Tesla Model S Battery Life Study Charted By Plug In America

2 years ago by Mark Kane 87

Model S Reported Battery Capacity vs Miles Driven (source: Plug In America)

Model S Reported Battery Capacity vs Miles Driven (source: Plug In America)

Tesla Model S and Panasonic lithium-ion battery cell

Tesla Model S and Panasonic lithium-ion battery cell

Plug In America’s on-going battery study about the battery capacity of Tesla Model S sedans over time reveals the trends in capacity drop with increasing mileage.

The data (mostly from 85 and 60 kWh versions of the S in RWD configuration) comes from Tesla Model S Survey Form, similar to the Tesla Roadster study.

According to the graph, capacity drop for Model S 85 kWh should be just below 10% on average after 100,000 miles.

The plan for the future is to collect more data on the 70 and 90 kWh versions, as well as for the Model X 90 kWh.

An interesting finding also comes from the replacement rates for major components – both drive unit and battery swaps seem to be decreasing over time to 2.2% (each):

Major Maintenance Rates (source: Plug In America)

Major Maintenance Rates (source: Plug In America)

The median odometer values give a rough idea of how many miles the vehicles in each group have been driven. Half of the vehicles in each year reported fewer miles than the median and half reported more as of when last updated.

Year Vehicles Median Odo
Miles
Drive Unit
Swap %
Battery
Swap %
Charger
Swap %
2012 106 29,284 37.7 16.0 9.4
2013 253 22,525 28.9 5.5 4.3
2014 67 17,500 20.9 1.5 6.0
2015 45 7,542 2.2 2.2 0.0
2016 8 813 0.0 0.0 0.0
479

source: Teslarati.com

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87 responses to "Tesla Model S Battery Life Study Charted By Plug In America"

  1. Four Electrics says:

    The replacement rates for major components are broken down by model year, not replacement year. This makes them much less useful. Older cars always need more maintenance than newer ones.

    1. Mr. M says:

      No car that is driven below 100.000 miles / 4 years should have a drive unit replacement. Being 20% above is really bad. Since a normal ICE is good for up to 300.000 miles a electric drive unit should be build to last at least the same time.

      1. Anon says:

        Average ICE lifespan is about 150,000 – 200,000 miles. Stop exaggerating.

        https://en.wikipedia.org/wiki/Car_longevity

        The latest Tesla drive units were re-designed to last for One Million Miles, BTW.

        1. sven says:

          Your link shows ICE vehicle life, not ICE engine life. Cars could reach the end of their useful life with an ICE engine in perfect working order. In the Northeast, many cars get junked because they rust out.

          1. Anon says:

            No engine, no vehicle life. Pretty simple.

            1. Dan says:

              Read sven’s comment again. The engine in an ICE outlasts the car, not the other way around.

              1. Nick says:

                So claimed, any evidence?
                Many engine failures junk a car with 75k+ miles due to low residual value. Often doesn’t make sense to repair at that point.

                1. Mxs says:

                  Where is your evidence?? I will help you, it doesn’t exist so it’s easy to make stuff up. It’s simple you don’t understand engines, don’t comment on it. It’s better tat way for everyone.

          2. Terawatt says:

            Oh really? That would be… pretty stupid.

            Look, nobody takes a brand new car and fits it with an engine from a scrapper. So even if this were true, it wouldn’t be relevant.

            And industry has been careful not to over-engineer ever since the early days of mass production.

            Haven’t you read the famous story about the Ford Model T kingpin? Some years after Model T production began, when they started being scrapped, Ford sent his chief engineers to a scrapyard to examine the various parts’ conditions. They came back and said it was bad news. Nearly all the parts were quite worn and no longer in good condition. But the kingpin was an exception – they were all quite pristine. Ford immediately ordered that the kingpin should be shrunk. Using extra material to make a component outlast the vehicle did nothing but add cost and weight.

            By the same token, people used to say that the ideal race car crosses the finish line in first position – and then breaks down immediately. The idea being that if the car’s life exceeds the race distance you could have used less material and saved weight. (In modern F1 there are limits on how many engines one can use in a season and the like, to keep costs down, but before these rules F1 teams used one engine for qualifying and a new one the next day for the race!)

