Do miles really matter on a Tesla being that less moving parts

[jaguar36]

Truth is, cycle life is a pure myth. Cycles don't do any damage to the battery.

Research such as this disagree. Cycles are the largest contribution to battery degradation. Cycles that stay in the middle of the batteries range, at low temperatures are much less degrading than ones that hit the extremes, but cycles still matter.

 

[DFibRL8R]

Research such as this disagree. Cycles are the largest contribution to battery degradation. Cycles that stay in the middle of the batteries range, at low temperatures are much less degrading than ones that hit the extremes, but cycles still matter.

I don't get how to apply the term "cycles" to a battery that is in a constant state of charge/discharge while driving depending on which way the electrons are flowing. Makes sense for a laptop, but not for a Tesla (even though the 2 may be using the same cell type). On a short trip, I may be putting the car through hundreds of cycles through regen. If the impact of cycles on pack longevity is significant, we should see more degradation in cars in mountainous areas or in stop and go driving right? Perhaps while there is an effect of cycles on longevity, it is minimal enough to be ignored.

 

[GJ79]

Being that I am a numbers guy, I would love to own a Tesla with like 100k plus miles since it will still have warranty on the two most pricey parts, battery and drive train. No actual engine so less chance of stuff going bad, do a lot of owners agree who may have higher mile cars?

I am on my 3rd drive unit at 75k miles and I don't expect them to last. Thank good it's under a 8 year warranty. It's definetely not a car I would like to own after the 8 years are over. Very interested on seeing though if tesla has addressed these issues in the new models.

 

[brkaus]

My 10 year old Acura has had the following problems, the least of which has been drivetrain related. Have 140k miles.

1. O2 sensor. (Changed myself for less than $100)

2. Power steering pump failed.

3. Power steering rack failed.

4. Power window on drivers side broke. $400

5. Power window in pax side broke . $400.

6. Rear shocks failed.

Plus of course tires.

 

[scaesare]

Truth is, cycle life is a pure myth. Cycles don't do any damage to the battery.

Interesting. Here's are some quotes from Tesla's whitepaper on batteries:

The bottom line is that all batteries age, and they lose capacity as they do. This, in turn, shortens driving range. Batteries age with use, and they age with time, even if not used. We tend to look at two kinds of aging: aging from use, called "cycle life," and aging with time, known as "calendar life."

Cycle Life For Li-ion cells, manufacturers define cycle life as the number of full discharge-charge cycles that it takes to reduce a cell's capacity to some fraction of its original state.

There are several factors that affect Li-ion cycle life. Some are physical and are built into the cells at the time of manufacture and so they can't be changed.

There is, of course, discussion about limiting excursions of charge and discharge, but they talk about reducing the effects of cycling, not eliminating it completely.

The ball is in your court: I look forward to seeing the supporting evidence for your assertion...

 

[kort677]

Research such as this disagree. Cycles are the largest contribution to battery degradation. Cycles that stay in the middle of the batteries range, at low temperatures are much less degrading than ones that hit the extremes, but cycles still matter.

maybe for EVs like the leaf your reports are valid, the tesla seems to suffer very minimal degradation issues.

 

[kort677]

I am on my 3rd drive unit at 75k miles and I don't expect them to last. Thank good it's under a 8 year warranty. It's definetely not a car I would like to own after the 8 years are over. Very interested on seeing though if tesla has addressed these issues in the new models.

FWIW: there are few cars on the road that don't have issues after 8 years of service

 

[jaguar36]

maybe for EVs like the leaf your reports are valid, the tesla seems to suffer very minimal degradation issues.

It depends on what you consider minimal. I consider 10% significant when compared to an ICE that has no degradation.

 

[JPUConn]

Yes - there are wear items associated with mileage but more importantly to me is that mileage leads to being out of warranty.

I'd buy a 70k mile Tesla that has a warranty til 100k vs a 35k mile
Tesla without a warranty.

 

[WarpedOne]

The ball is in your court: I look forward to seeing the supporting evidence for your assertion..

"Cycle life" has similar problems as "MIPS" that was used to represent computer speed quite some years ago.

What is a cycle? 0-100?, 40-50 ten times?, 49-50 one hundred times?
Is doing 20-21SOC the same as doing 99-100%?
Is doing that at 30degrees the same as doing it at 100?
Is doing those cycle at 1%SOC a minute the same as doing them at 10%SOC per minute?

