Tesla model Y 4680 battery pack not very serviceable!

[MT]

part2


part1

[cpuerror]

Its 2022. You can only subscribe to things and the few things you can own are designed to self destruct after a period of time.

[tom66]

Poor design.  Such an essential component that will eventually wear out should be serviceable, even if it increases weight and cost.  I'd also like to see EV manufacturers forced to offer a 15 year warranty on their batteries with 70% capacity remaining.

[nctnico]

Poor design.  Such an essential component that will eventually wear out should be serviceable, even if it increases weight and cost.  I'd also like to see EV manufacturers forced to offer a 15 year warranty on their batteries with 70% capacity remaining.

This is a pretty big fail from Tesla... AFAIK most (in not all) other BEV manufacturers do have battery packs that consist of serviceable cells / sub-modules that make a battery economically repairable and thus make a BEV retain its value better. But then again: Tesla is the Apple of cars; serviceability doesn't matter to their customers.

[SiliconWizard]

Well, uh... interesting point.

Maybe other manufacturers have more "serviceable" battery packs - although I personally have no proof of that.
But are any of those batteries actually serviced in reality? Has it ever happened? Has it not just because it's too early for any of them to have failed yet? And in this latter case, how do we actually know for sure manufacturers will service them instead of just binning them and having them recycled?

Yeah, just a thought. I have some doubts.

[bdunham7]

But are any of those batteries actually serviced in reality? Has it ever happened? Has it not just because it's too early for any of them to have failed yet? And in this latter case, how do we actually know for sure manufacturers will service them instead of just binning them and having them recycled?

Actually yes!  My 2014 Ford Focus Electric BEV just received a 'remanufactured' battery as a repair for an internal coolant leak.  Apparently the coolant leak is pretty much the main problem these batteries have--I had noticed only minor degradation after almost 50K miles.  In any case, they are sent back to some supplier where they repair, refurbish and test them.  From what I've seen in descriptions and teardowns, the battery units on these are completely serviceable and can be disassembled with normal tools.  The downside is that a 23kWh battery weighs ~600 lbs.  The newer ones are 33.5kWh at the same weight, so perhaps that isn't too terrible considering the serviceability. 

[tszaboo]

Poor design.  Such an essential component that will eventually wear out should be serviceable, even if it increases weight and cost.  I'd also like to see EV manufacturers forced to offer a 15 year warranty on their batteries with 70% capacity remaining.

This is a pretty big fail from Tesla... AFAIK most (in not all) other BEV manufacturers do have battery packs that consist of serviceable cells / sub-modules that make a battery economically repairable and thus make a BEV retain its value better. But then again: Tesla is the Apple of cars; serviceability doesn't matter to their customers.

Realistically, the battery lasts longer than the car. But then you get a failure in one, maybe two cell on the bathtub curve and you end up scrapping most of the car? For sure it's a total loss, repairing Teslas was always stupidly expensive.

[nctnico]

Well, uh... interesting point.

Maybe other manufacturers have more "serviceable" battery packs - although I personally have no proof of that.

If you Google around a bit you'll find many companies that refurbish BEV and hybrid batteries. This is a mature business!

[Coordonnée_chromatique]

Realistically, the battery lasts longer than the car.

Could you give some examples of reliable statistics please ?

[tszaboo]

Realistically, the battery lasts longer than the car.

Could you give some examples of reliable statistics please ?

Sure, but you could just google it yourself.

[SiliconWizard]

Over 90% after 250 000 km... yeah. Really?

[tom66]

Actually yes!  My 2014 Ford Focus Electric BEV just received a 'remanufactured' battery as a repair for an internal coolant leak.  Apparently the coolant leak is pretty much the main problem these batteries have--I had noticed only minor degradation after almost 50K miles.  In any case, they are sent back to some supplier where they repair, refurbish and test them.  From what I've seen in descriptions and teardowns, the battery units on these are completely serviceable and can be disassembled with normal tools.  The downside is that a 23kWh battery weighs ~600 lbs.  The newer ones are 33.5kWh at the same weight, so perhaps that isn't too terrible considering the serviceability.

Also from the VW camp my car had its battery pack replaced under warranty due to bad sealing, but many others have had just casing refurbished.  Growing pains as car manufacturers figure out how to make batteries properly.

