What should my ideal charge percentage be?

[Leeclanual]

The manufacturer (Tesla) does not recommend to charge to 90% specifically.
The slider is 50-90% and 90% is the maximum “daily” charge.

There is no Tesla recommendation to better charge to 90% than 80%.

Tesla does not use the recommendation to minimize degradation. Its most certain a combo of acceptable degradation and having a useble range.

Lowest degradation will be at low SOC, but if Tesla did recommend that we should charge to 50% or even lower they probably would get sued for selling a 300mile car that only can be driven 150miles, or less.

80-90% SOC during a lot of time will degrade the battery noticeble. 80-90% is causing about the same calendar aging as 100% SOC.

The car will (most probably) stay inside the >70% capacity after eight years anyway.

Calendar aging lessens with time and is quite small after about five years.

So using 80-90% SOC is not a problem condidering the warranty etc.

But if someone is worried about degradation, 80-90% will not cause the lowest degradation possible.

Using as low SOC as possible and charging often, preferably just before the car is to be driven could cut the degradation in half.

This means having 5% instead of 10% or 10% instead of 20% after some years.
For some it doesnt matter, for some the lesser loss of range is important.

Others can not charge at home and do not have the possibility to use low SOC or charge just before the drive. In this case, we need to accept the degradation as a normal sequence of the charging habits.

So I pickup my new MS on Tuesday… what % should I use? How often (%, daily, etc) should I plug it in during a normal week? I don’t regularly do long daily trips or road trips… generally a daily driver within 30-40 miles from home (golf, shop, restaurants). Thoughts to keep this battery healthy? I just sold my M3 after 4 years… charged it to 85% a couple times a week… charged it to 95% when going on a road trip. Rarely used SCs and my range over the years dropped from 307 to 290.

 

[tesluv108]

The manufacturer (Tesla) does not recommend to charge to 90% specifically.
The slider is 50-90% and 90% is the maximum “daily” charge.

There is no Tesla recommendation to better charge to 90% than 80%.

Tesla does not use the recommendation to minimize degradation. Its most certain a combo of acceptable degradation and having a useble range.

Lowest degradation will be at low SOC, but if Tesla did recommend that we should charge to 50% or even lower they probably would get sued for selling a 300mile car that only can be driven 150miles, or less.

80-90% SOC during a lot of time will degrade the battery noticeble. 80-90% is causing about the same calendar aging as 100% SOC.

The car will (most probably) stay inside the >70% capacity after eight years anyway.

Calendar aging lessens with time and is quite small after about five years.

So using 80-90% SOC is not a problem condidering the warranty etc.

But if someone is worried about degradation, 80-90% will not cause the lowest degradation possible.

Using as low SOC as possible and charging often, preferably just before the car is to be driven could cut the degradation in half.

This means having 5% instead of 10% or 10% instead of 20% after some years.
For some it doesnt matter, for some the lesser loss of range is important.

Others can not charge at home and do not have the possibility to use low SOC or charge just before the drive. In this case, we need to accept the degradation as a normal sequence of the charging habits.

Wondering if you are anyone else cares to comment on the Tessie app stating my battery health is 100%. This seems impossible to me since the car was built in 11/2015. Does anyone think this is just a measurement error by the Tessie app? 81.9 usable kwh doesn’t seem like zero degradation on a 90kwh pack.

 

[tesluv108]

So I pickup my new MS on Tuesday… what % should I use? How often (%, daily, etc) should I plug it in during a normal week? I don’t regularly do long daily trips or road trips… generally a daily driver within 30-40 miles from home (golf, shop, restaurants). Thoughts to keep this battery healthy? I just sold my M3 after 4 years… charged it to 85% a couple times a week… charged it to 95% when going on a road trip. Rarely used SCs and my range over the years dropped from 307 to 290.

Imo the 30-60% method is the best from everything I’ve read. Set your max charge to 60% and charge when it drops to 30%. Others have said keep it at 50% min but that’s your choice.

 

[zoomer0056]

Mine started to take a dive suddenly. Lost 7.5% in 16k miles. That sounds hight to me. Initially I used to charge it to 80%, then to 90% per the manufacturer recommendation. I have used fast charges only a few times. Less than 10.

View attachment 864420

From Tesla.com

 

[Fiver]

Imo the 30-60% method is the best from everything I’ve read. Set your max charge to 60% and charge when it drops to 30%. Others have said keep it at 50% min but that’s your choice.

While I mostly agree with this post, I would also recommend at least plugging in (even if not charging) and keeping it close to 50%. Leaving it plugged in will allow you to remotely up the charge limit should you realize you need extra range in the near future. Otherwise you're tromping out to the garage to plug in.

