What Percent is Your Tesla Charged to While at Home?

[OxBrew]

I charge to 55% daily and bump it up as high as 100% when I need it. I usually charge as late as possible to minimize the time spent at high SoC.

Same, exactly. Plug in every night below 40°F, sometimes skip a few days if we're above 50%.

We drive every day, 4 to 30 miles ish. Weekends we usually head to cabin, 80 miles away, charge to 75% the night before, easily make the round trip.

Every 6 weeks ish we take a longer road trip, bump it to 100% a couple hours before leaving, after charging to 90-95 the night before.

Last year we did about 38% Supercharging. At 25k total miles, battery degradation is at about 4%. (freezes all winter, which I think has more to do with battery deg than our charging habits).

 

[CleanDemon]

For non-LFP, Elon says to charge it to 90%. But what would he know..?

 

[E90alex]

Its not about how often you drive per week, since the car is always plugged in. Its how much range you want to have at any given moment. Battery age, not charge level, is going to be the biggest factor in how much range your battery pack can maintain per charge. Its seems strange to deprive yourself the range that you bought the car for in the first place. Especially if its to keep range as high as possible.

Deep discharges hurt the pack more than maintaining 90 percent ever will. Play it safe and charge to 90!

Calendar aging is affected by both SOC and temperature. @AAKEE has many posts about this in various threads with data to back that up.

 

[denstl]

I plug in at home every night and charge to 80% That is what the dealer told me to do. Most days I do not drive very far so probably at 70% at end of day. I would say it takes less than 30 minutes each night.

 

[AAKEE]

Its not about how often you drive per week, since the car is always plugged in. Its how much range you want to have at any given moment. Battery age, not charge level, is going to be the biggest factor in how much range your battery pack can maintain per charge. Its seems strange to deprive yourself the range that you bought the car for in the first place. Especially if its to keep range as high as possible.

Thats not right.

Calendar aging is like [SOC x Temp x time]

Look at the NCA cells (panasonic NCA, like teslas), most common in Teslas. You can see that the degradation cut in half between 55 to 60%. In reality there is a fixed point at about 57% for a new NCA battery. Aging moves this point slightly upwards but fast charing moves it down.
The calendar aging is dependent on swuare root of time, so for exampe using 80-90% charge ands driving only 20% will keep the SOC on the high side. After four years(48 months) you will have a calendar aging of: 5 x square root(48/10)= 11% cyclic aging.

Deep discharges hurt the pack more than maintaining 90 percent ever will.

No, you wont.

If you do full cycles, like 100% to 0%, the same cells as in the picture above will degrade like this:
The chart marked 4.2V is run 100% to 0%, thats the true 0% = 4.5% below Teslas 0% on the screen. In a Tesla this is about the time when a Tesla already has stopped running and is shutting down.

You get about 800 full cycles, for 0.5A-0.7A which is 0.2-0.3C or about the driving power of a tesla.
800 cycles 100-0% would be 800 x 400km = 320.000 km. During this cycles, 25% capacity is lost.
A normal car does about 10-20K km per year. Lets say 20K then. This is 50full cycles each year. The degradation for these very big cycles is 50/800*25 = 1.56% each year, so 6.25% for four years.

For these four years of 80% SOC, with large cycles calendar aging would be 11% and cyclic aging 6.25%
With smaller normal cycles, the annual cyclic degradation is only a fraction so most 4 year old cars charged to 80-90% will have about 11-12% total degradation, of which 11% is calendar aging.

 

[AAKEE]

This is a calendar aging test of actual Tesla model S cells from a Tesla used in 6 months since new.
Its a very clear increase in calendar aging at high soc. More at 80 than at 100.

The test for the first 250 FCE supports the same rate of degradation as in the first example above.

 

[SigNC]

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

This isn't really ideal and I think the manual says to charge to 100% at least once a week. The 100% charge really is to let the BMS calibrate as the voltage change in a LFP pack isn't as dramatic as NMC. Even LFP i'd not charge to 100% every night and leave it sitting when there is no real need for it.

 

[Cupcake & Dino]

2016 MX 75D charge to 90% gives me 210 miles. I will wait 2-3 days to do it again. Work, dog park, store. I do use the schedule for the car, that is nice for when I leave for work the battery is ready for full re-gen and again when I head home from work.

 

[Ther0ck]

This isn't really ideal and I think the manual says to charge to 100% at least once a week. The 100% charge really is to let the BMS calibrate as the voltage change in a LFP pack isn't as dramatic as NMC. Even LFP i'd not charge to 100% every night and leave it sitting when there is no real need for it.

Until Tesla comes out with valid data, I'll keep doing what my car/manual tells me to do, keep it at 100% and always be charging.

Also it's a lease

 

[Resist]

My 2018 started with 310 EPA-rated miles. It still has 310 EPA-rated miles.

