Model 3 (Stealth) Performance - 5y ownership, service history + high battery degradation?

[P3dStealth]

It comes out to 72kwh. I'm at 51% charge right now though. Car just turned 4 years old. Is that good or bad?

 

[AAKEE]

It comes out to 72kwh. I'm at 51% charge right now though. Car just turned 4 years old. Is that good or bad?

That seems quite good, and about what is expected if the battery mostly is at or below 55-60%.

Calendar aging which causes most of the degradation comes from [Time x Temperature x State of Charge].

So the climate and the temperature the car stands in has a noticable impact.

If the battery is above 60% SOC most of the time and the average temperature is ~25C or so you can expect about 5-6% calendar aging loss the first year and 10-12% after four years (Calendar aging reduces with the square root of time).

We would expect a battery that is mostly at or below 55-60% to degrade from calendar aging about 3-4% the first year and 6-8% after four years so your numbers that include also cyclic aging seems spot on.
(The climate assumed ”average”)

 

[P3dStealth]

I wonder if people are eventually going to start paying attention to this calculation when purchasing used cars. There are people that only supercharge to 90% every day and you would want to pay less for a battery treated like that.

 

[nicksp]

I wonder if people are eventually going to start paying attention to this calculation when purchasing used cars. There are people that only supercharge to 90% every day and you would want to pay less for a battery treated like that.

Recently there was a massive study performed on some 12.5k cars that were mostly supercharged. The conclusion was there was no more or less degradation than those not being supercharged.
Are there any such studies that show thousands of cars being tested to show otherwise?

 

[P3dStealth]

Recently there was a massive study performed on some 12.5k cars that were mostly supercharged. The conclusion was there was no more or less degradation than those not being supercharged.
Are there any such studies that show thousands of cars being tested to show otherwise?

I read a few articles on that study from recurrent. The articles make it sound like supercharging is the same but I have some questions. I am learning a lot about batteries lately lol.

They are comparing these cars but how many cycles of charges and what maximum charge level?

We know charging to 90% degrades the battery a little faster alone. Surely supercharging to 90% everyday is worse than just parking in my garage at 50%

Then there is the question of failure rate. They talk about battery degradation but not failure rates. It doesn't matter if your battery has the same capacity if it totally fails sooner. What was the failure rates?

 

[nicksp]

I read a few articles on that study from recurrent. The articles make it sound like supercharging is the same but I have some questions. I am learning a lot about batteries lately lol.

They are comparing these cars but how many cycles of charges and what maximum charge level?

We know charging to 90% degrades the battery a little faster alone. Surely supercharging to 90% everyday is worse than just parking in my garage at 50%

Then there is the question of failure rate. They talk about battery degradation but not failure rates. It doesn't matter if your battery has the same capacity if it totally fails sooner. What was the failure rates?

Point is they have conducted a study that says the harm is no more or no less. Your additional questions are all valid but the same could be asked of level 2 charging but there's no such study. A colleague at work is forced to SC is car every couple of days vs one who adheres to strict charging charts at home. They've both degraded equally. YMMV.

 

[AAKEE]

Point is they have conducted a study that says the harm is no more or no less. Your additional questions are all valid but the same could be asked of level 2 charging but there's no such study. A colleague at work is forced to SC is car every couple of days vs one who adheres to strict charging charts at home. They've both degraded equally. YMMV.

I am a bit sceptical from that article, judging the wear from supercharging by (most probably) range data from cars.

Research show us that fast charging causes lithium plating which is not good in the long run.

Id say that preconditioning the battery, supercharge at low SOC levels(not higher than needed) and to only use supercharging when needed or practical is a good practice.
Once, twice or fifty times does not matter. But do not do it all the time because you did read that article and bought the findings.
There is also a good probability that the pauses between times using supercharging, with normal charging and normal cycling could release some of the plated lithium and reducing the consequences.

 

[stonelance]

In my experience it took several weeks of letting the car sleep at different charge levels before the BMS recalibrated. It's a gradual process, not something that happens instantly as soon as the car sleeps then wakes once.

