BMS-029 - Tesla Must Do Better

I am an early adopter of Tesla. I bought my Model S in Feb of 2015, laying out close to 90k for a car – which is something I would have never dreamed of doing previously. But I believed in the mission, I believed in the car – so I traded in my Kia Optima and subjected myself to this grand experiment. This was the days where the masses really didn’t know what Tesla was – I would get stopped in parking lots and get strange looks on the road – and I gave makeshift mini-presentations about how this was the future of transportation.

Fast forward 8 years and 3 months later…. After Supercharging I received an error on my screen that said “maximum battery charge level reduced” and gave the code BMS_029. After 8 years and 85k miles of very happy ownership – dealing with the usual door handle replacements, window regulator breaks, new MCU, new front dash screen etc – I now realized I was faced with something much more serious.

I planned on keeping my car indefinitely. I love the car. I have never loved a car, but I do love this car.

3 months after my battery warranty expired, I have this error that is going to limit me to about 35% charge, and from everything I read online it is basically a battery death sentence. The Tesla equivalent of the “blue screen of death”. I went to the Tesla Service App, and explained the error and a screenshot – and got back a 15k estimate. No phone call, no options, no offer of repair, no diagnostics - just give us 15k and we will fix it.

Thank goodness for the online community. I found a Facebook group dedicated to this, and lots of help at Teslamotorsclub. I am not an engineer. I am simply a normal consumer. I feel like that needs to be said because if not for the amateur Tesla engineers out there, and aftermarket technicians – I feel like there would be zero information about this because Tesla isn’t talking or explaining. They simply text you back an estimate in an app, with one option – pay us or your car is dead – bricked.

So after doing lots of reading online – and talking to several experts – these are the options:

• Error removal through software. There are people out there who will (for about $500), simply remove the error so that you can go back to where you were the day before this dreaded error showed up.
• Pay anywhere from 8k to 9.5K to ReCell or another 3rd party for a remanufactured battery. You will get a battery pack from a car that they previously replaced, and remanufactured for you. Your battery will then be remanufactured and sold to someone else. You will get a battery pack that is dated anywhere from 2012 to 2015 and a 2 year 25k warranty.
• Pay Tesla about 15k for exactly what ReCell does, but get a 4 year 50k warranty.
• Buy a brand new 90KWH battery from Tesla for about 19k, and get a 4 year 50k warranty.

Option 1 seems like the absolute worst option. It seems like this is widely advised against, as this simply removes the error but doesn’t fix the root cause – which could be catastrophic. This part seems obvious. But hiding under the surface is a very big problem for Tesla – and for Tesla owners – the resale market can never be trusted. When I got this error – overnight – my resale value went from 30k to 10k. If I can remove this error, it goes back up to 30k. So it is obvious that there will be lots of unsuspecting buyers who end up with a car that is going to get the error again – or a potential big problem with the battery – either from a dealer who buys it for 10k and removes the error and sells for 30k, or an individual. This seems like a PR disaster for Tesla – and a horrible situation for consumers. It has already happened multiple times.

Option 2 and 3 are very similar – really just warranty differences. But in the end, if you can get a brand new battery for 4k more, and you plan on keeping the car for a long time, ReCell and Tesla need to do a better job of educating the average consumer (like me) that a reman battery with 8-10 year old cells has a value proposition vs a brand new battery. I fully support ReCell and their mission, because they are doing what Tesla does and beating them on price – and for the right person – it is a great option.

I chose option 4. I hate that I am laying out 19k to basically get back to where I was before the error. But at the same time – with the limited information I have – especially from Tesla – and very limited options – it is the best decision for me. My car is at Tesla right now sitting waiting for the work to be done.