I have a difficult time understanding how an almost 5 year old Model 3 still gets the 310 mile rated range. It would have to lose some battery health just due to the age. My 2018 Long Range Model 3 is down to around 285 miles of range and I've never abused the battery. But if you have some magical trick, I'd like to duplicate it on my car.

 

[Spinkick]

Thats not right.

Calendar aging is like [SOC x Temp x time]

Look at the NCA cells (panasonic NCA, like teslas), most common in Teslas. You can see that the degradation cut in half between 55 to 60%. In reality there is a fixed point at about 57% for a new NCA battery. Aging moves this point slightly upwards but fast charing moves it down.
The calendar aging is dependent on swuare root of time, so for exampe using 80-90% charge ands driving only 20% will keep the SOC on the high side. After four years(48 months) you will have a calendar aging of: 5 x square root(48/10)= 11% cyclic aging.
View attachment 934950

No, you wont.

If you do full cycles, like 100% to 0%, the same cells as in the picture above will degrade like this:
The chart marked 4.2V is run 100% to 0%, thats the true 0% = 4.5% below Teslas 0% on the screen. In a Tesla this is about the time when a Tesla already has stopped running and is shutting down.

You get about 800 full cycles, for 0.5A-0.7A which is 0.2-0.3C or about the driving power of a tesla.
800 cycles 100-0% would be 800 x 400km = 320.000 km. During this cycles, 25% capacity is lost.
A normal car does about 10-20K km per year. Lets say 20K then. This is 50full cycles each year. The degradation for these very big cycles is 50/800*25 = 1.56% each year, so 6.25% for four years.

For these four years of 80% SOC, with large cycles calendar aging would be 11% and cyclic aging 6.25%
With smaller normal cycles, the annual cyclic degradation is only a fraction so most 4 year old cars charged to 80-90% will have about 11-12% total degradation, of which 11% is calendar aging.
View attachment 934951

Thanks for the data.

Calendar aging is affected by both SOC and temperature. @AAKEE has many posts about this in various threads with data to back that up.

Why reduce your SOC by so much to limit wear so you keep range capacity you arent using in the first place? Heat is kept down simply by limiting how often you supercharge. Cant help time.

 

[KenC]

I have a difficult time understanding how an almost 5 year old Model 3 still gets the 310 mile rated range. It would have to lose some battery health just due to the age. My 2018 Long Range Model 3 is down to around 285 miles of range and I've never abused the battery. But if you have some magical trick, I'd like to duplicate it on my car.

As I wrote, initially, I've kept my nightly SOC to 60%, actually 58%. SMT says my battery still has 76.4kWh, out of 77.8kWh. So, some degradation, but still in the upper buffer. My car lives outdoors, so I don't baby it or anything. I do charge to as high a level as necessary while roadtripping, but I generally don't leave it sitting at high SOCs, nor do I charge it up before leaving for a roadtrip since it generally means only saving a few minutes at my first supercharger stop. So, the only thing I am doing is keeping it charged to 60%, or rather 58%, at night.

I turned off the Stats app in the winter, so there's a big gap, but obviously still 310miles of EPA-rated range.

Clearly an outlier. I'm the asterisk in the Teslalogger chart.

And the same with Recurrent's chart. For whatever reason, my car is a couple deviations outside of the normal range.

 

[Resist]

As I wrote, initially, I've kept my nightly SOC to 60%, actually 58%. SMT says my battery still has 76.4kWh, out of 77.8kWh. So, some degradation, but still in the upper buffer.

I still have a hard time believing a 2018 Tesla Model 3 still gets 310 miles of range. And where did you get the 77.8 kWh from? Everything I've read said the 2018 Model 3 has a 75 kWh battery. But even if the car was put into storage, with the optimal battery state and perfect charge rate, it would still have more degradation than yours, which is driven on a normal basis. I'm not calling you a liar, but something isn't adding up. I've never heard of anyone else not lose range after almost 5 years of use. If your numbers are true then you should contact Tesla so they can study it and advise everyone on how to get the same results. This would be front page news for Tesla's everywhere.

 

[jjrandorin]

I still have a hard time believing a 2018 Tesla Model 3 still gets 310 miles of range. And where did you get the 77.8 kWh from? Everything I've read said the 2018 Model 3 has a 75 kWh battery. But even if the car was put into storage, with the optimal battery state and perfect charge rate, it would still have more degradation than yours, which is driven on a normal basis. I'm not calling you a liar, but something isn't adding up. I've never heard of anyone else not lose range after almost 5 years of use. If your numbers are true then you should contact Tesla so they can study it and advise everyone on how to get the same results. This would be front page news for Tesla's everywhere.

