopcrazypp]

He says charge to 70%, then discharge to 45% and repeat. Also not quite in agreement with what's usually recommended here. Makes me wonder if anybody really knows ...

There isn't a set "correct" SOC to charge to given usage patterns vary for people (how much they travel before charging and how much margin they want to leave).

It's interesting however that there are tests that show storage at 80% is worse than at 100% (while others show 100% is slightly worse than 80%). This makes suggestions to err on the side of less SOC less straightforward.

It doesn't make a lot of intuitive sense however and I wonder what the science behind that is (or if it is a quirk of the testing methodology).

 

[KenBlub]

2023 Model 3 RWD here. I charge to 100% every 2 week’s before my longest drive and 50% as needed the rest of the time. I use off peak charging so my battery charges just before I leave. This has the LFP battery

Question - When I charge to 100% how long should I have the battery sit before I leave? Stop changing at 7:00am if I’m leaving at 7:15 or stop charging at 6:00 or 5:00 on those days I’m going to 100%. Thanks

 

[BigNick]

2023 Model 3 RWD here. I charge to 100% every 2 week’s before my longest drive and 50% as needed the rest of the time. I use off peak charging so my battery charges just before I leave. This has the LFP battery

Question - When I charge to 100% how long should I have the battery sit before I leave? Stop changing at 7:00am if I’m leaving at 7:15 or stop charging at 6:00 or 5:00 on those days I’m going to 100%. Thanks

Early in the morning (when there is less heat) an occasional "rest' at 100% for an hour or two shouldn't do much harm.

But if you really want to minimize degradation, I'd schedule those 100% charges for shorter times between "charge complete" and "start of drive" during summer months like the 7:00/7:15 example you gave.

 

[KenBlub]

Early in the morning (when there is less heat) an occasional "rest' at 100% for an hour or two shouldn't do much harm.

But if you really want to minimize degradation, I'd schedule those 100% charges for shorter times between "charge complete" and "start of drive" during summer months like the 7:00/7:15 example you gave.

Thank you. I guess I was really asking if there was any additional balancing that takes place after charging hits 100% and it seems like “no”. If that’s the case, no reason to have it sit at 100% longer than necessary.

 

[WhtLghtning]

I have been charging at work which gets me 50% in 8 hours, around that. So I will wait till the car runs down to 30% then set back to 80% at work. I will do this every other day. I never let the car sit below 30% overnight.