            1. sven says:

              What would be pretty stupid? Nobody suggested or said anything about putting an ICE engine from a scrapper into a brand new car.

            2. Brave Lil' Toaster says:

              Your “ideal race car” isn’t so much an engineering challenge, but it means more that the driver extracted the maximum amount of wear from the drivetrain, without breaking it. Just under that, she wasn’t driving it hard enough, just over that, and she doesn’t finish.

          3. arne-nl says:

            Don’t forget the gearbox, a failure-prone and expensive to repair drivetrain component. We’re not talking engine/motor failures, but drive train failures, which in the case of an ICE should include the engine, exhaust system, cooling system, gearbox, clutch.

            1. Mint says:

              Excellent point.

              Moreover, the replacements were usually done when there was simply abnormal noise, not a failure.

              Applying that standard to full ICE drivetrains would yield many times higher failure rate than just looking at engine death.

        2. telveer says:

          Modern gasoline engines from good automakers generally outlast the lifetime of the car. I sold my old sedan after 275K miles out of sheer boredom. The engine was still silky smooth and efficient. I did not even get the timing belt changed! Just regular oil changes every 10K miles or so. Given how complicated the engines are, I was very surprised that they lasted that long. Electric motors should last indefinitely too. Tesla definitely had a major issue with their motors. We give them a pass because they are the cool new kid on the block.

      2. Rob Stark says:

        A Honda or Toyota ICE with perfect maintenance will last 300k plus miles.

        Honda or Toyota Auto Transmission not so much. Refurbishment is a major expense.

        Everyone else not so much.

        There are always outliers and liars.

        1. Anon says:

          So, two brands and perfect maintenance– and you might get 300K.

          What percentage of global ice ownership does that actually represent?

          1. Mxs says:

            Most of your ICE comments are just down right silly. You think you are somehow helping the electrification movement this way?

      3. manbitesgas says:

        Sure, but what is the total cost of maintenance and replacement parts for ICE over 300K miles? I mean, as long as we’re comparing apples to apples, how about performing the same amount of maintenance on an ICE as you do on a Tesla drive unit (none, zero, zilch) and then see how long they last… People always forget to price-in the externalities…

        1. sven says:

          manbitesgas said:
          “People always forget to price-in the externalities…”

          I think you’re guilty of that yourself. A Tesla driven 10,000 miles per year for 16 years (160,000 miles total), you would pay the following for Tesla maintenance service:

          Years 1-4: $400 + $700 + $400 + $900 = $2,400
          Years 5-8: $400 + $700 + $400 + $900 = $2,400
          Years 9-12: $400 + $700 + $400 + $900 = $2,400
          Years 13-16: $400 + $700 + $400 $900 = $2,400

          Tesla maintenance Years 1-15: $2,400 + $2,400 + $2,400 + $2,400 = $9,600

          https://www.teslamotors.com/support/service-plans

          1. Illuminati says:

            Tesla maintenance service are optional with no effect on warranty.

      4. JakeY says:

        A lot of drive units were replaced for noise and Tesla did not have a field repair process for their drive unit for the first few years (so drive unit was replaced and repaired at factory instead). They did this because it is so easy to take out the drive unit (unlike an ICE).

        The analogy with an ICE simply is not the same.

        1. Joshua Burstyn says:

          Yep. I tend to agree with you. Furthermore we had such excellent service that I can’t say we were very much inconvenienced, ever. I’m glad to see Tesla may have resolved many of the issues. They do make excellent cars but I also want them to get more reliable so that there are no unnecessary barriers to EV adoption. Please Tesla, continue to take this seriously and keep up the good fight.

      5. Pushmi-Pullyu says:

        Mr. M said:

        “…a normal ICE is good for up to 300.000 miles…”

        Maybe that’s true in some petrol-sniffer fantasy world, where “clean diesel” cars actually exist.

        But not on Planet Earth.

