Impressed how the battery holds up after 73k miles

[David99]

I had my Model S (85 RWD) for just over 2 years now. I drove 73,500 miles so far. That's quite a lot for 2 years. One of the biggest concerns with EVs is obviously how well the battery holds up as it's the single most expensive part.

When I got it new I was promised 265 rated miles. For the first few weeks the 100% charge went even a little higher. Now after 2 years, many long road trips though burning hot deserts and freezing winter storms, several hundred Supercharger uses, my 100% charge is at 253 miles. I have to say I'm very impressed! That's better than I expected and very encouraging!

I added my data to the chart here
MaxRange Tesla Battery Survey

Looks like I'm a little above average which is of course great, but again, I didn't expect it living in a very warm climate which is known to accelerate battery degradation.

This google sheet is actually pretty interesting. There is a page sorting the data based on daily charge level and supercharger use. It seems to show that both Supercharger use and charging to 100% more often doesn't affect battery degradation much. At least the data doesn't show a trend.

I've also been able to monitor some data from the battery recently. It's stunning that the average difference between the modules is only 4-5 mV which means the difference is only 0.1%. Anyone familiar with battery packs knows this means the pack is kept extremely well balanced. The temperature between the modules is also very close. Usually only 2 degree F difference. Again, that's very impressive. Tesla really has it's BMS down!

 

[SmartElectric]

Nice! Our early 2013 S85 has 46000 miles and is in great shape just like yours, less than 4% degradation. Folks who fear the "A" pack shouldn't!

 

[Edmond]

How do you charge David?

 

[Jeff N]

This google sheet is actually pretty interesting. There is a page sorting the data based on daily charge level and supercharger use. It seems to show that both Supercharger use and charging to 100% more often doesn't affect battery degradation much. At least the data doesn't show a trend.

The "stats" tab seems to show that only 1 person out of 182 respondents said they charged their car to 100% on a daily basis. On a separate question, only 3 out of 219 responders said they did a 100% charge as often as twice a week while a commutative total of 7 said they do this as often as once a week.

The summary comment says:

According to the data, charging to 90% is the best option, closely followed by 80%. The other options have too few entries and should be ignored.

Another summary does say:

According to the data, charging to 100% frequently doesn't have any negative effect on battery life.

But, "frequently" seems mean charging to 100% no more often than once or twice a month. The 7 people who charged more often than that probably do not represent enough responses to be usefully representative.

 

[David99]

How do you charge David?

My timer starts charging at 2 am. Most of the time I charge to 80%. Most days I end with 30-40%. On longer days I charge to 90 and end at 20%. I have a single charger charging at 10 kW. I rarely charge on public stations during the day. On trips I use Superchargers of course. I estimate I used Superchargers about 200-300 times in the last two years. 40% of my miles are driven using Superchargers.

 

[David99]

But, "frequently" seems mean charging to 100% no more often than once or twice a month. The 7 people who charged more often than that probably do not represent enough responses to be usefully representative.

I hear you, there isn't enough data to make solid conclusions. It is a fact that batteries age faster when charged higher. We all know it. Just how much, we don't know.
We tend to think of how high we charge the battery, but what is probably much more important in terms of battery aging is what is the average state of charge. When I charge to 90% and then drive it down to 10%, the average state of charge over the entire time is 50%. I did an average of several months of data I collected from my car and the average state of charge was 63%. Again, I believe that number is more important than how high I charge just before I start driving.

 

[Todd Burch]

I'm at 98.5% after 35,000 miles on my Oct 2014 P85. (I still get 261 miles on a full charge, out of 265 when new). That seems to be right near the top of the observations. I charge almost every day to 90%, except occasionally one weekend day I don't charge at all. I usually drive down 15% to 75% in the morning, then after work another 15% down to 60% SOC where it sits until I charge the next morning. I Supercharge around once a month (maybe just slightly less than that).

 

[trils0n]

Little over 3 years and 53k miles and have a 260 mile 100% charge (just did my first 100% charge in 2 years about 5 days ago as part of a road trip). Less than 2% degradation from 265 when it was new. Lots of supercharging (weekly for the last year) and quite a few roadtrips. Very happy with battery performance.

 

[Dutchie]

I am not so much interested in how it is holding up due to usage but more on how it is holding up over time..

 

[David99]

I am not so much interested in how it is holding up due to usage but more on how it is holding up over time..

very well! A car the same age as mine but only 20k miles showed significantly less degradation compared to mine. Mine shows about 6%, the other car showed only 2%.

 

[David99]

Quick update. After 82k miles I'm still at 253 miles at 100%. It confirms that degradation slows down over time.

 

[2Pearls]

Hello. We bought our Tesla Model S 85 in April 2013. We now have almost 75k very happy miles on our Tesla and We charge it to 80% at home on a single charger about 90% of the time only using 100% charge when we are traveling to NC, Florida or New England and we are still getting 253 miles when charging to 100%. At 80% Charge we are at 230 miles. We are very satisfied with these rated miles.
I should also state that we cruise on the highway between 80-90 mph and notice that 253 miles, at full charge gets us about 200 actual miles of driving, sometimes worse in extremely cold 10-30 degree weather. We are still happy with these numbers.

