Historical worst case battery degradation

[Hairdryer]

Hello all.

I am the happy owner of a new 100D Long Range. The car is gorgeous.

I don't have charging available at home (looking in to renting a place with a drive or garage that would make this feasible, but that would be a way off).

I'm interested to know what the absolute worst case is WRT only using superchargers to charge the car, car left unplugged overnight, etc.

Let's say we generally stick between 40 and 80% SoC, car left idle in that range, occasionally dropping to 10-20% on longer journeys as necessary.

The best example I've seen is Tesloop's vehicle which seems to essentially have been used in such a way (but maybe it was plugged in overnight).

Thoughts? Can I expect to see e.g. 10% degradation over 100K miles?

 

[iqless]

10% degradation over 100k miles for doing the exact opposite of what Tesla tells us to do wouldn't be so bad.

That being said, I had a 85D which was exclusively supercharged & never plugged in, and over my 20,000 miles / 2 years of driving the car I think I lost a total of 1 mile.

 

[ucmndd]

It’s a little bit luck of the draw, although in general the 100kwh batteries have proven to be quite robust.

On the other hand my 75kwh battery at 80k miles has lost 11% of its original rated range despite treating it basically as Tesla recommends with daily L2 charging, 90% limit excluding a couple dozen 100% trip charges, and occasional supercharging.

 

[Hairdryer]

I guess what I'm looking for is the worst case?
Are there any reports of anyone losing e.g. 25% over 100K miles?
(Paradoxically it seems as if a full battery failure would be preferable as then it's definitely a warranty issue)

 

[iqless]

That 75 of yours definitely fared much worse than average. How many miles are on it?

 

[ucmndd]

I guess what I'm looking for is the worst case?
Are there any reports of anyone losing e.g. 25% over 100K miles?

There are a handful of very early 2012-2013 60kwh cars that have seen some pretty severe degradation, approaching that 25% figure.

That’s definitely the exception though, I don’t believe there are any examples of more recent models anywhere close to that. As I said, the 100kwh battery has proven thus far to be among the best.

 

[Hairdryer]

Cheers. I appreciate the input. Sounds like providing I get major issues sorted during the 50K mile warranty (I expect to blow through this in under four year) I should be good.

 

[jmaddr]

Don’t forget I think the warranty is 8y or 125k. I don’t think the X specifies a level, but for the three it’s 70%. That’s the worst case scenario.

 

[ucmndd]

Don’t forget I think the warranty is 8y or 125k.

The S/X battery warranty is 8 years *unlimited* miles, but does not include any replacement threshold for "normal" degradation like the 3.

 

[dmckinstry]

Hello all.

I am the happy owner of a new 100D Long Range. The car is gorgeous.

I don't have charging available at home (looking in to renting a place with a drive or garage that would make this feasible, but that would be a way off).

I'm interested to know what the absolute worst case is WRT only using superchargers to charge the car, car left unplugged overnight, etc.

Let's say we generally stick between 40 and 80% SoC, car left idle in that range, occasionally dropping to 10-20% on longer journeys as necessary.

The best example I've seen is Tesloop's vehicle which seems to essentially have been used in such a way (but maybe it was plugged in overnight).

Thoughts? Can I expect to see e.g. 10% degradation over 100K miles?

I doubt it. I have a degradation of 9.6% in 130k miles in 3 weeks less than 6 years. I normally charge to 90% at home on either a 30 A dryer plug or a Nema 14-50 ( at my previous house). On road trips in earlier days (when Superchargers were sparsely located) I would max range charge at 8 out 10 charges between Eastern Washington and Palm Springs, CA. I only rarely charge to only 80%. With a 100D charging to only 80% you should much better.

 

[DirtyT3sla]

I think the absolute worst thing for the battery is storage at extremes (0%/100%). Beyond that, the rest is probably just "not optimal." It's best to have the car plugged in as much as possible because then it can very aggressively and accurately control temperature without worrying about killing your range just sitting there.

I feel like it's hard to tell how the habits will effect the battery, because all the reading I've done there doesn't seem to be a strict pattern (e.g. guy 1 does exactly what tesla says, has bad degradation, guy 2 supercharges every day and doesn't plug in over night and degradation isn't that bad).

I made a video about my degradation on my TM3 AWD at 13,000 miles. I'm seeing 307 mile at 100% charge.

The video has some casual battery info you may not be interested in, so check the time stamps in the description. Also watch some of the scientific explanations linked in the description to form your own opinion

I guess the worst case scenario ever would be 29% degradation, because Tesla claims to replace the battery at 30% degradation under warranty (at least for the 3...on the website the wording is vague. It just says the S battery is under warranty for 8 years unlimited miles, but doesn't mention any sort of degradation cut off).

Even batteries from a few years ago seem to hold up extremely well after 100k miles, so I would assume you will have nothing to worry about.

And if something does go wrong, hopefully Tesla will have your back.

 

[ran349]

It’s a little bit luck of the draw, although in general the 100kwh batteries have proven to be quite robust.