        1. Chris says:

          300000 is about the minimum for me if I don’t think I can get 300,000 miles out of a car I won’t even consider it except for my EV simply because it saves me so much money I have no doubt the car drivetrain will last 300000 but obviously the battery will not

          My 88 Jeep Cherokee had 497 thousand miles on it when I sold it and it still ran I drove to the guy’s house who bought it from me needless to say he was shocked. that inline 6 engine is damn near indestructible and I put almost no maintenance into it never cracked the seal on that engine.

          I put over 250,000 miles on multiple minivans voyager’s no engine troubles rust killed both of them

          We have had multiple for cargo vans with over 300,000 miles one of them over 400,000 miles again something besides the engine killed them each time

          My Geo Metro currently has 280000 miles on it still runs like a top it will continue to do so as long as I can keep the the rust from eating the car.

          I give test lab pass because the car is brand new they need to work out bugs and problems so long as they back their product I don’t see a problem once those problems are worked out the drivetrain on an electric car should go a million miles no problem if it doesn’t there’s something wrong with it at a design level or it was abused or you just have bad luck it happens

          The big issue is battery capacity we need 450 miles range because what I want is 300 miles range to get 300 miles range I need for 450 miles range why? Degradation and weather my Nissan Leaf gets 75 miles in the summer but only 60 in the winter 40 if I use the heater

          What I want is a 300-mile range on the highway in the dead of winter with the heat on after I put 200,000 miles on the car that means I need to start with 450 in order to end up at 300 with those conditions although I would be totally happy with a 200 mile range Tesla the 450 it’s just the ideal that we need to strive for

          Although I should add I am an extreme case as I put 40 to 45 thousand miles a year on my cars

          I even drive the crap out of my limited range leaf 18 months 40000 miles in a Nissan Leaf damn the Range is short but I sure love this car I would rather die than by a bolt I’ll wait for a used Tesla

          1. Reddy says:

            Wow, I did a quick estimate from your numbers above and at 45,000 mi/yr you’d need nearly 65 yr of driving to put up those numbers, maybe even more. Since, you’re must now be at least 80 yo, I’d say your last statement maybe correct.

      6. jerryd says:

        Mr M,
        Most had only minor noise problem and replaced so they could check it out at the factory both to learn and cutting consumer
        downtime.
        Next Tesla doesn’t use Panasonic cells. They use Tesla cells made to Tesla patents and specs by Panasonic or other company or even by Tesla if needed.
        Panasonic is only a job shop.

        1. sven says:

          The cell chemistry belongs to Panasonic.

          1. Joshua Burstyn says:

            I believe Tesla cells are unique in that the organic solvents (possibly more) are unique. Panasonic may create the base cell design but Tesla definitely alters it for their use case.

    2. sven says:

      Yeah, the article says the following: “both drive unit and battery swaps seem to be decreasing over time to 2.2% (each).” Isn’t that to be expected, since the median mileage of those model year 2015 Teslas is only 7,542 miles. Those cars are practically brand new; they don’t have enough miles on them to fail just yet.

      Like Four Electrics said, the older Teslas with proportionately more miles on then had more motor, battery, and charger swaps.

      The chart also gives no information on whether a car that received multiple motor swaps or engine swaps had those swaps counted or was it limited for reporting purposes to one swap per car.

      1. Anon says:

        Keep in mind that the drivetrain replacements were typically not motor failures, but simply replaced due to noise.

        In a nearly silent EV, there is no explosive engine drone to mask other sounds as the vehicle ages.

        1. TomArt says:

          Exactly – it wasn’t like all these people were stranded due to a breakdown, or anything like that. A vast majority would have been preventive swaps.

          1. Joshua Burstyn says:

            Agreed. I have heard of extremely few vehicles which were inoperable and the standard refrain from the svc departments has been to replace the entire unit rather than troubleshoot or repair any of the three major components. (Inverter, reduction gearing, motor.)

  2. Barry says:

    I would like to see the battery depletion rate comparing cars that were charged primarily by Level 1, 2 and 3 chargers.

    1. Texas FFE says:

      There was a comparison presented on EVTV where one Leaf charged only with L2 was compared to another Leaf charged only with CHAdeMO. The test ran for 56,000 miles with both cars being charged three times a day. After the miles were complete the batteries of both cars we’re pulled from the cars and bench tested.

