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Time for a new HV Battery

@NV Ray I'm super interested in the Supercharger charging speeds with your new pack. If you'd be so kind (along with anyone else!) as to share your experiences (when you have some decent data under your belt) I'd appreciate it.
Kinda new to this. What data are you interested in?
Hey hey . I made your list. 🤣
Any more specific details?
 
Yes, this is totally sus. Tesla is not the only electric car company with battery packs that are 8+ years old -- not to mention hybrids with much older battery packs. But Teslas are the only vehicles that are crippled unless the battery pack is replaced for $15k - $20k ... and these issues conveniently happen after the warranty period (and after an OTA update).
Wow are you implying that they f your battery up with an ota update once warranty is gone?
 

ucmndd

Well-Known Member
Mar 10, 2016
10,145
19,904
California
Wow are you implying that they f your battery up with an ota update once warranty is gone?
This guy is a conspiracy theorist with a bone to pick. He thinks Tesla killed his HV battery with a software update despite any evidence and is out to make a point. There’s nothing of value to uncover in this old thread.
 

Recell

Member
Global Vendor
May 22, 2022
87
184
Austin
We can safely report that to the one, every reported battery error we’ve had come through our facilities has been backed up by some kind of malfunction or failure of one or more physical components located inside the pack in question.

with 500+ datapoints available to our techs with our cloud-based software tools, we can quickly pinpoint the exact issue at hand, often within minutes - whether it’s a failed Battery Monitoring Board (BMB), a loose voltage sensor, an internal pack isolation error, an issue with the contactors, or an outright failure of a module brick itself.

and yes, while there’s the occasional headscratcher that prompts a deeper dive into the data, in the vast majority of cases, it quickly becomes obvious what the issue is. (hint: about 85% of the time it’s an outright brick failure, and another 10% or so it’s some combination of a board failure or loose voltage sensor)
 
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We can safely report that to the one, every reported battery error we’ve had come through our facilities has been backed up by some kind of malfunction or failure of one or more physical components located inside the pack in question.

with 500+ datapoints available to our techs with our cloud-based software tools, we can quickly pinpoint the exact issue at hand, often within minutes - whether it’s a failed Battery Monitoring Board (BMB), a loose voltage sensor, an internal pack isolation error, an issue with the contactors, or an outright failure of a module brick itself.

and yes, while there’s the occasional headscratcher that prompts a deeper dive into the data, in the vast majority of cases, it quickly becomes obvious what the issue is. (hint: about 85% of the time it’s an outright brick failure, and another 10% or so it’s some combination of a board failure or loose voltage sensor

Are you finding any coorelation to time, miles, recent OTA update...?
 
(hint: about 85% of the time it’s an outright brick failure, and another 10% or so it’s some combination of a board failure or loose voltage sensor)

Based on this statistic, then the main scalable solution is just to remove the failed module and configure the car the lower range? Which I believe is your RC210+ offering?

Model S 85 (recell-ev.com)
 

Recell

Member
Global Vendor
May 22, 2022
87
184
Austin
Are you finding any coorelation to time, miles, recent OTA update...?

as noted above, the clearest correlation is between a component failure and the generation of an error code - BMS_u029 being the most common.

to the point that replacing a failed board or removing a failed brick returns capacity variance across the entire pack to within 1 or 2 standard deviations

given the strength of that correlation, we haven’t spent any research cycles applied to the OTA issue that some have speculated about.
 
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Recell

Member
Global Vendor
May 22, 2022
87
184
Austin
Based on this statistic, then the main scalable solution is just to remove the failed module and configure the car the lower range? Which I believe is your RC210+ offering?

Model S 85 (recell-ev.com)

yes.

now… we’ll fine tune that slightly to say that removal of a single brick out of the 96 in a typical pack, is usually more than sufficient to return capacity variance across the entire pack to within 1 or 2 standard deviations.

this is basically the same issue you have with a string of Christmas lights - one goes down, they all go down.

and yes, highly scalable. with a steady of inventory of packs always at the ready, our current turnaround time is same day/next day with a 1-2 week backlog in our customer deliveries. that’s a game changer. 👍
 
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yes.

now… we’ll fine tune that slightly to say that removal of a single brick out of the 96 in a typical pack, is usually more than sufficient to return capacity variance across the entire pack to within 1 or 2 standard deviations.

this is basically the same issue you have with a string of Christmas lights - one goes down, they all go down.

and yes, highly scalable. with a steady of inventory of packs always at the ready, our current turnaround time is same day/next day with a 1-2 week backlog in our customer deliveries. that’s a game changer. 👍

Actually one more relevant question. Any idea what % of the brick death packs are due to moisture ingress vs cell failure without external visible damage?