Tesla needs to do a much better job addressing this, and develop a program that has better education and options. Are they trying to get the early cars off the road? Are they trying to get the unlimited supercharging cars off the road? They are getting my battery as part of the 19k repair – and they will remanufacture that and sell it to someone else for 15k. How much work and cost goes in to the remanufacturing? What if it is a circuit board or a few cells or even a module on my battery – that costs them close to nothing in comparison to the 15k they will flip it for – is that fair that I pay 19k on a car that is only worth 30k, and they ALSO get my battery?

Tin foil hat time…. I don’t necessarily believe any of the following to be true – but as Elon likes to say on Twitter – “I am just asking the questions”. What if there was a company that could press a button and send an error to a car fresh out of warranty, and essentially brick it knowing that they then would charge between 15k and 19k to replace it, and in return get a battery that they will sell to the next person they send the error to?

It seems a lot of cars are getting this error just after 8 years. Tesla – isn’t it in your best interest to be more transparent about issues, education, and options? Do you not care that the people this is happening to are the same people who in part built the company to what it is today? I have probably sold 20 people over the years on buying cars, and I have bought a MY. I am not suggesting Tesla owes us anything – but it just seems like a smart business decision to better handle this.

There are lawsuits already out there. Who knows. One persons opinion… This experience has seriously diminished my faith and experience in Tesla. I am biting the bullet – spending 19k on a car that will only be worth 30k when done – but I will always wonder if the BMS_029 error was just a software glitch, a $50 circuit board, a real problem that just happened to occur at 8 years and 3 months – or something much more sinister.

Come on Tesla, you can and need to do better.

"2014 Tesla Model S" by harry_nl is licensed under CC BY-SA 2.0.
Image added for Blog Feed thumbnail

 

[Mhoepfin]

2015 85D here with 85k miles and a march 2015 production date. Gonna keep driving it and hope for the best that I’m in a VIN with one of the improved battery designs that has some longevity. So far I’ve got minimal degradation. If push came to shove and it crapped out I wouldn’t hesitate to put a 90 pack in and keep my FUSC and drive a few hundred thousand miles more. My car is perfect in every way to me.

 

[Werecow]

They have. They learned from the failures of the old packs and have made design changes so that future packs don't suffer the same failures. (It sounds like most of the failures are for pre-2016 packs, and that 2016+ packs should be much more reliable.)

I don't think so. But you can send a data request to Tesla and they will send you a copy of all of your service records, and a lot more, in a ZIP file, and you could pass that, or part of it, on to the new owner if you wanted to.

What you're failing to mention is that Tesla will not tell you anything about a used car prior to owning it. Has it had a pack replacement, does it have any underlying issues that were covered up such as the hack or even does it have free supercharging still. If Tesla were being honest they'd report repair information to Carfax so potential buyers would know if there was a history of problems with a particular car. But they don't and it isn't a privacy issue like they claim.

 

[Crutonius]

I don't think anyone seriously believes it's really a privacy issue. That's just the excuse they use. I think most people probably assume it's to conceal engineering defects.

 

[gt2690b]

I don't think anyone seriously believes it's really a privacy issue. That's just the excuse they use. I think most people probably assume it's to conceal engineering defects.

I sold my 2012 P90 and gave the new owner my zip file of service records and the zip of service records the previous owner gave me so he has all of them (and there were manny) .. it just seems like the logical thing to do if you're about to sell it

Also my Y LR is pushing 50k miles and has never been back to the shop *knock on wood* so it would seem things are getting better

 

[GammaDelta]

This is a very interesting thread. I am also curious on the "an ounce of prevention is worth a pound of cure" front - what is the way to stave off battery replacement as long as possible?

In just this thread you see OP having a very unfortunate and frustrating timing on battery failure (3 mo past warranty), but and also @Gumball mentioning

About warranty, I had this error exact 4 months before my warranty expired on our 2014 S. So I do not believe in the conspiracy theories about Tesla pushing this alert.

My warranty is coming up at the end of this year (Dec 2015) and I plan to keep the S for a long time. I have minimal degradation. But I have entertained the idea of supercharging the hell out of it until the end of the year and see what happens to speed up the chance of an error, but have not done this as I may be left with a battery with higher degradation.