      Although there were differences in the remaining capacities of the batteries, the differences were marginal at best. The conclusion of the test was that concerns that higher charging rates would significantly degrade battery capacity over time are unfounded.

      1. Phil Trubey says:

        Yes, fears over battery degradation when charging at Superchargers rates is persistent even though there isnt a shred of evidence that it occurs.

        1. przemo_li says:

          Evidence is in plenty abundance.

          Car auto makers are experts in it! And thus they avoid most damaging ways in which You can destroy battery while charging.

          Electronics monitor temperature, voltage, battery capacity and modify params so that charging is both safe to car and battery and human being handling the cable.

      2. Terawatt says:

        No conclusion should be drawn from such a test. Sample size 1 means that random variables play a big role.

        It’s like comparing one smoker to one non-smoker and draw conclusions based on how long they live. Given the huge variation in the life span of smokers and non-smokers alike, there’s something like (I’m guessing here) a 20% chance of concluding smoking makes you live longer, 30% chance of concluding smoking has no significant effect on human life span, and 50% chance of concluding smoking shortens your life.

        A study like this is still interesting. It shows that fast charging doesn’t NECESSARILY always ruin batteries. And it represents a small piece of evidence indicating that there’s only a very slight difference. But it’s nothing more than an indication.

  3. Nix says:

    This shows that aside from warranty replacements, that most battery packs should outlast the median useful life of typical ICE vehicles.

    1. sven says:

      How much of a factor is battery aging with regards to capacity loss? (i.e.: a battery in a car driven 100,000 miles in 3 years vs. 100,000 in 10 years)

      1. Dave says:

        I think… nobody knows the answer to that question yet. Time will tell… the oldest cars are nearly 4yrs old now.
        My car is 2.5yrs old and has 61,000 miles on it. Never had a breakdown. No brake pads needed until 450,000 miles, the way they are tracking. It shows about 257 miles of range now, versus 269 when I got it. (i.e. 96%)

      2. Nix says:

        sven, if you look at the raw data, range loss is more tightly tied to miles than years. Low miles trend to higher ranges regardless of what year the vehicle is.

        Age alone isn’t showing anywhere near the downwards trend as miles show.

        So no, age isn’t playing out to be a major factor.

      3. Pushmi-Pullyu says:

        sven asked:

        “How much of a factor is battery aging with regards to capacity loss? (i.e.: a battery in a car driven 100,000 miles in 3 years vs. 100,000 in 10 years)”

        I don’t think any production EV, with the possible exception of some older Leafs, is yet showing signs of battery capacity loss due to calendar age or “shelf life”. Look at the line on that graph; it’s pretty flat.

        I’m no expert on the subject, but from what I’ve read, once a battery starts losing capacity due to shelf life, the deterioration is pretty rapid. It’s not at all the same gentle decline you get from normal daily cycling.

  4. Jason says:

    Could this be accurate? Does a drive unit swap mean a new motor? 37%of all those cars needs a new motor? That goes contrary to the expectation that EV’s are more reliable than ICE’s. Most ICE get a new engine at >100,000 probably more like 250,000 if at all, not after a few years and medium range of 30,000mls.

    1. Texas FFE says:

      The drive unit failures are a known issue for Tesla and is probably why Consumer Reports drop their reliability rating of Tesla. I don’t know of any other BEV that is having drive unit reliability issues. ICE vehicles have a lot of these kinds of issues, I had a 2004 GMC Sonoma that burnt up two crankshafts and five starters before the extended warranty expired.

      1. Anthony Castro says:

        I had my 2011 Nissan Leaf up till 80,000 miles and the motor was still running with excellence

    2. Sergio says:

      The motor replacements are very misleading and truly nothing like replacing an engine on an ICE vehicle. These motors did not give out. They had one part that had been put together poorly and eventually started making noise. Tesla could’ve kept the cars for a few days to adjust the same motor but instead opted to quickly swap them out for the sake of convenience to their customers.

      1. sven says:

        So the motors are not easy to service? Why would it take three days to repair it at the service center?

