My battery warranty expired last May this year for my 2015 Model S 85D with just 65K miles. December I got the BMS029 alert! Do you think this is coincidence or planned obsolescence?
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Starting to see 2015s with BMS_u029 and 018
- Thread starter NV Ray
- Start date
While I agree with you, have you had to pay for a replacement pack?
No, but I don't understand how that is relevant. Tesla has stated that the early packs actually lasted longer than they expected them to, and that the failures were not what they expected. (Cells lasted longer than they thought, but things like vibration and moisture ingress caused problems they weren't expecting.)
I believe Tesla made 3 known improvements that likely had an effect. But still other failure modes exists. Tesla deploys revision changes mid year so probably can't just go by year alone. Nor do they publish a table on when these revisions are deployed.
1. Fuse Cover moved to Bottom (2016+?)
Fuse Cover on top side of battery gets attacked from windshield water runoff. Salted road regions and cars parked outside in high rain fall regions see much failure from this. Fuse cover on model X (released in 2015) moved to facing the ground so gravity + sitting water don't just eat at the seal / rust the metal cover. Model S parts catalog shows >= April 2016 manufactured cars likely have similar bottom facing fuse cover. However, it isn't so clear from Tesla repair directions which battery version got this update. Maybe one of the pack revisions indicate this change. I don't know.
Should be easy to see if have bottom facing fuse cover. Ground facing just behind the part+serial number sticker.
2. Front hump silicone valve air equalizer removed (2020-21+?)
I have seen pictures of newer packs (2020 or 2021) without this valve. This valve is likely the failure on @mr_hyde 2015 pack as moist air (and/or standing water from windshield runoff) entered when valve opened to equalize air pressure. Moisture condensation inside the pack than attacks frontal pack electronics boards and other areas.
3. AC drain moved forward (2014+?)
AC drain moved from back of the frontal battery hump to front of the hump. Back of the hump is like a moisture trap and attacks the hump seam sealants. Front of the hump still dumps AC drain water near the frontal seam and with wind blowing backwards while the car is moving forward. It still attacks the seam metal and sealant on front of the hump but probably a lot less than the rear hump drain dump. A complete remedy should router the drain to clear exit point below the car and doesn't blow back up into the car.
Those with packs from after mid 2016 might fair better in moisture + salted road regions with #1 improvements. But of course #2 issue is still there as well as other failure modes.
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I think there are other improvements but its uncertain they had much of an impact
One prominent "improvement" could just be social media PR as the Tesla hired battery consultant (Canadian professor with battery testing lab) did many talks. This professor pioneered rapid testing of battery cell chemistry longevity. The theory is this allows faster chemistry improvement trials. This naturally gets picked up by tech social media youtubers which then lead people to believe rapid improvements like silicon chips Moore's law.
I have seen 2 Model 3 pack repair efforts. Both were shorted cells. Since rechargeable battery cell shorts over time+use is unavoidable. It isn't clear if this failure mode has been improved. Furthermore, this failure mode can occur with micron scale manufacturing defect.
1. Fuse Cover moved to Bottom (2016+?)
Fuse Cover on top side of battery gets attacked from windshield water runoff. Salted road regions and cars parked outside in high rain fall regions see much failure from this. Fuse cover on model X (released in 2015) moved to facing the ground so gravity + sitting water don't just eat at the seal / rust the metal cover. Model S parts catalog shows >= April 2016 manufactured cars likely have similar bottom facing fuse cover. However, it isn't so clear from Tesla repair directions which battery version got this update. Maybe one of the pack revisions indicate this change. I don't know.
Should be easy to see if have bottom facing fuse cover. Ground facing just behind the part+serial number sticker.
2. Front hump silicone valve air equalizer removed (2020-21+?)
I have seen pictures of newer packs (2020 or 2021) without this valve. This valve is likely the failure on @mr_hyde 2015 pack as moist air (and/or standing water from windshield runoff) entered when valve opened to equalize air pressure. Moisture condensation inside the pack than attacks frontal pack electronics boards and other areas.
3. AC drain moved forward (2014+?)
AC drain moved from back of the frontal battery hump to front of the hump. Back of the hump is like a moisture trap and attacks the hump seam sealants. Front of the hump still dumps AC drain water near the frontal seam and with wind blowing backwards while the car is moving forward. It still attacks the seam metal and sealant on front of the hump but probably a lot less than the rear hump drain dump. A complete remedy should router the drain to clear exit point below the car and doesn't blow back up into the car.
Those with packs from after mid 2016 might fair better in moisture + salted road regions with #1 improvements. But of course #2 issue is still there as well as other failure modes.
===
I think there are other improvements but its uncertain they had much of an impact
One prominent "improvement" could just be social media PR as the Tesla hired battery consultant (Canadian professor with battery testing lab) did many talks. This professor pioneered rapid testing of battery cell chemistry longevity. The theory is this allows faster chemistry improvement trials. This naturally gets picked up by tech social media youtubers which then lead people to believe rapid improvements like silicon chips Moore's law.
I have seen 2 Model 3 pack repair efforts. Both were shorted cells. Since rechargeable battery cell shorts over time+use is unavoidable. It isn't clear if this failure mode has been improved. Furthermore, this failure mode can occur with micron scale manufacturing defect.
