Warranty on Battery

[Thunderbird1]

If your Battery or Drive Unit requires warranty repair, Tesla will repair the unit, or replace it with a new, reconditioned or re-manufactured part at the sole discretion of Tesla. The warranty replacement may not restore the vehicle to a "like new" condition, but when replacing a Battery, Tesla will ensure that the energy capacity of the replacement Battery is at least equal to that of the original Battery before the failure occurred while taking into consideration other factors, including the age and mileage of the vehicle.

How do they not restore the battery "like new" then ?
Also 4 years is useful but is not unlimited mileage....

 

[Jason71]

The warranty on the battery is 8 years 100k (SR+) 120K (LR/P) the 4 years is the general warranty and does not relate to the battery

The wording you are looking at is predicated on the assumption of a complete failure rather than a gradual degradation
i.e if the data shows your battery was at 90% original capacity then it fails somehow they are promising to replace it with a battery that has at least 90% capacity.

Under the circumstance of a gradual degradation where it gradually goes down and hits 69% at 7.5 years I have no idea how that statement would be applied. In theory they could give you another battery that was at 75% capacity to get you over the line to 8 years. In practice that seems unlikely. not least because they would not have piles of batteries at 75% kicking around. As far as I am aware, in reality, battery replacements are generally a new battery.
I guess its the same as an ICE engine failures and they replace it with a reconditioned engine rather than new. Which is definitely a thing, as are reconditioned replacement phones for warranty claims.

 

[Adopado]

If your Battery or Drive Unit requires warranty repair, Tesla will repair the unit, or replace it with a new, reconditioned or re-manufactured part at the sole discretion of Tesla. The warranty replacement may not restore the vehicle to a "like new" condition, but when replacing a Battery, Tesla will ensure that the energy capacity of the replacement Battery is at least equal to that of the original Battery before the failure occurred while taking into consideration other factors, including the age and mileage of the vehicle.

How do they not restore the battery "like new" then ?
Also 4 years is useful but is not unlimited mileage....

The battery isn't one thing that necessarily needs to be replaced as a whole. It includes a management system, cooling/warming system, and lots of individual cells. The fault may be in any of those sections. If 99% of that lot is OK then they will replace the bits that need to be replaced and send you on your way. I would also predict that when the whole battery pack is underperforming this does not mean that all the cells are evenly deteriorating. It's more likely that a few cells are out of spec and the management system then has to run the whole battery at a lower level to protect them ... so replace those cells and you're good to go. You would have a much better performing battery afterwards but obviously it's still going to be the age it is. There's no justification to put in a whole new battery at massive expense if they don't have to.

(In practice the repair is likely to be done but you get a similar age "good" battery slotted in and your old battery goes to someone else.)

 

[tsh2]

Cells also come in modules, generally one cell within a module in a pack in a battery will fail (in 100's of car.years) so a single 'failed' battery likely provides the donor parts to fix at least 10 others. As long as the replacement module is 'younger' than the rest in the battery, it doesn't need to be new.

 

[ewoodrick]

They are reconditioning battery packs as they are turned in. They'll replace bad batteries/packs as possible and put it all back together. At that point, the battery is in much better shape than it was before, but less than 100%. It's a little bit like pixels on a TV, some are within warranty, but too make it a warranty issue.

A common assumption is that a individual battery cell slowly goes from 100% to 0%, that's not really the case. At the beginning, there's a slight drop as the individual battery cell gets to it steady state, after that it stays there a long time until it fails. It's the failed individual battery cell that are the problem.

So you get a battery with many/most of the failed cells replaced, but they have age on them.

That's why tires and 12V batteries have prorated warranties. It's basically the same thing.

 

[Roy W.]

From what I’ve read, Tesla batteries are very durable compared to some of the other EV batteries. Apart from their design and chemistry, I think a lot of this durability is down to the active thermal management of the battery.

Most other EVs either have no active thermal management (Nissan Leaf), or they have a less effective system compared to Tesla’s.

Several years ago I had a 24 kWh Leaf on a two year PCP. I really didn’t mollycoddle the battery - charged to 100% every time, lots of DC rapid charging. But after the two years and 20k miles the battery had lost less than 2% capacity according to Leaf Spy. I hoping the Model 3 can improve in that performance.

 

[ewoodrick]

From what I’ve read, Tesla batteries are very durable compared to some of the other EV batteries. Apart from their design and chemistry, I think a lot of this durability is down to the active thermal management of the battery.

Most other EVs either have no active thermal management (Nissan Leaf), or they have a less effective system compared to Tesla’s.

Several years ago I had a 24 kWh Leaf on a two year PCP. I really didn’t mollycoddle the battery - charged to 100% every time, lots of DC rapid charging. But after the two years and 20k miles the battery had lost less than 2% capacity according to Leaf Spy. I hoping the Model 3 can improve in that performance.

A 2% loss is often just a settling in number. It'd probably be a lot more than 5 years before it drops much more.
And while the batter management that Tesla implement is definitely expected to help the battery life. I'm starting to feel like they may have gone a little overboard with the latest updates. Last year, rarely would see the limited regen notification, this week I saw it with less than 50% charge.
They are starting to creep into drivability issues.

And to think that my 2018 Leaf doesn't have these issues. And my 2015 Leaf (also around 2% loss when I got rid of it) didn't have the issues also)

And on the Leaf rant, yes, early Leaf batteries had some issues. But guess what, so did the early Tesla batteries. Since then, AFAIK, the only issue with Leaf batteries (with passive thermal management) has been summer time, long range travel with Supercharging. Something that rarely do people do anyway. It just slowed charging to slightly less, significantly higher than the Tesla batterygate batteries.