Replacement Battery Model 3 long range with 22K miles.

[mvill]

I need some perspectives to help me get my mind wrapped around how Tesla handles service.

Situation:
Last week my partner ran over a deer that had been hit earlier causing the lines coolant to leak. The car drove and handled well, but gave the "Slow down" warning. We had it towed to a Tesla service center who said that the lines that feed the battery were damaged.
They say they can not fix the lines so we need to replace the entire battery assembly that is otherwise undamaged (part cost $13.5K).
Q1) Is there anyone who will replace just the coolant lines feeding the battery?
Q2) If so, does this affect the warranty?
Also, though we are paying for a replacement assembly $13.5K in full, they will not allow us to keep the "Damaged" part claiming it is "Restricted part".
Q3) Is this legal, can they really say that something I bought, I can not have? Been working on ICU vehicles 30 yrs and this has never heard anything like this.
Q4) When we do replace it, how do we make sure we get a like conditioned unit that has almost never been charged over 80% and only has 22K on it?

Thanks for your perspective.

 

[theothertom]

Try reaching out to Gruber Motors or Rich Rebuilds

 

[LamboM3P]

I need some perspectives to help me get my mind wrapped around how Tesla handles service.

Situation:
Last week my partner ran over a deer that had been hit earlier causing the lines coolant to leak. The car drove and handled well, but gave the "Slow down" warning. We had it towed to a Tesla service center who said that the lines that feed the battery were damaged.
They say they can not fix the lines so we need to replace the entire battery assembly that is otherwise undamaged (part cost $13.5K).
Q1) Is there anyone who will replace just the coolant lines feeding the battery?
Q2) If so, does this affect the warranty?
Also, though we are paying for a replacement assembly $13.5K in full, they will not allow us to keep the "Damaged" part claiming it is "Restricted part".
Q3) Is this legal, can they really say that something I bought, I can not have? Been working on ICU vehicles 30 yrs and this has never heard anything like this.
Q4) When we do replace it, how do we make sure we get a like conditioned unit that has almost never been charged over 80% and only has 22K on it?

Thanks for your perspective.

Assuming you have full coverage would this be treated as if you had hit the deer proper and suffered body and glass damage? Put the claim in. Also if this was on a State road you might have other avenues available in court

 

[mvill]

This is probably what you broke. For some reason Tesla replaces the whole battery if you break the hose connector in the front. If you run something over it's going to hit the front of the battery. Front of the battery is this coolant line. It's not even a difficult fix.

I think what's happening is Tesla doesn't really have mechanics that solve problems. They have techs that just follow instructions and replace modules. They probably send the battery to depot level maintenance and they replace the connector.

This is exactly what I was thinking. So the end result is ridiculously high cost of repair and higher insurance rates for anyone who wants a tesla.

Crazy!!

 

[ElectricNerd]

What does Tesla do with those battery packs once they replace them? They could use the individual cells to help fix older battery packs.

 

[MP3Mike]

What does Tesla do with those battery packs once they replace them?

They repair them if they can. (If it is an electronics problem, or coolant plumbing that can be fixed.)

They could use the individual cells to help fix older battery packs.

No they can't. Cells in a pack have to be perfectly matched, you can't replace cells. If a cell fails in a Model 3/Y pack, as far as I have seen, the entire pack has to be recycled. (I don't think that Tesla does "second-life" usage, like using good modules from a failed pack for stationary storage.)

 

[mvill]

Good point. I will ask them and report back.

They say that it is only and extra $500 for a brand new one. Doesn't that seem like a no brainer?

 

[3sr+buyer]

No they can't. Cells in a pack have to be perfectly matched, you can't replace cells. If a cell fails in a Model 3/Y pack, as far as I have seen, the entire pack has to be recycled. (I don't think that Tesla does "second-life" usage, like using good modules from a failed pack for stationary storage.)

Since Tesla provides remanufactured packs for warranty or other replacements, it is likely that old pack components were reused. Components other than the cells can certainly be reused if undamaged.

Also, given that replacement packs have been observed with less than new capacity (but enough capacity to be at least as good as the replaced packs), it does appear that they may contain old cells.

 

[davewill]

What does Tesla do with those battery packs once they replace them? They could use the individual cells to help fix older battery packs.

They probably go into the remanufacturing program and whatever parts are usable in a reman pack are reused. If the only damage is to the coolant connector, there's a decent chance they just replace the fitting, run it through testing, and send it back out.