Most of the time if I'm daily driving (using 30-50 miles) I keep my car in the 40-60% zone. I only charge up more when I know I need the range. In a absolute total emergency I still have my 15 year old ICE Subaru.

 

[zoomer0056]

Wondering if you are anyone else cares to comment on the Tessie app stating my battery health is 100%. This seems impossible to me since the car was built in 11/2015. Does anyone think this is just a measurement error by the Tessie app? 81.9 usable kwh doesn’t seem like zero degradation on a 90kwh pack.

Send Tessie a message asking this question.

 

[ReddyLeaf]

So I pickup my new MS on Tuesday… what % should I use? How often (%, daily, etc) should I plug it in during a normal week? I don’t regularly do long daily trips or road trips… generally a daily driver within 30-40 miles from home (golf, shop, restaurants). Thoughts to keep this battery healthy? I just sold my M3 after 4 years… charged it to 85% a couple times a week… charged it to 95% when going on a road trip. Rarely used SCs and my range over the years dropped from 307 to 290.

Imo the 30-60% method is the best from everything I’ve read. Set your max charge to 60% and charge when it drops to 30%. Others have said keep it at 50% min but that’s your choice.

80,000 mi 2015S70D here. I only charge on 120V at home and keep it at 50% and plugged all the time when not driving. Town driving is usually less than 10-20 mi. Most miles are road-trips, driven hard (mountain passes) with SC use, including 4-5x per day. Range has dropped from about 235-240 mi new to 220-225 mi now at 7.5 yr, so less than 10%. For you, I would recommend setting at 55-60%, plugging in every time you return, and always leaving it plugged in until the next trip. If you want to be grid-friendly, or you have solar or TOU pricing, set to charge at that specific time. The battery will last longer when left at an average lower SOC (within reason, certainly above 20%, but the actual number is probably unknown) and an average lower temperature (again, within reason, certainly above 30F, but the actual number is probably unknown). What is known is that high temps (>90F) and SOC (>90%) definitely increases degradation. I don’t worry about temps (can’t park in the refrigerator), but if you’re in a higher temperature area, it would definitely help to park in an air conditioned space.

 

[STS-134]

I don’t worry about temps (can’t park in the refrigerator)

Sure you can: Best Garage Air Conditioners For 2,3,4,5-Car Garage (2022)

That said, if you do this, best to insulate the entire garage, which includes all of the walls, the roof, and of course, the garage door. And you may not put return registers from your home's HVAC system in the garage because there's no intake from the garage and this will cause negative pressure in the living space as air is pushed from the house to the garage and the house cannot become a large vacuum; air will then be sucked in from other areas, including outdoors (inefficient) and possibly down the flue of any gas appliances like water heaters (which is dangerous). If you do this, you must use an entirely separate system (like a window AC unit or mini split) that serves the garage only. I don't have AC in my garage though, because not only is it not energy efficient to cool the garage (think of how much cool air would get lost every time the garage door is opened!), but I don't live in a very hot climate. It did get grotesquely hot in my garage almost 24/7 during the big heat wave a little more than a month ago but that's definitely not the normal weather around here.

 

[AAKEE]

Wondering if you are anyone else cares to comment on the Tessie app stating my battery health is 100%. This seems impossible to me since the car was built in 11/2015. Does anyone think this is just a measurement error by the Tessie app? 81.9 usable kwh doesn’t seem like zero degradation on a 90kwh pack.

I don’t know much about tessie.

I have Scan my tesla and also use Teslafi.

I also do not know much about model S battery sizes, but i know there wasnt always a 100% red thread between the name on the car and the battery pack.

A quick googling showed me “85.8 kWh total capacity, 81.8 kWh usable” on the P90D.

A seven year old battery that have been charged to more than 60% for most of the time at normal temperatures probably has lost 10-13% on calendar aging.

I would expect a degradation of about 10% or slightly more if the car has neen in normal temperatures. A bit more degradation in hot climates.

I guess the BMS is a bit off, if the battery was not recently changed to a new one.

 

[AAKEE]

So I pickup my new MS on Tuesday… what % should I use? How often (%, daily, etc) should I plug it in during a normal week? I don’t regularly do long daily trips or road trips… generally a daily driver within 30-40 miles from home (golf, shop, restaurants). Thoughts to keep this battery healthy? I just sold my M3 after 4 years… charged it to 85% a couple times a week… charged it to 95% when going on a road trip. Rarely used SCs and my range over the years dropped from 307 to 290.

It depends, do you care just a little about degradation or is it not important?
(I guess from the question that you care).
Good practise can reduce the degradation with about 50%, for most people without making it too ankward.

The basics is:
-The lower SOC, the lower the degradation.
-The smaller the cycles the smaller the degradation.