It is unclear if my valve is a 'failure' in that it malfunctioned or if the fact that the pack breathes at the front and all of my corrosion was in the front is more of a design flaw. Regardless, I'm certain the correlation is relevant.
For the record, my pack had a failed capacitor on BMB 8 but also had corrosion on #9 and three of the four forward-most modules with everything behind them showing no sign of condensation or corrosion. The pack was completely dry with no liquid water but there were visible condensation bridges between the plastic shield covers on the modules and some of the failed/failing caps.
It is clear to me that these packs need some kind of moisture and humidity mitigating process. I'm going to play around with changeable desiccant cartridges using the umbrella valve holes. These should be able to push up into the module bay without making contact with anything and absorb moisture. Unfortunately, they will be at the farthest point from the BMBs where they are needed most but there is no room or good way to make a changeable dry pack serviceable in the center of the pack. I'm not sure it will help and certainly don't think it will 'solve' the moisture issue but it shouldn't hurt.
This is a low-tech approach. The better solution would be to design a pack interface that completely seals the pack except for a dried-air loop that uses an evaporator and mechanical drier to condition the air inside the pack. Wouldn't it feel good to have this system running while your battery is heating/cooling and see water dripping out of the condensation drain like the AC does? This retrofit will need to come from the aftermarket, because if Tesla designs it, they will have the condensate drain dropping on top of the battery again...
I'm considering signing myself up since I'm positive our 2013 S85 was affected by the software update back in Summer 2019. Overnight drop in range (256 to 244), power, and significantly longer Supercharging sessions. Never had the battery performance restored or enhanced, 2 years later my range dropped again from 244 to 232. Oddly, I had one magnificent Supercharging session earlier this year when the charge rate peaked at 134kW and held above 100 for quite some time.
Hagens Berman seems like a much better suited law firm with a good track record.
I had not seen this thread before today, but I am glad now that I have decided to trade in my 2015 Model S 70D even though it has only 69,000+ miles. The car has served me well, although not without the usual collection of mechanical failures. My main reason for trading it in is to get a more comfortable car, and in particular an SUV for a seating position that my orthopedist thinks will be helpful to my arthritic back (vs the low seats in my S). But I have also been very mindful of the now-expired 8-year battery warranty.
It is frustrating that it is quite difficult to find solid data on the failure rates of batteries. It seems as if we see anecdotal reports every day of cars whose batteries have just failed, OR contrary reports by people telling how their car has lasted umpteen thousand miles with no battery issues.
My S is not worth much on a trade, but it is essentially in good mechanical shape and seemingly could indeed serve someone well for many years -- IF the battery holds up. I won't know who buys if after I trade it in, but I wish that person well...!
It is frustrating that it is quite difficult to find solid data on the failure rates of batteries. It seems as if we see anecdotal reports every day of cars whose batteries have just failed, OR contrary reports by people telling how their car has lasted umpteen thousand miles with no battery issues.
My S is not worth much on a trade, but it is essentially in good mechanical shape and seemingly could indeed serve someone well for many years -- IF the battery holds up. I won't know who buys if after I trade it in, but I wish that person well...!
aerodyne
2 of 3 EV's - Defect Free!
I had a 2015, and treated it very well, almost never in the wet or parked outdoors overnight.
I sold it and wished the new owner well, but that pack failed a few months later at only 69k miles.
Fortunately, under warranty. Unfortunately, replaced with a reman pack. He is not too confident about longevity.
I wish there were a way to get more data on failure rates.
Best data is at Tesla but nothing revealed. Can try a logical mind experiment : If failure rates are very low, high motivation to publish info to aid sales. If failure rates aren't insignificant and no low cost repair solution, quite natural to not share data.
Alternative method is to do design review which require knowledge of product's construction and the fundamental underlying sciences. This effort can reveal the longevity challenges. Key construction issue is avoiding water + electricity mixing. Key sciences is chemical rechargeable battery cell bridging/shorting with time+use regardless of anode/cathode materials.
Heard a great description from a battery rebuilder once : Tesla get you 8 years on the new battery. Rebuilding get you another 4. Makes a lot of sense. Rebuilds continue to use worn cells and will eventually short. Rebuilding effort can be thought of as repairing the assembly of cells of moisture and mechanical damages.
My goal with my refurbishment is to get the pack to run long enough to have cells start failing. No amount of effort on my part can keep the chemistry from breaking down, but I can, hopefully, keep the BMB boards and physical connections inside the pack viable. If these packs were designed and built well enough that 99%+ made it to the point of chemical failure, the narrative 12 years into this experiment would be that the batteries last forever (they don't, but 12 years in, we would think they do). Unfortunately, there are enough issues with the pack's engineering that we are seeing countless packs fail with 7,104 working, viable cells.
Just wanted to inform that my 2015.10 pack (T15J....) which was mounted in my Model S 70D on October 5 2015 has the fuse box in the bottom. Here in Denmark we call the pack a Version 2.0. So much earlier than 2016+?
Model:
1055893-00-C
Serial: T15J0109835
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