        1. Will Davis says:

          They’re not easy to service.

        2. JakeY says:

          It probably won’t take 3 days of actual work (as in a mechanic working full time on that one unit), but certainly longer than it takes to swap the unit. I remember hearing it takes only 2 hours to swap the unit, so even a loaner might not be necessary.

          An ICE swap however is typically on the order of 15 hours (in customer time, might take a week as that work is spread out; a mechanic typically won’t be working exclusively on your car).

          Actually later on, after Tesla started field repairs, they just had the shop add a shim to the existing unit and new motor mounts instead of swapping. However, the default procedure before that was swapping the unit no matter what, because it was quick and easy to do so (then it was refurbed in the factory).

          1. Terawatt says:

            A mechanic won’t be working on one car at a time? That sounds very strange. Why would they design extra delay into the system??? A mechanic wouldn’t increase his throughout by going back and forth between different jobs, so all that would be achieved by organizing the work in this way is that each customer had to wait much longer.

            I think the overhead isn’t quite as bad as that. They surely have you bring your car a bit before they expect to start working on it, and pick it up a bit after they expect it to be ready. Having some slack is necessary since you can’t predict exactly how long each job will take.

            Only if you routinely discover during jobs that you are lacking required parts (or tooling) would it make sense to plan to service multiple cars in parallel. And even then it would only make sense to switch from one job to another when you actually have to wait for the part.

            1. JakeY says:

              Maybe “mechanic” isn’t the right word, but “shop” instead.

              Just browsing from the internet, a 15 hour billable job should take just 2 days. When you get a shop that works exclusively on your car, that’s what it takes (and it seems smaller shops are like this).

              However, it seems dealerships typically take on the order of a week. It may be parts as you mention, but I suspect mechanics can get pulled off to do smaller quick jobs rather than just working on one car.

        3. Pushmi-Pullyu says:

          I don’t know if it’s still true, but in the past the normal procedure for a Model S drive unit replacement & repair was for the service center to swap out the existing unit with a refurbished unit, and then ship the unit that was removed back to the Fremont factory for teardown, diagnosis, and refurbishment. That was a faster way to get the customer’s car back in tip-top condition, and at least according to what’s been reported, the service shops were not equipped to handle a proper teardown and diagnosis of the drive unit.

          It seems strange that if all the car needed was an adjustment to, or replacement of, the fixed gear ration gearbox, that they would remove the entire drive unit and ship it back to Fremont. But apparently it was less expensive for Tesla to do it that way.

          Whether or not that’s still the procedure they’re using, I don’t know.

          1. arne-nl says:

            Actually, when I think of it, it is a smart way doing it like that.

            A drive unit is a delicate, highly stressed component and you want it put together in just the right way. Clean workplace, right amount of oil, everything aligned and adjusted and tightened precisely according to specs.

            I remember a story of a guy that bought a Prius with a broken power split device. At disassembling the unit, he discovered that the problem was a hose that had been incorrectly fitted, and there was a tiny gap where water and dirt could enter the unit. It was doomed the day it exited the Toyota factory.

            Also, by concentrating the work you get a specialised team that can do it better and cheaper. Win/win/win. You get better repairs, Tesla is cheaper off and the customer is quickly back on the road.

        4. jerryd says:

          Sven,
          They are easy to service as a complete rebuild takes less than 30 minutes.
          In new products like this shipping back to the factory let’s them figure out what went wrong is a smart thing.

    3. Dave says:

      Tesla elected to replace most of the drive units concerned. The owners didn’t suffer breakdowns or other problems. (in the vast majority of cases)

    4. Pushmi-Pullyu says:

      Jason asked:

      “Could this be accurate? Does a drive unit swap mean a new motor? 37%of all those cars needs a new motor?”

      If they got a drive unit swap, then they replaced the motor, along with the inverter and the reduction gearbox. That’s all contained in one unit, so it’s easier and faster for the Tesla service departments to swap out the whole thing.

      However, it’s an open question whether or not most of those cars actually needed a new motor. When a Model S is taken in for a quarterly checkup, the service people do a very thorough checkup. That includes listening to the sound of the motor at various speed and under various loads. If the service guy hears even an minor noise, the drive unit is replaced, even if the customer didn’t notice anything.