Over 90% after 250 000 km... yeah. Really?

Why not?  At 80kWh capacity per charge and 5km/kWh 250,000 km is 625 cycles.  A good Li-Ion pack will do 1500 cycles easily, a very good Li-Ion pack can do 3000.

[jmelson]

Well, uh... interesting point.

Maybe other manufacturers have more "serviceable" battery packs - although I personally have no proof of that.
But are any of those batteries actually serviced in reality? Has it ever happened? Has it not just because it's too early for any of them to have failed yet? And in this latter case, how do we actually know for sure manufacturers will service them instead of just binning them and having them recycled?

I just got a rebuilt battery pack for my Hondas Civic hybrid.  Way smaller than this Tesla pack, of course, but it is built out of battery submodules, 10 cells/module.  The Honda pack is air cooled, so that is a big difference.
Jon

[MT]

Well, uh... interesting point.
Maybe other manufacturers have more "serviceable" battery packs - although I personally have no proof of that. But are any of those batteries actually serviced in reality? Has it ever happened? Has it not just because it's too early for any of them to have failed yet? And in this latter case, how do we actually know for sure manufacturers will service them instead of just binning them and having them recycled?

Yeah, just a thought. I have some doubts.

Rich Rebuilds Tesla wanted $16,000 to fix this NEW Model 3, we did it for $700! The importance of Right to REPAIR
From 4:57 and forward, 5000usd bat module change and coolant nipple fix etc.

[tautech]

Finnish remedy:
https://edition.cnn.com/videos/us/2021/12/30/tesla-exploded-dynamite-repair-costs-22k-moos-pkg-vpx.cnn

[Psi]

Realistically, the battery lasts longer than the car.

Could you give some examples of reliable statistics please ?

Sure, but you could just google it yourself.
<IMAGE>

Over 90% after 250 000 km... yeah. Really?

Hm.. i'm not sure if that graph takes into account the cars that have software limited battery capacity.
I mean the cars that received a large battery pack but were sold as lower range cars with range software limited to match the model that was purchased.  I'm pretty sure those cars use the extra capacity to compensate for aging, so they appear to last forever because you don't notice any loss in range until the pack is like 60% deteriorated and it starts eating into your software usable range. Also those cars don't get their batteries charged/discharged to as wide of a voltage range so that helps a lot too.

[tom66]

Hm.. i'm not sure if that graph takes into account the cars that have software limited battery capacity.
I mean the cars that received a large battery pack but were sold as lower range cars with range software limited to match the model that was purchased.  I'm pretty sure those cars use the extra capacity to compensate for aging, so they appear to last forever because you don't notice any loss in range until the pack is like 60% deteriorated and it starts eating into your software usable range. Also those cars don't get their batteries charged/discharged to as wide of a voltage range so that helps a lot too.

Only the very early Teslas had software limited packs.  There are caps either side of the pack at like 3V/cell and 4.2V/cell but those are more 'anti-bricking' than any capacity reservation.

[nctnico]

Over 90% after 250 000 km... yeah. Really?

There are a whole bunch of outliers in the graph that show you can get seriously unlucky and buy a lemon battery pack. Also the amount of data for high mileage numbers is minimal.

[tom66]

There are a whole bunch of outliers in the graph that show you can get seriously unlucky and buy a lemon battery pack. Also the amount of data for high mileage numbers is minimal.

Boy, it sure is good that there's an entire field of statistics based on the idea of statistical distributions that allows you to infer data into the future. 

And of course, everyone knows lemon products are not seen in any other field other than electric cars. 

[nctnico]

There are a whole bunch of outliers in the graph that show you can get seriously unlucky and buy a lemon battery pack. Also the amount of data for high mileage numbers is minimal.

Boy, it sure is good that there's an entire field of statistics based on the idea of statistical distributions that allows you to infer data into the future. 

But you have to factor in the nature of the device you are deriving statistics from. At some point Li-ion batteries start to lose capacity exponentially. You can imagine a straight line going down gradually but that is a fantasy. So again: there is data missing to draw a definitive conclusion. The graph should have included error bars; that would show an entirely different picture.

And of course, everyone knows lemon products are not seen in any other field other than electric cars.