I also expect there are reuse cases for packs too degraded for the reman program, but I'm not sure what Tesla is currently doing. Think power backup for commercial buildings, or public utilities.

 

[3sr+buyer]

I also expect there are reuse cases for packs too degraded for the reman program, but I'm not sure what Tesla is currently doing. Think power backup for commercial buildings, or public utilities.

Seems like such packs can be reused by removing degraded cells and putting new (or better used) cells in.

 

[MP3Mike]

Seems like such packs can be reused by removing degraded cells and putting new (or better used) cells in.

No they can't. For at least a couple reasons:

• You can't just remove and replace a cell, they are glued in and the contacts are all spot welded, and then foamed in place. It would be a major undertaking to unwire the whole module remove a cell, put a new one in, and then rewire it.
• All of the cells in the pack have to be perfectly matched. (Capacity, voltage, internal resistance, etc.)

As I have said before, if a cell fails in a pack the only option is to recycle all of the modules/cells in it. (At least if you want to use it in a Tesla, if you want to hack it for some non-Tesla purpose like off-grid storage you could, but you would have balancing issues.) The only exception is for the "older" 16 module Model S/X packs, where you could remove 2 bad modules leaving the remaining 14 matched modules to make a smaller refurbished pack.

 

[AlanSubie4Life]

No they can't. For at least a couple reasons:

• You can't just remove and replace a cell, they are glued in and the contacts are all spot welded, and then foamed in place. It would be a major undertaking to unwire the whole module remove a cell, put a new one in, and then rewire it.
• All of the cells in the pack have to be perfectly matched. (Capacity, voltage, internal resistance, etc.)

As I have said before, if a cell fails in a pack the only option is to recycle all of the modules/cells in it. (At least if you want to use it in a Tesla, if you want to hack it for some non-Tesla purpose like off-grid storage you could, but you would have balancing issues.) The only exception is for the "older" 16 module Model S/X packs, where you could remove 2 bad modules leaving the remaining 14 matched modules to make a smaller refurbished pack.

I have not seen @wk057 comment on this but presumably in the event of a bad cell you could snip one cell out of every brick (including a bunch of good ones) and then have good balance at the cost of (2170 78-82kWh) 2.2% capacity for these off-grid power hacks. Maybe something prevents it. But anyway that is not much of a refurbishment and Tesla won’t be doing that!

 

[3sr+buyer]

No they can't. For at least a couple reasons:

• You can't just remove and replace a cell, they are glued in and the contacts are all spot welded, and then foamed in place. It would be a major undertaking to unwire the whole module remove a cell, put a new one in, and then rewire it.
• All of the cells in the pack have to be perfectly matched. (Capacity, voltage, internal resistance, etc.)

While one cell is difficult to replace, wouldn't it be easily possible to replace one or more of the four modules (with all of the cells contained therein) in the same battery housing?

Seems like old housings with replaced modules (including cells) would be a source of the supply of remanufactured packs.

 

[MP3Mike]

While one cell is difficult to replace, wouldn't it be easily possible to replace one or more of the four modules (with all of the cells contained therein) in the same battery housing?

Sure, you could easily replace it, but it won't work long term because the BMS won't be able to keep it in balance with the other modules because it isn't perfectly matched to them. (And actually for the 4680 packs, you couldn't easily replace it.)

 

[wk057]

I have not seen @wk057 comment on this but presumably in the event of a bad cell you could snip one cell out of every brick (including a bunch of good ones) and then have good balance at the cost of (2170 78-82kWh) 2.2% capacity for these off-grid power hacks. Maybe something prevents it. But anyway that is not much of a refurbishment and Tesla won’t be doing that!

You could, in theory, "remove" a cell from all 96 groups, and the pack would remain balanced.

However, in practice this is unlikely to work in a vehicle in the case of a truly bad cell in a group, since that cell would have been causing problems for the entire cell group over some extended period of time. That entire group would very likely still have a large capacity delta as a result, even if the bad cell and 95 other cells in the pack were removed to attempt to balance it.

Overall, it's not a process you really want to bother with. At best it's a short term fix, and at worst a massive waste of time and money. Actually, it's generally the latter regardless.

 

[3sr+buyer]

Sure, you could easily replace it, but it won't work long term because the BMS won't be able to keep it in balance with the other modules because it isn't perfectly matched to them. (And actually for the 4680 packs, you couldn't easily replace it.)