I am not one to prefer stopping multiple times on long trips, as I have seen other people on this forum state as their preference to stretch very often, so, if I was offered a battery that gave me 400+ rated miles, that would be my preference and I would gladly pay extra for those extra driving miles. Happy Driving!

 

[FlatSix911]

I had my Model S (85 RWD) for just over 2 years now. I drove 73,500 miles so far. That's quite a lot for 2 years. One of the biggest concerns with EVs is obviously how well the battery holds up as it's the single most expensive part.

When I got it new I was promised 265 rated miles. For the first few weeks the 100% charge went even a little higher. Now after 2 years, many long road trips though burning hot deserts and freezing winter storms, several hundred Supercharger uses, my 100% charge is at 253 miles. I have to say I'm very impressed! That's better than I expected and very encouraging!

I added my data to the chart here
MaxRange Tesla Battery Survey

Looks like I'm a little above average which is of course great, but again, I didn't expect it living in a very warm climate which is known to accelerate battery degradation.
View attachment 175527

This google sheet is actually pretty interesting. There is a page sorting the data based on daily charge level and supercharger use. It seems to show that both Supercharger use and charging to 100% more often doesn't affect battery degradation much. At least the data doesn't show a trend.

I've also been able to monitor some data from the battery recently. It's stunning that the average difference between the modules is only 4-5 mV which means the difference is only 0.1%. Anyone familiar with battery packs knows this means the pack is kept extremely well balanced. The temperature between the modules is also very close. Usually only 2 degree F difference. Again, that's very impressive. Tesla really has it's BMS down!

Interesting data. How did your remaining range increase from 95% to 96%?

 

[Matias]

When my 85D was brand new ( year ago), max range with range mode was 407 km, then about 6 months ago after some update it jumped to 422 and has stayed in that ever since.

Because of that sudden artificial jump I don't completely trust to degradation data.

 

[David99]

Interesting data. How did your remaining range increase from 95% to 96%?

I think a few things happened. I entally ented some data when I had range mode off or on. I believe it tries to compensate for it. So that nuges it up/down a bit. Also not every time you do a 100% charge is the battery gage perfectly calibrated. As Tesla said in an email, the 'rate range' number can change a little and can be less accurate if you partially charge and discharge, so there is some room for error. Over time they improved their algorithm so that probably also changed the numbers a little over the years.

 

[David99]

When my 85D was brand new ( year ago), max range with range mode was 407 km, then about 6 months ago after some update it jumped to 422 and has stayed in that ever since.

Because of that sudden artificial jump I don't completely trust to degradation data.

I think there was an update that enabled 'torque sleep' that actually increased range on the dual motor cars. That could explain the jump.

 

[apacheguy]

Rated miles is fine and dandy. But how quickly does your car SpC? Can you please post a recent taper curve? Resistance growth tends to impact the charge rates more than capacity.

 

[SmartElectric]

Resistance growth tends to impact the charge rates more than capacity.

Our early 2013 has an "A" pack original battery that charges at 90kW at low SOC.
I've not seen any indications that taper happens earlier in the past year.
Working great!

 

[David99]

I have written down some numbers when my car was relatively new and compared them to a very recent Supercharging session. The speed has not dropped much. About 5 kW less on average compared to when it was new.

 

[ecarfan]

When I got it new I was promised 265 rated miles. For the first few weeks the 100% charge went even a little higher. Now after 2 years, many long road trips though burning hot deserts and freezing winter storms, several hundred Supercharger uses, my 100% charge is at 253 miles. I have to say I'm very impressed!

Your experience, and that of thousands of other long time Tesla owners, is an EV success story that does not get enough publicity. I wish the popular press would pick up on it. As shown by the data you posted, Tesla Model S battery packs show very little loss of capacity over the first 100K miles of use, less than 10%, and by that time the projection into the future shows that degradation will be minimal. I have about 46K miles on my S and my max range has gone from 265 when new to 255-258 currently, about a 3% drop.

Over the past nearly 3 years I have spoken to so many people who think that EV batteries "wear out" and have to be replaced when the car reaches anywhere from 50K to 150K miles. I tell them that is simply not true, the data shows that Tesla battery packs likely have a useful life of hundreds of thousands of miles, and they are shocked. Then I tell them that EV batteries are continually declining in cost and increasing in energy density and that in a decade it is very likely I will be able to replace my Model S 85 battery pack for less than $10K and the car will last for another decade because it's aluminum body will still be solid and they can barely wrap their mind around that idea.

That is not to say I will own my current Model S in a decade, I won't, but I believe someone will and they will have a great car. It just won't be able to drive them hands free to wherever they want to go. But the Tesla I own a decade from now definitely will!