Asking because moisture ingress seems pretty significant on these packs given where its located and electricity (HV even) and water don't mix. If moisture is the killer of bricks, the perhaps a reconditioning service to clean up moisture ingress damage + reseal before brick failure might provide longevity?
 
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Actually one more relevant question. Any idea what % of the brick death packs are due to moisture ingress vs cell failure without external visible damage?

Asking because moisture ingress seems pretty significant on these packs given where its located and electricity (HV even) and water don't mix. If moisture is the killer of bricks, the perhaps a reconditioning service to clean up moisture ingress damage + reseal before brick failure might provide longevity?
@wk057 has opined on this before …
 

Rocky_H

Well-Known Member
Feb 19, 2015
8,757
11,432
Boise, ID
If moisture is the killer of bricks, the perhaps a reconditioning service to clean up moisture ingress damage + reseal before brick failure might provide longevity?
@wk057 has opined on this before …
Yes, here is the thread describing this procedure.

 
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Yes, here is the thread describing this procedure.


Yes, am familiar with this thread.

Like to gather some metrics for stats. @Recell says 85% failure pack = dead brick. Like to know what % in this 85% is water ingress vs battery internal chemical failure. Probably not so easy to determine.

Maybe water ingress cause excessive discharge killing the cell without visible damage on the cell? Maybe statistical failure of 7k Lithium Ion cells going through all internal chemical and micro-mechanical failure mechanisms (would need advanced inspection equipment to determine)

Not sure can be answered easily. These are 2 separate failure paths. Would be good to gain insight on relative longevity of each.

Also need to factor in failure mechanism data while under 8 year warranty is all buried inside Tesla. We do hear under warranty failures but obviously not nearly as noisy as when owners has to pay $$$. So the pack naturally appears reliable for 8 years but not soon after :)

I suppose regardless of difficulty to untangle multiple failure factors + hidden data. Water ingress issue is popping up for after warranty period cars. Lets say we do post warranty battery pack recon/update weak parts/reseal, how soon will cell internal failure appear after? Maybe insufficient data to answer this question...
 
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Recell

Member
Global Vendor
May 22, 2022
87
184
Austin
we categorize water/moisture ingress as water/moisture ingress. the 85% we cited above does not include packs with either visible signs of water ingress or onboard detection of moisture by the BMS. the overriding factor here is calendar age, mileage, and chemical deterioration/dendrite growth. in short, life.

some portion of the board and voltage sensor failures are either moisture related or manufacturing defects, or both; and some portion of the 5% 'other' remaining in the pie is outright water ingress. As we've said before, water/moisture ingress isn't zero, but far outweighed by the aging factors noted above.
 
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we categorize water/moisture ingress as water/moisture ingress. the 85% we cited above does not include packs with either visible signs of water ingress or onboard detection of moisture by the BMS. the overriding factor here is calendar age, mileage, and chemical deterioration/dendrite growth. in short, life.

some portion of the board and voltage sensor failures are either moisture related or manufacturing defects, or both; and some portion of the 5% 'other' remaining in the pie is outright water ingress. As we've said before, water/moisture ingress isn't zero, but far outweighed by the aging factors noted above.

Thanks! Great data. So the basic Lithium Ion (LiOn) chemical/dendrite failure does dominate the pack failure mechanism.

So the obvious question is... If able to repair through cutting down capacity (removing the failed section while preserving balancing), why isn't the next cell in the remaining pack around the corner from failure? Or is the first failure really an ultra short life outlier from remaining cells? Sorry for so many questions... just trying to understand the multiple pack failure modes and which dominates. Your stats are really illuminating.

For those wondering how LiOn batteries fail internally, a good summary here

Battery Degradation Scientifically Explained - EV Battery Tech Explained - YouTube

Specific failure mechanisms might be LiOn but have commonality with all rechargeable chemistry since its invention 100 years ago. For example

- Attractive forces between anode and cathode sheets packed close together really want to build a bridge that triggers a short when completed
- Parasitic loss during charge and discharge reactions.
 

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