@KenC has provided proof in screenshots in more than one thread about the state of his battery, so you need to ease up a bit on the "I have a hard time believing it, it isnt adding up, etc". The easiest explanation would be that his car may have had a slightly larger buffer than others, and he also explained very clearly what he does (and his car sits outside in the cold, as well).

See @AAKEE 's posts for more detail on why the cold matters, and why sitting at 50% might matter if thats something you want to do.

 

[E90alex]

Thanks for the data.

Why reduce your SOC by so much to limit wear so you keep range capacity you arent using in the first place? Heat is kept down simply by limiting how often you supercharge. Cant help time.

I may not need to use the full range everyday but I will use it if I take a longer trip.

The heat in question is average temperature of the battery, which for majority of the time is in “storage” as in the car is parked. That temperature you largely can’t control since it’s based on where you live. Time you also can’t control. The only thing you can really control in terms of calendar aging is average SOC.

 

[Rottenapplr]

I think it depends on a number of factors - ambient temperature being the major one I’d assume

All I know is that if I charge to 80%, my pump potentially runs for hours

At 75, it’s off once the cycle completes

What year do you have?

 

[KenC]

I still have a hard time believing a 2018 Tesla Model 3 still gets 310 miles of range. And where did you get the 77.8 kWh from? Everything I've read said the 2018 Model 3 has a 75 kWh battery. But even if the car was put into storage, with the optimal battery state and perfect charge rate, it would still have more degradation than yours, which is driven on a normal basis. I'm not calling you a liar, but something isn't adding up. I've never heard of anyone else not lose range after almost 5 years of use. If your numbers are true then you should contact Tesla so they can study it and advise everyone on how to get the same results. This would be front page news for Tesla's everywhere.

LOL

Have you heard of SMT? ScanMyTesla? That's their best guess of the actual capacity of our batteries from 2018. Currently, the batteries are around 82kWh, so mine didn't start especially large.

Maybe the trick is mine came home delivered in cold December, with zero charge. Yep, zero.

Anything else you'd like me to answer?

I've been posting my data, which doesn't add up, but doesn't make me a liar, here ever since I placed my order, which was in August of 2018. I still remember in 2019, people telling me in posts, that my range would start dropping in 12 months. Hasn't happened yet.

 

[AAKEE]

Why reduce your SOC by so much to limit wear so you keep range capacity you arent using in the first place?

Not many use all range each day.
Most use quite little of the range daily and more on occations.

I do not think there is anyone teaching to charge to a lower SOC than whats needed.
When at the ATM I guess you only take oute the amount you need plus a margin, and not all your savings?

It is possible to cut the degradation in half, or more by using the low SOC strategy, even if you need more than 55% SOC.

This drives calendar aging: [Time x SOC x temp]
-We can cut the time at high SOC by charging late. That means having the charge finished just before the drive.
-We can reduce the average SOC by charging often, and as low as possible (inlcude a personal margin for range anxiety).
-We can often not do anything against the tempersture. Store in a insulated garage during hit days, or at least not keep the car in the sun. Heat causes high degradation at high SOC so we can conquer the heat by having low SOC at hot periods.

To sum things up:
-Charge late
-Charge often (smaller cycles and lower mean SOC)
- Do only charge to the SOC you need.

Heat is kept down simply by limiting how often you supercharge. Cant help time.

Heat from a supercharge will not change the calendar aging much. Most people drive after the supercharge and elevated temperatures is not bad for cyclic aging.
For cyclic aging the cell temp is best at 25C or above, up to 40C or so.
For calendar aging, one supercharge may increase the cell temp about 1/2 to 1 hour before, and 1/2 to 1 hour during the charge and one hour after the charge. Its 1.5 to 3 hours in total. 3/8760 of one years calendar aging. Not a factor.

 

[AAKEE]

I still have a hard time believing a 2018 Tesla Model 3 still gets 310 miles of range. And where did you get the 77.8 kWh from?

(The question about “75kWh” shows you have a few things to learn. Whats good to know, all the information you need is here on TMC)

For Ken’s M3, battery size was 77.8kWh when new.
The range doesnt drop until the capacity is below about 76kWh.
This gives a possibility to have small degradation and not loose range.

Keeping low SOC in average (not above 60%) and living in a cold place will keep the battery capacity high.

Using this data, I have made formulas for calculating this, my car should be at about 78.75kWh today, and if the miles driven (cycles) is included it should be around 78kWh.

The latest picture capturing the Nominal Full Pack (a value taken directly from the cars BMS) shows 78.9kWh.


To sum it up, degradation is foreseeable from the research data of calendar and cyclic aging and the rate can be kept very low by using low SOC.

 

[Spinkick]

Doing all of that, what percent of degredation do you think you'd save in that battery pack over lets say, 3 years? someone charging to 90 percent in a cool climate, vs someone charging to say 60 percent? I we thinking a 5 percent savings?