Battery replacement question

[Volund]

I was having a discussion with my cousin who's a Tesla owner, one of the things we discussed was comparing an engine in a typical ICE vehicle and costs to a battery in an EV.

Correct me if I'm wrong, but the battery cells are small cells that are linked together in a battery pack, and there are multiple battery packs that work in synergy to deliver the electricity.

Now, if yoy have cells that are going bad in a battery pack, would you need to replace the entire battery and all packs, or just that single battery pack out of the many?

My cousin said for Tesla, you have to replace everything and it's not modular.
He's also worked for Tesla recently so I am also giving him the benefit of the doubt.
Any news article that speaks about battery replacement use the term "battery replacement" as a singular term so it's difficult to decipher whether or not a single pack was replaced or the whole thing and all packs.

This would have an immense difference in cost depending on if it's modular or not (which I believe it is and even looking at Lucid's design, seems to be that way)

Because a single pack can be thousands or even ten thousand versus 50k+ or more for the whole thing depending on kw size of the whole pack.

Anyone have insight?

 

[Steveinarizona]

I had a BMW PHEV before my current car. It had a battery failure. Based on BMW's public information, I expected that they would just replace the bad batteries. But they replaced the entire battery pack. I am guessing that somewhere along the line the bad batteries are removed and the good ones are recycled and used. Not sure where or how they reuse a part without disclosing it. Perhaps they come back to the auto manufacturer for replacements. But this is all surmise on my part.

 

[Pax]

Tesla battery packs, along with Rivian and many other EV automakers, treat the battery pack as one single unit. This is because either due to how it's packaged or built, it's incredibly difficult to have re-use because of the insulation, cooling, glueing, etc. used to create the battery pack.

Lucid uses a battery pack composed of modules. It'll be easy for them to replace the entire battery pack as a whole like the other EV automakers but they could in theory replace certain module(s) instead if there's a fault somewhere. However, for consumers sake I think they'll replace the whole battery pack for now and repurpose the individual modules after investigating what went wrong.

 

[borski]

I was having a discussion with my cousin who's a Tesla owner, one of the things we discussed was comparing an engine in a typical ICE vehicle and costs to a battery in an EV.

Correct me if I'm wrong, but the battery cells are small cells that are linked together in a battery pack, and there are multiple battery packs that work in synergy to deliver the electricity.

Now, if yoy have cells that are going bad in a battery pack, would you need to replace the entire battery and all packs, or just that single battery pack out of the many?

My cousin said for Tesla, you have to replace everything and it's not modular.
He's also worked for Tesla recently so I am also giving him the benefit of the doubt.
Any news article that speaks about battery replacement use the term "battery replacement" as a singular term so it's difficult to decipher whether or not a single pack was replaced or the whole thing and all packs.

This would have an immense difference in cost depending on if it's modular or not (which I believe it is and even looking at Lucid's design, seems to be that way)

Because a single pack can be thousands or even ten thousand versus 50k+ or more for the whole thing depending on kw size of the whole pack.

Anyone have insight?

They can replace a single module. Whether they will seems unlikely; I imagine they would rather collect all the modules (a single “battery pack” and then remanufacture them as a new battery “pack” for future use).

This is a fantastic breakdown if you haven’t watched it:

 

[Volund]

I've seen that one, I love Peter Rawlinson's explanation and it's highly educational.

My only gripe is that if a module isn't replaceable, the cost will be order of magnitudes different if something goes wrong. Which seems likely. I hope in the next 8-10 years of our battery warranty that they figure out how to replace modules because then it seems long term keeping EV's would be very expensive if you estimate a new battery pack every 8 years, I'd guesstimate 50k at least for Lucid's battery pack.

 

[DreamTour]

I've seen that one, I love Peter Rawlinson's explanation and it's highly educational.

My only gripe is that if a module isn't replaceable, the cost will be order of magnitudes different if something goes wrong. Which seems likely. I hope in the next 8-10 years of our battery warranty that they figure out how to replace modules because then it seems long term keeping EV's would be very expensive if you estimate a new battery pack every 8 years, I'd guesstimate 50k at least for Lucid's battery pack.

Lucid's packs aren't any bigger than the competition's. BOM is probably like ~$20k ish for the 84-88kwh pack. Their thesis is smaller packs = how to drive down EV cost.

8-10 years down the road in reality you'd be buying used / remanufactured packs too as new would have moved on to new chemistry. So probably replacement is less than you think.

 

[hydbob]

Lucid has already been replacing modules in entire packs.

 

[maractwin]

I have seen a YouTuber talk about third party Tesla repair. Someone brought in one that Tesla insisted needed a new $22,000 battery pack. This third-party garage was able to identify which of the dozen or so modules had the fault and pull just that one. They opened the sealed module (in a semi-destructive way so that it's future water proofedness was suspect) and could see the failed cell by visual inspection. While the car got fully repaired, Tesla revoked that vehicle's permission to use the supercharger network because it had undergone third-party repair.

 

[borski]

I have seen a YouTuber talk about third party Tesla repair. Someone brought in one that Tesla insisted needed a new $22,000 battery pack. This third-party garage was able to identify which of the dozen or so modules had the fault and pull just that one. They opened the sealed module (in a semi-destructive way so that it's future water proofedness was suspect) and could see the failed cell by visual inspection. While the car got fully repaired, Tesla revoked that vehicle's permission to use the supercharger network because it had undergone third-party repair.

Honestly, if I were Tesla, I’d have done the same. I would much, much rather replace the entire pack and refurbish it than risk the liability of an explosion due to poorly closing the package.

Lucid’s packs are all custom molded and pressed, not soldered. They could easily replace a module.

If I were them, I still wouldn’t.

 

[maractwin]

I was going to respond to some of the details, but this isn't a Tesla forum and they don't really matter. The point is, from an engineering standpoint these are repairable, but by policy they are not. That probably won't change until the press quits sensationalizing every EV fire, even though they happen less often per mile driven than gasoline engine fires.

 

[hmp10]

Rivian is the only EV maker I've seen publish the fact that individual modules can be replaced, and that was during the early days before production began. I don't know if that still holds true.

I'm no engineer, but I've encountered references to having to "balance" the cells within a pack. It's my understanding that, in using thousands of small cells designed to power laptop computers, one of the first problems Tesla had to solve was keeping so many cells in balance. (One of the early delays in bringing long-range EVs to market was the wait for large-capacity cells for automotive applications to be developed. Musk's key inspiration was to short-circuited the wait by surmising that perhaps existing computer cells could be utilized if the balance problem could be solved.)

I'm wondering if that means there could be a problem in mixing new cells into a pack with older cells that have experienced some degradation?

 

[Volund]

I have seen a YouTuber talk about third party Tesla repair. Someone brought in one that Tesla insisted needed a new $22,000 battery pack. This third-party garage was able to identify which of the dozen or so modules had the fault and pull just that one. They opened the sealed module (in a semi-destructive way so that it's future water proofedness was suspect) and could see the failed cell by visual inspection. While the car got fully repaired, Tesla revoked that vehicle's permission to use the supercharger network because it had undergone third-party repair.

Honestly, if I were Tesla, I’d have done the same. I would much, much rather replace the entire pack and refurbish it than risk the liability of an explosion due to poorly closing the package.

Lucid’s packs are all custom molded and pressed, not soldered. They could easily replace a module.

If I were them, I still wouldn’t.

To comment on the first part, my cousin who works for Tesla did also say he has personally seen third party shops hack the software of their Tesla and they basically jailbreak them and allow supercharging access. It's common and many shops do it.