Do not set the charging level higher than you need. 50% is the lowest setting, thats okey*. Better to charge each day than to charge higher.
If you can use scheduled charging to be done just before the departure (or in the morning). This keeps the average SOC low which is good.

*) For NCA-cells like Panasonic, there is a increase in the calendar aging above 55% on screen SOC, so charging to 55% is much better than 60% if the car will stand for time at this SOC.
I use 55% as the standard charging level.

Higher SOC than 55% does not cause any higher calendar aging if the car is driven after the charging so the SOC goes down. Higher SOC cause higher cyclic aging though, so the best is to not use higher SOC then needed (include a safe margin to not get range anxiety of course).

 

[tesluv108]

I don’t know much about tessie.

I have Scan my tesla and also use Teslafi.

I also do not know much about model S battery sizes, but i know there wasnt always a 100% red thread between the name on the car and the battery pack.

A quick googling showed me “85.8 kWh total capacity, 81.8 kWh usable” on the P90D.

A seven year old battery that have been charged to more than 60% for most of the time at normal temperatures probably has lost 10-13% on calendar aging.

I would expect a degradation of about 10% or slightly more if the car has neen in normal temperatures. A bit more degradation in hot climates.

I guess the BMS is a bit off, if the battery was not recently changed to a new one.

But why is it showing no degradation?. I’ll charge again and report back. Keep in mind the pack has .6400 miles

 

[boonedocks]

Having owned 4 Model S' since 2015, having over 75k miles on each before re-selling, I have had non-detectable range loss. Charged daily to 90% for the entire life of each car and alway plugged in when at home.

Anecdotally form my SC they said that watching cars over the years come through that keeping your car plugged in as often as possible, that would be 13+ hours daily for me, has the most dramatic impact on battery degradation. (SC statement not mine) As a side note we only SuperCharge less than 1% of the life of our cars as an average.

Our 2017 Model X75, 63,481 miles w / 22" wheels still has the same battery / milage capacity as when we brought it home. Plugged in at home for 20+ hours a day set to 90% and SuperCharged maybe .5% (almost never but kinda sad considering it has lifetime free SC LOL) of its charging life.

 

[zoomer0056]

Having owned 4 Model S' since 2015, having over 75k miles on each before re-selling, I have had non-detectable range loss. Charged daily to 90% for the entire life of each car and alway plugged in when at home.

Anecdotally form my SC they said that watching cars over the years come through that keeping your car plugged in as often as possible, that would be 13+ hours daily for me, has the most dramatic impact on battery degradation. (SC statement not mine) As a side note we only SuperCharge less than 1% of the life of our cars as an average.

Our 2017 Model X75, 63,481 miles w / 22" wheels still has the same battery / milage capacity as when we brought it home. Plugged in at home for 20+ hours a day set to 90% and SuperCharged maybe .5% (almost never but kinda sad considering it has lifetime free SC LOL) of its charging life.

Are you using the Tessie app? Can you show us the battery health graph?

 

[boonedocks]

Are you using the Tessie app? Can you show us the battery health graph?

No I don't use any app other than the Tesla App.

When I bought my first 2015 85D I had every app I could get / find but over time I lost interest in secondary apps and just use the Tesla App.

 

[zoomer0056]

No I don't use any app other than the Tesla App.

When I bought my first 2015 85D I had every app I could get / find but over time I lost interest in secondary apps and just use the Tesla App.

You can try Tessie for 14days free. It would be nice to compare your battery graph to mine and to the fleet. I think fleet is the total of Tessie users. My graphs are from a Feb 2022 MSLR with 6,500 miles.

 

[David29]

If only we had known...
When I got my car 7 years ago, I either did not see as much guidance (other than Tesla's) about charging, or maybe I did not pay as much attention. The user population was much smaller (just over 100,000 cars sold) and there was probably less unofficial (i.e., non-manufacturer) knowledge about batteries and charging and so on. Tesla said "Always Be Charging" and said nothing about minimizing your SOC (other than to charge above 80 or 90% only for trips), nor did they say to minimize the use of DC charging. And Supercharging was free to nearly every Tesla owner.
Only when some California Superchargers started to get busy did Tesla start to say that SCs were meant for travel away from home, and tried to discourage SC use for daily driving near home. But nothing was said that it was bad for the battery, only that it was meant for travelers away from home.
I live in a condo and had a long delay (nearly a year) in getting my charger setup approved and installed. In view of what was then the very new guidance from Tesla to use SCs only for trips, I asked my Tesla sales rep if there would be any problem if I used the SC to charge until my home charger was installed. He said, no problem. (The SC was only a couple miles from my house.) I was thinking only of "getting into trouble" from abusing the Superchargers, not about any technical reason to minimize Supercharging. It was only a couple of years later, long after I had my home charging installed, that we started hearing about Tesla throttling SC speed on some cars because of "excessive" DC charging.
I assume that my Tesla 70D is throttled, based upon how low my maximum DC charging rate is, but I have never asked Tesla if it is. We do not take too many trips so the inconvenience is simply something we live with.
I am retired and use my car relatively little and probably should have been keeping my battery at a lower SOC than I have. Until this year, I nearly always charged to 70% or so and only infrequently let the battery get below 50%. I have no garage so the car is as hot or cold as the weather and use pre-heating and pre-cooling frequently.
I do not routinely check my battery range, as that necessitates charging up to 100%, which everyone agrees is a bad idea and which we rarely need. I did try to do a basic test of degradation on one longer trip a few months ago, and it seemed to be only 7%, which seems unlikely after 7 years.
In any case, I do not worry about it too much, but I do regret that my battery is apparently throttled because it does make traveling less convenient than I'd like.
Definitely will have this situation in mind, though, as I decide whether or not to keep this car past its 8-year warranty end date.