Since minor differences in cell degradation (and hence module degradation) can occur over time, shouldn't the BMS be able to handle a pack whose cells or modules are no longer perfectly balanced (though it could result in the worst cell or module being the limitation on capacity)?

 

[MP3Mike]

Since minor differences in cell degradation (and hence module degradation) can occur over time, shouldn't the BMS be able to handle a pack whose cells or modules are no longer perfectly balanced (though it could result in the worst cell or module being the limitation on capacity)?

No, because the whole pack is subject to the same use, temperature, time, etc. So they all degrade at the same rate and remain matched.

 

[SR123]

This is probably what you broke. For some reason Tesla replaces the whole battery if you break the hose connector in the front. If you run something over it's going to hit the front of the battery. Front of the battery is this coolant line. It's not even a difficult fix.

I think what's happening is Tesla doesn't really have mechanics that solve problems. They have techs that just follow instructions and replace modules. They probably send the battery to depot level maintenance and they replace the connector.

No offense dude but this guy has a car that cost him more than 40k. An expensive car isn't something you'd fiddle with for fun. In my opinion, this problem is best left to professionals

 

[3sr+buyer]

No, because the whole pack is subject to the same use, temperature, time, etc. So they all degrade at the same rate and remain matched.

You think Tesla would not design the BMS to account for cell imbalances? Especially since, from the early days, they knew that quality control was not perfect, and had to design fire resistance features into the pack so that a single cell failure would not light the entire pack on fire. Obviously, a cell that failed (but did not light the entire pack on fire) would cause an imbalance afterward; since Tesla is aware of such a possibility, it would have to design the BMS to handle that situation.

Similarly, why would it be impossible for some cells to degrade at different rates (even if they did not suffer a complete failure) due to manufacturing defects?

 

[MP3Mike]

You think Tesla would not design the BMS to account for cell imbalances? Especially since, from the early days, they knew that quality control was not perfect, and had to design fire resistance features into the pack so that a single cell failure would not light the entire pack on fire. Obviously, a cell that failed (but did not light the entire pack on fire) would cause an imbalance afterward; since Tesla is aware of such a possibility, it would have to design the BMS to handle that situation.

Well the fact is that the BMS system can't handle one bad cell being removed from a brick. (Well it can if you don't drive the car very much, and don't go on any trips powered by Superchargers.)

FYI: In the 4680 packs, losing one cell would mean losing 11% of the pack capacity.

Similarly, why would it be impossible for some cells to degrade at different rates (even if they did not suffer a complete failure) due to manufacturing defects?

The BMS can only handle a very minor difference between bricks. It is possible, and it would result in the pack being replaced as failed. (But it seems like that doesn't happen very often, if at all. Which may be because of very good QA on the produced cells.)

 

[stopcrazypp]

Well the fact is that the BMS system can't handle one bad cell being removed from a brick. (Well it can if you don't drive the car very much, and don't go on any trips powered by Superchargers.)

FYI: In the 4680 packs, losing one cell would mean losing 11% of the pack capacity.

Maybe the BMS is much weaker in the Model 3 (Tesla did reduce phantom drain a lot), but from the Roadster days, my understanding is that each group of parallel cells (a brick) functions as a unit, so as long as cells are well matched in a group, it would work fine. You just do a rough manual balance before reassembling the pack.

The whole point of balancing is to handle differences in capacity among groups, so it's actually expected they aren't perfectly matched (although from factory they obviously try to ensure they are as close as possible, to minimize the amount balancing required, and to ensure maximum capacity).

Yes, you do lose capacity proportional to the amount of cells in parallel (in Roadster that means 1/69 if you lose one cell). Basically the total pack would be limited by the weakest group. In the Roadster, the battery had 11 sheets, so that basically functioned as a semi-independent unit (although there were 9 bricks per sheet, each with 69 cells).

From discussions elsewhere, service centers for Roadster have done various fixes including cutting out the bad cell, swapping only one sheet, or swapping the whole battery.
Need my roadster geniuses / Please Help Logs/ 1.5 not charging or battery issue?

I think the bigger problem with Model 3 pack is it is not built in a modular way, so removing individual cells, a group, or a bunch of groups is much harder. It seems to be split roughly in 1/4 (4680 look to be even less modular and is just one whole unit).