What is the best way to keep our batteries in top-notch condition for as long as possible? Basically "slow" (wall charger 5-40amp) charge up to 80% and use only to ~20%. Rinse and repeat with a sprinkle of supercharging when needed? Seems like OP's error occurred right after supercharging.

 

[gt2690b]

This is a very interesting thread. I am also curious on the "an ounce of prevention is worth a pound of cure" front - what is the way to stave off battery replacement as long as possible?

In just this thread you see OP having a very unfortunate and frustrating timing on battery failure (3 mo past warranty), but and also @Gumball mentioning


My warranty is coming up at the end of this year (Dec 2015) and I plan to keep the S for a long time. I have minimal degradation. But I have entertained the idea of supercharging the hell out of it until the end of the year and see what happens to speed up the chance of an error, but have not done this as I may be left with a battery with higher degradation.

What is the best way to keep our batteries in top-notch condition for as long as possible? Basically "slow" (wall charger 5-40amp) charge up to 80% and use only to ~20%. Rinse and repeat with a sprinkle of supercharging when needed? Seems like OP's error occurred right after supercharging.

There's a post here

Best way to charge to prevent battery degradation?

I've read this too... there are graphs posted somewhere on these forums of SoC studies that show higher degradation right around the 58% mark (oddly specific). I believe this is the graph you're referring to: It shows the calendar aging of batteries at different temperatures in the first 10...

teslamotorsclub.com

That discusses 58% is a plateau for calendar ageing but your basically past that threshold at this point.. I'd still stick with low soc and low depths of discharge as much as reasonable for you for longevity

 

[Crutonius]

This is a very interesting thread. I am also curious on the "an ounce of prevention is worth a pound of cure" front - what is the way to stave off battery replacement as long as possible?

In just this thread you see OP having a very unfortunate and frustrating timing on battery failure (3 mo past warranty), but and also @Gumball mentioning


My warranty is coming up at the end of this year (Dec 2015) and I plan to keep the S for a long time. I have minimal degradation. But I have entertained the idea of supercharging the hell out of it until the end of the year and see what happens to speed up the chance of an error, but have not done this as I may be left with a battery with higher degradation.

What is the best way to keep our batteries in top-notch condition for as long as possible? Basically "slow" (wall charger 5-40amp) charge up to 80% and use only to ~20%. Rinse and repeat with a sprinkle of supercharging when needed? Seems like OP's error occurred right after supercharging.

These are good rules to go by. The problem is that degradation and battery failure are separate events. Slowing degradation doesn't avoid an impending failure.

 

[MP3Mike]

What is the best way to keep our batteries in top-notch condition for as long as possible?

I think the best thing you could do would be a physical inspection to make sure that none of the know water ingress locations are in bad shape. Of course, that pretty much requires removing the battery. I think from what @wk057 has said that a December 2015 vehicle likely has the AC drain line extended so that it doesn't empty on top of the battery, but that is one thing that could be checked without removing the battery. (Though the damage is likely already well on its way by now if it isn't.)

 

[kirkusss]

My car has the drain for the AC extended and the top cover was still rusted. The cover was replaced by Tesla 4 days before the end of the warranty, no water was found inside.

 

[Cheese Guy]

This is a very interesting thread. I am also curious on the "an ounce of prevention is worth a pound of cure" front - what is the way to stave off battery replacement as long as possible?

In just this thread you see OP having a very unfortunate and frustrating timing on battery failure (3 mo past warranty), but and also @Gumball mentioning


My warranty is coming up at the end of this year (Dec 2015) and I plan to keep the S for a long time. I have minimal degradation. But I have entertained the idea of supercharging the hell out of it until the end of the year and see what happens to speed up the chance of an error, but have not done this as I may be left with a battery with higher degradation.