On the other hand my 75kwh battery at 80k miles has lost 11% of its original rated range despite treating it basically as Tesla recommends with daily L2 charging, 90% limit excluding a couple dozen 100% trip charges, and occasional supercharging.

My case is similar to yours. At about 75k miles, I have 10% degradation. I charge to 80%, never supercharge, and my daily driving range is between 50-80%. I am not going out of my way to be careful with my battery, it's just a convenient routine for me.
My reward for this behavior will probably be a continuing degradation of my battery, but never enough of a failure to warrant a replacement.

 

[Snowstorm]

I have 5% degradation after 50k miles on a 100D model S. Almost all of that occurred within the first 30k miles. It has been steady since. L2 charge to 80-90%, 100% charged about 5 times, supercharged maybe 25 times.

 

[joltheadq]

My P85D only charges to 236 miles and SuC stops at 97%. I spent 2 hours today at Tesla service debating the TOTAL=72 kWh that was added to the car charging from 2-97% SOC on my screen is significantly decreased than when I purchased this car used @ ~60K miles. They said that they would consider a degradation down to 220 miles at 100% SOC would be grounds for battery replacement. I recorded the whole conversation on camera. I've only driven the car ~40K miles as the current milage is 91K. Mixture of L2 and SuC during that duration. According to ( Tesla’s hacked Battery Management System exposes the real usable capacity of its battery packs - Electrek ) the Model S 85 cars have a ~81.5 kWh total capacity, ~77.5 kWh usable. 72kWh/81.5kWh = 88% capacity compared to original. I say 81.5kWh because I no longer have any buffer after 0% SOC. I wasn't close enough to a SuC and had to get towed right at 0% SOC. No negative SOC buffer to act as a reserve for this Model S I own. SuC is very slow. as well. Pretty much stays at 60 kWh between 39% - 58% SOC and really slows down after that.

I'm pretty frustrated that I paid $60K for this car. It's like they look the other way when presented any concrete evidence of degradation. And recommend to just drive slower while eating your $60K loss of a car. What a hole in the wallet! I hate that I gambled on a used Tesla. The previous owner probably hot rod it because he had a professionally installed k40 laser jammer radar detecer in the vehicle. There is really no way of knowing what you're getting when you buy a used EV. I'm against recommending that anyone buy used from Tesla if they don't acknowledge premature battery degradation.

 

[ucmndd]

I'm pretty frustrated that I paid $60K for this car. It's like they look the other way when presented any concrete evidence of degradation.

They don’t need to look the other way, as the battery warranty specifically does not cover degradation, which you presumably knew (or should have known) when you bought the car.

The battery buffer doesn’t exist so you can drive past zero. Zero is zero. The buffer is to prevent permanent damage to the battery, not so you can drive past zero miles.

As for the real math, your P85D had an EPA rated 242 miles at 100% when new. If you’re at 236 right now, that’s 2.5% degradation, which is phenomenal for a 100k mile EV.

The rest of your math is made up and/or misinformed.

 

[P85_DA]

As for the real math, your P85D had an EPA rated 242 miles at 100%

Original P85D range was 253 epa

 

[ucmndd]

Original P85D range was 253 epa

Thanks for the correction. The first hits back from google said 242, which I thought was weird, but...

So they’re at 7% degradation at 90k miles. Still perfectly normal.

 

[Snowstorm]

72kWh/81.5kWh = 88% capacity compared to original. I say 81.5kWh because I no longer have any buffer after 0% SOC

The buffer doesn’t work that way. The buffer isn’t there for emergency mobility use but there to prevent permanent battery damage. As such you cannot use it. It is there below 0% and your car car move. So you would have to subtract the buffer from 81.5k to get the actual ideal usable amount. If buffer is 4.5kw, then actually usable without degradation is around 77kw.

Your degradation at 236mi @100% isn’t bad at all. It only represent 6-7% or so degradation from 253mi new and you have 91k miles. Degradation usually happens quickly in the first 1-2 years and then stabilize. I lost 5% in the first 30k miles and then almost nothing since.

There are many variable for supercharger speed. It is actually slower at very low state of charge (like your picture) and then speeds up around 10-15%. It all assumes the battery is warmed up, and the station has full power that is not shared. Check a better route planner blog for the curves.

Nothing seems really wrong from your description.

 

[joltheadq]

I have read post on forum.tesla.com about 6% SoC degradation after 200k miles. I’m well on my way to more than 10% loss of SoC and I’m not at 100k miles yet. Are you telling me you see nothing wrong with that?

 

[animorph]

I have read post on forum.tesla.com about 6% SoC degradation after 200k miles. I’m well on my way to more than 10% loss of SoC and I’m not at 100k miles yet. Are you telling me you see nothing wrong with that?

The degradation is non-linear. Most Teslas around your vintage quickly lost 6% and then leveled off for a long while. There is a lot of variation between individual cars. So yes, 6% or 10% can be completely normal.

Here's an article to start:
https://electrek.co/2018/04/14/tesla-battery-degradation-data/