All above scenarios differ in the 'damage' they do to the battery. Only counting how many times all the differences in SOC summed up into 100 ie one cycle is thus completely meaningless.

One might 'kill' his battery in 100 such cycles, the other could see 100.000 such cycles with a battery still going strong.

The problem is high SOC at high temperatures for long time. If one manages to avoid such scenarios, his degradation will be similar to 'calendar life'.

 

[kort677]

It depends on what you consider minimal. I consider 10% significant when compared to an ICE that has no degradation.

what tesla has had a 10% degradation?

 

[jaguar36]

what tesla has had a 10% degradation?

Have you looked at the data? Plenty of 85s report ~90% capacity. The trend is roughly 90-92% after 100k miles.

 

[kort677]

Have you looked at the data? Plenty of 85s report ~90% capacity. The trend is roughly 90-92% after 100k miles.

please highlight your sources, my s85 suffered from <1% degradation. my s90d, shows more degradation but tesla assures me that it is only a computation error.

 

[Max*]

Have you looked at the data? Plenty of 85s report ~90% capacity. The trend is roughly 90-92% after 100k miles.

I'd be curious to see the data. Everything that I've seen (all the curves), show a degradation of about 6% at 100k miles/few years down the road.

 

[Max*]

Nevermind, that was 100k km, not miles.

Tesla Model S Battery Degradation Data

Battery Degradation Level In Tesla Model S Only 5% After 30,000 Miles?

Tesla Model S battery pack data shows very little capacity loss over high mileage

 

[GJ79]

FWIW: there are few cars on the road that don't have issues after 8 years of service

I agree, but a drive unit replacement is a high dollar >10K- 15k repair. I have never encountered such a high dollar repairs on any of my ICE's even after 8 years. Don't get me wrong I love my Tesla but having an issue and pay a $1000 bucks to fix it on an ICE or having an issue that basically totals the car as the repair is more expensive than the vehicle is worth are two different things. You will see some dirt cheap Model S in 2020 when the 8 year warranty runs out.

 

[jaguar36]

please highlight your sources, my s85 suffered from <1% degradation. my s90d, shows more degradation but tesla assures me that it is only a computation error.

The aforementioned Plug In America battery survey.
Vehicle ID 62, Odo:66k Capacity:92.5%
Vehicle ID 291, Odo132k Capacity 90.5%
Vehicle ID 145, Odo 28k Capacity 90.5%
Vehicle ID 17, Odo 97k Capacity 91.6% <------- This one sits right on the trendline and is at ~100k miles.

 

[Max*]

Link to survey: Plug In America

 

[kort677]

I agree, but a drive unit replacement is a high dollar >10K- 15k repair. I have never encountered such a high dollar repairs on any of my ICE's even after 8 years. Don't get me wrong I love my Tesla but having an issue and pay a $1000 bucks to fix it on an ICE or having an issue that basically totals the car as the repair is more expensive than the vehicle is worth are two different things. You will see some dirt cheap Model S in 2020 when the 8 year warranty runs out.

yes, I agree it is a costly repair out of warranty, up to now tesla has been eating this cost because most of the units were in the warranty period. in their defense it is a breakthrough technology and this is one of the "wrinkles" of being first. I think it is only the earlier cars who have the DU issues, my newer car has been problem free.

 

[scaesare]

"Cycle life" has similar problems as "MIPS" that was used to represent computer speed quite some years ago.

What is a cycle? 0-100?, 40-50 ten times?, 49-50 one hundred times?
Is doing 20-21SOC the same as doing 99-100%?
Is doing that at 30degrees the same as doing it at 100?
Is doing those cycle at 1%SOC a minute the same as doing them at 10%SOC per minute?

All above scenarios differ in the 'damage' they do to the battery. Only counting how many times all the differences in SOC summed up into 100 ie one cycle is thus completely meaningless.

One might 'kill' his battery in 100 such cycles, the other could see 100.000 such cycles with a battery still going strong.

The problem is high SOC at high temperatures for long time. If one manages to avoid such scenarios, his degradation will be similar to 'calendar life'.

From that same whitepaper:

. Cycle Life For Li-ion cells, manufacturers define cycle life as the number of full discharge-charge cycles that it takes to reduce a cell's capacity to some fraction of its original state.

The depth-of-discharge is discussed in a number of places as well. For example see the tables HERE

Again, you assert that cycling impact is "a pure myth", and that "Cycles don't do any damage to the battery." Please to be providing any underlying research or references that cycling (at whatever depth) has zero impact on a li-ion cell.