What is the best way to keep our batteries in top-notch condition for as long as possible? Basically "slow" (wall charger 5-40amp) charge up to 80% and use only to ~20%. Rinse and repeat with a sprinkle of supercharging when needed? Seems like OP's error occurred right after supercharging.

20-80 seems to work very well for me. Charging daily to 80% vs 90% the degradation reduction is very noticeable. I actually don't need the entire 80% for my daily commute so have been changing to 70%. I get back home right at 20%.

 

[ucmndd]

Charging daily to 80% vs 90% the degradation reduction is very noticeable.

No, it’s really not.

 

[JVL]

How do I read that graph? Thanks in advance.

 

[Crutonius]

Yeah. I think you might have picked the wrong graph there. It kind of looks like a chart that demonstrates loss of charge based on ambient temperature.

 

[ks1972]

They have. They learned from the failures of the old packs and have made design changes so that future packs don't suffer the same failures. (It sounds like most of the failures are for pre-2016 packs, and that 2016+ packs should be much more reliable.)

Good for future owners, still doesn't do anything for owners of cars with pre-2016 batteries.

What's interesting is all of warranty works on my 2 cars last 4 years have always said "goodwill" on the invoice and not warranty work, I guess Tesla doesn't want to acknowledge their cars are in the shop for multiple warranty works.

In this case, Tesla could potentially show some real goodwill to their customers and proactively diagnose these batteries and offer fixes. After all, they have learned that these batteries have design/other flaws. I just wonder how this didn't end up being a recall, guess some federal agency should look into it.

 

[ucmndd]

Yeah. I think you might have picked the wrong graph there. It kind of looks like a chart that demonstrates loss of charge based on ambient temperature.

Ambient temperature AND state of charge over different durations of time.

The main takeaway is that the difference in retained capacity when stored at 80% vs 90% is almost completely negligible until you get to very hot temps.

 

[ucmndd]

How do I read that graph? Thanks in advance.

Each line represents a temperature and duration of storage in months.

X axis is state of charge the batteries were stored at.

Y axis is the amount of degradation experienced after storage.

So looking at the points plotted on each line for 80% storage and 90% storage, we can say pretty definitively that “charging daily to 80% vs 90% the degradation reduction is very noticeable” is not at all true based on this data, at least until you get to very warm storage temps.

BTW - this graph and conclusions are cribbed from @AAKEE ’s posts and research on this topic in other threads.

 

[MP3Mike]

I just wonder how this didn't end up being a recall, guess some federal agency should look into it.

Recalls are for safety issues, and I doubt this would be considered a safety issue. (As long as you don't mess with the BMS, there is very little, if any, risk of fire.) And with the more recent firmware versions it doesn't even leave you stranded, it just limits how much you can charge the battery, while letting you know to get your car repaired. (There was no recall for all of the ICE vehicles where there was a design flaw in the radiator that caused it to destroy the transmission by intermixing the fluids. They fixed the ones that failed in warranty, and let the out of warranty customers eat the $$$$ repair bills.)

And technically the warranty doesn't cover design defects. (As has been determined by courts in some law suits, as they are written they cover defects in materials and workmanship, not design. Which seems silly, since they obviously cover failures that are because of a design issue when it is in the warranty period, but I guess they don't have to.)

 

[ucmndd]

I just wonder how this didn't end up being a recall, guess some federal agency should look into it.

Recalls are for safety issues. A battery that proactively identifies a potential safety issue and neutralizes it is not a safety issue.

 

[NV Ray]

One current challenge for affected owners is Tesla's pack replacement cost which hopefully will be mitigated in the future.

Tesla's current rate of $15,000 for reman pack to $20,000 for new pack on a current value $25,000-$30,000 2012-14 Model S would probably total the car if similar accident repair costs were handled by an insurance company.

This topic would likely be a mute point if Tesla charged say, $5000, for a replacement pack.

 

[ks1972]

There are a couple of right-to-repair Tesla class action lawsuits in federal courts, hopefully, one of them have some positive outcome for owners