      And the replacement drive unit is probably a factory refurbished unit, not a new unit. So the answer to your question “Does a drive swap mean a new motor?”, technically the answer is “No”… it’s a different motor, but not actually new.

      Note the most common reason for swapping out the drive unit is a “milling noise” that apparently comes from the reduction gear, not the motor. So probably most of those motor replacements aren’t needed at all. Since Tesla never lets units making noise continue to run until they fail, we don’t have data on how often (or seldom) that potential problem would turn into a real one.

      As JakeY suggested or said above, replacing a Model S drive unit is much more simple and easy than replacing a gasmobile’s engine. It sounds like it’s equivalent, but really it’s not.

  5. SJC says:

    I expect Model S packs to do well, that does not mean they have the same range after 100,000 miles. So if you can handle 160 miles when you used to have 200, live with it.

  6. Could you normalize the maintenance chart with respect to mileage?

  7. Samwise says:

    One interesting thing is the degredation lines are basically parallel regardless of capacity.
    A 300 mile battery looks to lose a similar number of miles as a 200 mile battery over a certain number of miles driven, at the extreme end this would mean that when a 200 mile battery reaches 1/2 it’s original capacity a 300 mile unit would have only dropped to 2/3 its original capacity (they both would have lost 100 miles).

    1. HVACman says:

      The higher the kWh rating of the battery, the less deep it typically goes into its storage discharge on a daily drive cycle. Battery cycle life is somewhat sensitive to the average depth of discharge in each daily cycle. If the rated range is 300 miles and it drives 40 miles/day, that is only 13% depth of discharge. For a 200-mile battery driving the same 40-mile daily drive cycle, it is 20% depth, which would shorten the life a little more.

      1. Carcus says:

        I guess it differently, and that the problem is on the upper end.

        The 200 mile cars are more likely to be “topped off” on a regular basis.

        1. Bonaire says:

          An assumption is that a generic 70 owner might range charge more often than a 90 owner. Meaning, they may do more damage to the cells by pushing the SOC up into an area that causes more degradation.

    2. Terawatt says:

      I see a couple of replies speculating this is because the smaller cap battery is more often at a very low or very high state of charge. Both are plausible explanations.

      However, I think there’s a simpler and more likely explanation. The chart relates capacity to miles, not time, and so it’s basically the same as capacity vs “total energy cycled through the battery”. For the larger battery this is fewer cycles (one cycle isn’t one charging session, but putting in and taking out one time the capacity of the battery).

      Total consumed energy is proportional to the mileage and number of charge cycles is inversely proportional to the capacity of the pack. So you’d expect to see parallel lines for packs of the same chemistry when charted against mileage.

      I think the top/bottom point is valid, but probably more relevant for cars that are routinely coming up against their range limit. I reckon a 200-mile EV for most people won’t often need to be charged to more than 80% or discharged below 20%.

      In practice this means you lose as much range as quickly (given the same driving) whether you use a small or large pack. It’s obviously more problematic to lose 25 miles if you started with 80 than if you started with 215 😉 so this is another reason it’s important to lift the “baseline” range above 200 miles.

      1. carcus says:

        “….. you lose as much range as quickly (given the same driving) whether you use a small or large pack.”

        But this does not appear to bear out in the graph. It’s kind of tough to see (as the lines are covered up by the individual data points) but if you look close you can see the smaller the pack — the steeper the decline in battery capacity (in miles) vs miles driven.

  8. HVACman says:

    Two questions:

    1. Is there any battery efficiency loss as it degrades – does it take as many kWh to charge as new, but only return the degraded kWh range, or does it also take less kWh to charge?

    2. are there published statistics anywhere what a typical compression loss is in a current-generation, properly-maintained ICE engine over its life, in % per 100,000 miles?

    1. 1) Virtually any battery that is degrading is increasing its internal resistance, therefore the amount of energy pulled from the grid will increase while the amount of energy available for autonomous power will decrease.