That is not the point    The point is that cars (or any item) can have defects. Some are more costly to fix than others based on construction. Looking at the graph the chance that you buy a Tesla with a bad battery is around 1 in 1000.

[tom66]

But you have to factor in the nature of the device you are deriving statistics from. At some point Li-ion batteries start to lose capacity exponentially. You can imagine a straight line going down gradually but that is a fantasy. So again: there is data missing to draw a definitive conclusion. The graph should have included error bars; that would show an entirely different picture.

Do they?   Why would cell degradation be exponential and not just linear?  The cause of Li-ion deterioration is contaminants building up at the SEI layer, which limits the amount of charge and discharge progressively.  You can model this with coloumbic inefficiency; Panasonic chemistries have a very low CI figure.  I see no reason this has to be an exponential failure, especially if the cell is kept within reasonable temperature ranges and has a stable chemistry.  Heck, even the shittiest Nissan batteries have near-linear degradation. (https://flipthefleet.org/wp-content/uploads/2018/07/decay_comparison.png)

That is not the point    The point is that cars (or any item) can have defects. Some are more costly to fix than others based on construction. Looking at the graph the chance that you buy a Tesla with a bad battery is around 1 in 1000.

And I'm sure there's a 1 in 1000 chance of something bad happening with an ICE engine - owning a car is always a risk.  I know people with ICE cars, perfectly serviced, which have burned to the ground in the night for no good reason.  Or cars that randomly throw a rod just outside of warranty.  I do agree that Tesla needs to make their packs more serviceable but I don't think the chance of failure is so high that it can't be mitigated.  There will certainly be a good after-market for battery warranties, and battery service, once EVs become more dominant, just as there are gearbox/engine rebuild companies now.

[Someone]

There are a whole bunch of outliers in the graph that show you can get seriously unlucky and buy a lemon battery pack. Also the amount of data for high mileage numbers is minimal.

Boy, it sure is good that there's an entire field of statistics based on the idea of statistical distributions that allows you to infer data into the future. 

And of course, everyone knows lemon products are not seen in any other field other than electric cars.

Also, graph cutting off the y axis at 85% remaining capacity. Not 0%, still completely usable! Given things like fast charging are going to reduce capacity it is not surprising that there is spread. Given they are chemical batteries (without a significant opportunity for binning??) the spread is impressively small! Prius' with their more heavily cycled battery were getting 150,000 to beyond 300,000 km before requiring replacement.

[PeteH]

Some additional data here (Tesla Model 3, Long Range, 2018). DC fast charging (supercharging) about 6.7% of total kWh charged. Range at time of purchase was rated at ~499km.

Edit: added another 3rd party tool's data.

[tszaboo]

Realistically, the battery lasts longer than the car.

Could you give some examples of reliable statistics please ?

Sure, but you could just google it yourself.
<IMAGE>

Over 90% after 250 000 km... yeah. Really?

Hm.. i'm not sure if that graph takes into account the cars that have software limited battery capacity.
I mean the cars that received a large battery pack but were sold as lower range cars with range software limited to match the model that was purchased.  I'm pretty sure those cars use the extra capacity to compensate for aging, so they appear to last forever because you don't notice any loss in range until the pack is like 60% deteriorated and it starts eating into your software usable range. Also those cars don't get their batteries charged/discharged to as wide of a voltage range so that helps a lot too.

The toyota prius battery pack was microcycled for at test. They used the usual between 40-60% DoD that the car is using for it's ~2km range. They did as I remember over 100.000 cycles with it, which is like 200.000 km electric only.
Most EVs have better lithium batteries. And it's not like your cal becomes unusable with a 80% battery pack. Even Nissan Leafs which had badly designed batteries with insufficient cooling often have 80% left after 6-7 years.

[tom66]

My GTE battery is going on for 1200 cycles (25 miles range, 40000 miles but some on petrol so assume 30000 miles on EV) and still shows capacity of around 93.5% of original.  That pack is discharged up to 10C under hard acceleration and regen is ~5C peak.  It is however liquid cooled and uses Panasonic cells.  I am pretty sure even a PHEV pack could do 200k miles to 70% capacity although this might be a good reason not to get a PHEV over BEV - I would imagine the BEV battery will last longer (but the PHEV does have the engine as a backup)