 

[ReddyLeaf]

If only we had known………I assume that my Tesla 70D is throttled, based upon how low my maximum DC charging rate is………..(battery loss)seemed to be only 7%, which seems unlikely after 7 years…….
battery is apparently throttled because it does make traveling less convenient than I'd like…..

Sounds like we have the same car, with approximately the same degradation, despite vastly different charging profiles. This is actually amazing and a testament to Tesla’s engineering. My S70D was delivered June2015. All batteries degrade over time/use and the charging speeds have been decreased as well (by Tesla programming but it’s due to internal resistance and chemical degradation). My 2011 Leaf was notorious for this, essentially having no regen in winter after about 4 years.

The great thing about Tesla is that we no longer need to supercharge above 50% SOC, like was required back in 2015-2018. Early on I was always charging to 90%, usually 30-40 min, sometimes more than an hour, just to get to the the next SC 150+ mi away. Even today, in the PNW we have larger SC spacings than CA or the East Coast, but it’s manageable.

Now there are superchargers everywhere (around you it seems like they are every 20-30 mi). Charging to 90% is no longer required. So, what I do on my travels is to always arrive at the next SC at about 5% SOC. This allows me to charge at 105-110 KW initially (not much less than my max 115KW back in 2016). Charging does slow faster than the old days, but I usually unplug at about 50% or 50 KW unless busy with something else like a sit down meal. Having SCs 20-30 mi apart allows me to drive faster (arrive at the closer SC) or slower (arrive at the farther SC) as traffic or conditions warrant. Yes, I stop more often, but with age comes the need for more frequent rest breaks.

As an example, my frequent trips between Kennewick, WA and Newport, OR. In 2017 this trip required an hour stop at The Dalles (5-stall V2) and Woodburn (8-stall V2), usually always full due to being the ONLY SCs along the route and on either side of Portland (big Tesla market). Every trip also requires a “coffee removal stop” before either of those locations. Now, there are seven SCs on this route, and I usually stop four times, but for only 10-20 min per stop. Furthermore, the newer SCs are V3s (no pairing issue), at better locations (services and access). So now, this trip is actually faster, more pleasant, and less stressful (especially less ICEing & Tesla overload at a 5-stall SC).

I’m still waiting to upgrade to a new SEXY that charges at 250 KW, but until that time I will continue to enjoy free charging and more frequent stops. My last trip across North Dakota (75mi SC spacing) was so much more enjoyable than the 150mi SC spacing that I experienced across South Dakota and West Texas in years past. I’m looking forward to my next long road trip. However, unfortunately, the number of hotels with 240V charging has not increased as fast as the number of EVs.

 

[gavine]

insulate the entire garage, which includes all of the walls, the roof, and of course, the garage door.

Insulated garage doors make a HUGE difference. My entire garage is fully insulated but not the doors originally. When I replaced the doors with insulated ones, the difference was very noticeable.

 

[Favguy]

Ok, So I've been using my Long Range to drive about 40 to 50 miles every other day. My usual habit is to charge to 70% and run it for two or three sessions by which time it's down to about 30%, then I charge it back to 70%. All home charging at 5.75kW.

I'm sure the above isn't too stressful for it, but would I it be even better if I started charging back to 55% after each use?

 

[STS-134]

Ok, So I've been using my Long Range to drive about 40 to 50 miles every other day. My usual habit is to charge to 70% and run it for two or three sessions by which time it's down to about 30%, then I charge it back to 70%. All home charging at 5.75kW.

I'm sure the above isn't too stressful for it, but would I it be even better if I started charging back to 55% after each use?

For 40-50 miles every other day? Charge to 50% after each use. 50% SoC on the S LR should cover at least 175-200 miles, which is way more than you need.