Yeah that seems to match my experience.

Also FWIW I can roughly match the EPA range figures when driving around my city. I get that for certain driving styles it can be impossible, but it can be achieved for some people. Living in a warm climate where you don't need the heater and traffic is pretty quiet makes a big difference.

I've seen other people claim this as well. Even in the summer I was never able to hit rated efficiency with cautious driving. The closest I ever got was on the highway driving the speed limit on ideal weather\road conditions, but it was still higher (270-280 in the summer). I wonder how much variety might exist from manufacturing\alignment differences?

 

[sjkjs]

The closest I ever got was on the highway driving the speed limit on ideal weather\road conditions, but it was still higher (270-280 in the summer). I wonder how much variety might exist from manufacturing\alignment differences?

The most efficient speed is around 70-80km/h. If you cruise at this speed and never stop you can do pretty much double the EPA range. This obviously isn't realistic driving though. In my city I spend a lot of time on quiet roads cruising at those speeds, so when you then take into account things like traffic lights, corners, etc, I can roughly get EPA quoted range when driving gently.

 

[AAKEE]

Even in the summer I was never able to hit rated efficiency with cautious driving. The closest I ever got was on the highway driving the speed limit on ideal weather\road conditions, but it was still higher (270-280 in the summer).

The best efficiency is between 20-25C temperature, if looking at logs from for example teslafi. No (or almost no) AC power is needed to keep the cabin temp.

I drove 513 km on a single charge with the average speed of 93km/h for most part of the drive, EPA range 507 km and the car had about 46K km on the ODO. The temperature was about 17C over the day.
(My car was lowered with H&R springs so probably slightly less consumption over a stock M3P.)

I wonder how much variety might exist from manufacturing\alignment differences?

Probably not much from motors/battery etc.

Wheel alignment probably can make things worse if not within spec which seems very common on Teslas as Tesla throw the cars together in a hurry. Badly worn wheels seems very common on Teslas. Anybody should make sure its correct by having a alignment performen on a new Tesla.

We need to know that the EPA test is performed with the AC/climate = OFF and at 23C temperature and the tires does have the prescibed cold pressure and the speed is not high. Also, a looong drive reduces the consumption when things get warm (battery has less losses when warm, tyre pressue higher, oil in the reduction gear thinner when warm =less losses).

 

[3sr+buyer]

The best efficiency is between 20-25C temperature, if looking at logs from for example teslafi. No (or almost no) AC power is needed to keep the cabin temp.

In moderate temperatures, I have the climate control in fan only mode (AC off, temperature set near the low end to avoid heater use). Perhaps that may be part of why I find it easy to exceed the rated economy in 65mph highway driving.

If you have the climate in automatic mode, either the heat or AC is running most the time, which tends to be a fairly useless waste of energy if the temperature is already in your comfortable range.

 

[nicksp]

In moderate temperatures, I have the climate control in fan only mode (AC off, temperature set near the low end to avoid heater use). Perhaps that may be part of why I find it easy to exceed the rated economy in 65mph highway driving.

If you have the climate in automatic mode, either the heat or AC is running most the time, which tends to be a fairly useless waste of energy if the temperature is already in your comfortable range.

I recently got about 300 miles on my 18 M3LR before I had to charge. I usually drive between 65 and 70 mph on the freeway with AC on manual on 5 speed. I agree with you about driving habits and range.

 

[AAKEE]

In moderate temperatures, I have the climate control in fan only mode (AC off, temperature set near the low end to avoid heater use). Perhaps that may be part of why I find it easy to exceed the rated economy in 65mph highway driving.

If you have the climate in automatic mode, either the heat or AC is running most the time, which tends to be a fairly useless waste of energy if the temperature is already in your comfortable range.

I wouldnt offer my comfort for that, but its of course a personal choise.

Average ambient temp at my area is 0C.
Need heating most of the days to not develope blue lips.