      To answer your question better even though the internal resistance increases the degradation is likely more relevant to the overall equation. So while the energy requirement may go up 5% because of internal resistance, the stored capacity may go down 10%. Overall energy consumption with the degraded battery may be less. Charging efficiency will most definitely be lower.

      2) My last car that was gasoline powered had 140,000 miles from new. It’s original gas mileage was around 18 and when I sold it was around 15 or 16, so all things considered, efficiency went down. Obviously just an anecdote but I believe to be representative.

  9. My Model S 70 D has 32,000 miles. It fully charged to 229 rated miles out of 240 rated miles, so about 4.5% degradation, assuming that Tesla plays no funny business with rated range.

    1. Jonathan says:

      You do realize that this is an estimate of how much range you have left? A lot of this is based on your driving habits as well. My guess is that based on the way you drive, your Model S is starting to predict your range with more accuracy. You’re unlikely to have much degradation at all at 33K miles.

      1. Mike I says:

        Unlike other EVs, Tesla’s Rated Range is only an indication of the usable energy, NOT your driving habits. The “Funny Business” Tony is talking about is the Wh/mi constant that Tesla applies depending on the car model. There could also be some change to the available energy calculation from one firmware rev to the next.

        1. Joshua Burstyn says:

          There have definitely been ajustments to the calculation over time. When we received our car it routinely read 383kms range. Between one rev. of the firmware and the next we dropped 10kms with no change to the SoC. Small change but until we had the pack verified and leveled the pack we were a bit worried.

    2. jimstack007 says:

      my 2013 FORD Focus EV 3 HOT summers in PHX and 25K miles shows 115 mile rate when it was rated for 76. So that’s a gain of about 50%. I drive like I care.
      I rate it by battery capacity shown on the OBDII port with a SCAN GAUGE made just for FORDS. It has lost 0% Battery capacity.

  10. Get Real says:

    Another nail in the coffins of the haters like the so-called professor (who not-so-coincidentally was a writer for the Murdoch-owned WSJ for 13 years prior) who seeks to spread ridiculous FUD in this IEVs article:

    http://insideevs.com/radically-better-batteries-unlikely-anytime-soon/

    The drive train replacements, while not a good thing obviously, are to often dramatically overstated as if they were units that are completely ruined/worn out. When in fact they have one part that wore to the point of becoming noisy and the units are swapped for other units that they have fixed.

    In any case these issued are more likely to arise for Tesla as new company as long as they learn from this and eliminate it on newer models and satisfactorily repair the problems for the owners affected.

  11. georges says:

    10% in 10 years seems reasonable. The next 5-10 will be even more interesting. We don’t see shelf life influencing things yet.

  12. wdolson says:

    The comparison of a drive unit swap to an ICE engine change is a bit of comparing apples to oranges. Internal combustion engines are very complex mechanisms with many, many interconnects. Pulling the engine is usually the absolute last resort after all other options have been exhausted. When an ICE comes in for service on the engine, the goal is to do everything possible to keep the engine in the car.

    With an electric motor, especially the DU on a car like a Tesla, changing the drive unit is about as difficult as changing the oil on an ICE. There are many scenarios like the motor making unusual noises, but still operational where the engine would stay in an ICE and the dealer would try and fix the problem doing other things where it’s just quicker and simpler for the Tesla service center to pull the DU and send the unit back to a remanufacturing center to be repaired.

    In the early days Tesla was trying to figure out why drive units were having problems and pulled units that were not behaving right so their engineers could determine what was wrong.

    There have been very few cases where a drive unit actually failed on a Tesla. By failed I mean stopped by the side of the road waiting for a tow truck because the car isn’t drivable. That’s very different from an odd noise, or a minor fluid leak.

    My ICE started leaking a little oil before it was out of warranty, but the dealer wasn’t able to fix it and it wasn’t fixed. It’s been 24 years with a minor oil leak and the car keeps running fine. If the same sort of problem had occurred on a Tesla, Tesla probably would have replaced the drive unit.

    1. TomArt says:

      Good point.

  13. Jonathan says:

    Comparing this to my 2015 Nissan Leaf, which has lost about 6% capacity in 30K miles of use (and this is low compared to others) I’m pretty happy with the relatively mild degradation on the Tesla batteries.

    When my Model 3 is ready, I will definitely be purchasing the larger battery (assuming its no more than a $6K uncharge). Here’s how I look at it. The battery size increase will mean that it will cycle less frequently and last slightly longer than a smaller pack. So while a 60kwh pack may lose 10% over 100K miles, a 75kwh pack may only lose 8%. Scale this out to 200k miles and your 215mi range model 3 will be down to 160 miles of range while a 280mi range model 3 will be down to 238 miles. Meaning that your larger pack will yield you more range after 200K miles than the smaller pack did when new. Also that smaller pack after degradation will push the limits of the supercharger network distance for long range travel.

    1. sveno says:

      Same here. It would not be an issue (having a smaller battery) if I knew that I could replace it with a larger one down the road.

      But what I would really like is some battery manufacturer to start making aftermarket Leaf batteries, esp when Leaf 2 comes out and there is virtually zero chance that Nissan will be working on battery upgrades for gen 1 after that.

      Leaf ownership seems more risky than Tesla as you know that Tesla will support the model as long as they possibly can with software and hardware upgrades.
      That’s why I have purchased Apple phones – they always have 4-5 years of meaningful software updates.

    2. Bonaire says:

      LG Chem did well with the Volt design. Many of us with 2011 cars still get more than 40-45 miles on a charge for a car that was rates for 35 miles of range.

  14. Pushmi-Pullyu says:

    From the article:

    “According to the graph, capacity drop for Model S 85 kWh should be just below 10% on average after 100,000 miles.”

    Nice to see a longer-term study confirms what was suggested by a tentative earlier study that had a rather small sample size. As I recall, the earlier one was also from Plug-in America.

    “…both drive unit and battery swaps seem to be decreasing over time to 2.2% (each)”

    Still seems to be higher than it ought to be, to me. But it’s great to finally have a real number to cite, to refute the overwhelming number of Tesla basher claims that 16% or 35% or “nearly all” Model S’s have had the drive unit and/or battery pack replaced.

    I’ll bookmark this study for future reference… since I’m sure we’ll see those Tesla basher claims again, and again, and again. They’ve developed a real talent for ignoring actual facts. >:-/

    1. Pushmi-Pullyu says:

      Oops! Posted too soon re the drive unit & battery pack swaps. Looks like the “approaching 2.2%” applies only to fairly newcars. The data from Plug-in America shows much higher percentages Model S’s a few years old.

      Maybe some of the less rabid Tesla bashers were right about those percentages. 🙁

  15. Giovanni says:

    “Half of the vehicles in each year reported fewer miles than the median and half reported more as of when last updated.”
    Isn’t that the definition of median?

  16. Nero says:

    Find Bjorn Nyland on YouTube, he checked his Model S for degradation and it was just few percents and he is doing a lot of miles. Last time I’ve seen it had 220.000 km on his clock.

    1. Mikael says:

      He has had a battery swap after the original pack broke down.

  17. SparkEV says:

    It’s interesting the trend is linear with Tesla. I had expected exponential. Kevin from SparkEV forum kept a log of his 2014 SparkEV battery degradation (A123 battery), and he came up with polynomial fit.

    I wonder if Tesla would also be different (not linear) if one car is taken and measured vs many different cars like in the article.

  18. Alex says:

    That are many issues with battery and drive unit. Hopefully they get Model 3 not to early, it would be a huge loss for them changing 200.000 drive units some years later.

  19. ModernMarvelFan says:

    Well, it shouldn’t be a big degradation with usage.

    100K miles with Tesla’s large battery, it is only about 500 cycles, that is pretty much nothing on a battery that is easily rated for 2,000 cycles.

    However, as the battery pack ages, the 2nd factor (aging) will start to creep in as secondary reason for degradation.

    But either way, I expect easily 200K miles out of the Tesla battery.

    1. Bonaire says:

      Don’t be so sure 2000 recharges will be the target. The interesting thing with chart is just how few miles are driven by these cars in general. Let’s see how things look in two more years.