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

 

[father_of_6]

Only for vehicles designed to do that.

Exactly.

As I said before: you can keep dreaming. It might be possible in the future, but I think only if some completely new type of battery cell/formulation was invented. Technically someone could probably design a pack to do that, but would you pay ~$7-10k extra for that? And with that would come a lot more complexity, which would add additional new failure modes. So you would likely have to repair the pack much more often.

Doesn't it seem odd to you that none of the companies making EVs have designed a pack to withstand a single cell failure? (I'm sure they have all researched it, and likely determined that it wasn't worth the extra effort/expensive and additional failure modes.)

I will keep dreaming . It doesn't seem odd that no one has tackled the single cell failure problem. Tesla is the only real EV player, and they've been busy just trying to plant roots and establish themselves in an industry where that has been virtually impossible for many decades.

Legacy auto was asleep at the wheel and only recently realized that they had to convert to EVs, so they're all too busy just trying to to ensure survival - long term issues like pack failure from a single cell are nowhere on their roadmap.

--

Still... when the dust settles and ICE is no more, spending $15k on 7,000ish cells plus labor just because of 1 failed cell is a problem that must be solved. I believe it can be done without adding significant additional costs, complexity, and points of failure. Someone much smarter than me will figure it out.

 

[gt2690b]

That sort of supports my point. A Google search tells me that replacing the water pump in a prius is about $900. The oil burning problem could potentially be something you might as well get a new engine to fix but it's also something you can live with. It's not going to leave you stranded.

Will an S reach 220k miles with one minor fix and one persistent annoyance? I wish I had the data to say for sure but I doubt it.

Ain't nobody putting a new engine in a Prius with over 200k miles

 

[ucmndd]

Will an S reach 220k miles with one minor fix and one persistent annoyance?

I’m at 170k and counting, I’ll let you know. So far so good.

 

[father_of_6]

Tesla is the only real EV player, and they've been busy just trying to plant roots and establish themselves

Just to elaborate... Tesla made the Roadster - a very expensive car that very few people would want or could afford, and used the profits and experience to build the Model S... rinse and repeat and we have the Model 3.

Their trajectory is the bottom. They're aiming for mass market. The "Model 2" and whatever comes after it are going to have to compete with China, who for the first time are going to actually successfully enter the American market.

The idea that the $18k 2038 NIO hatchback might need a $7k battery replacement after 8 years is preposterous. We can't keep throwing the baby out with the bathwater. It might be acceptable for now because EVs are premium priced and mostly have been sold to early adopters, but it's no good for long term general public, their wallets, and their sense of value.

In many conversations with non-EV drivers, a common question I've heard is... "Don't the batteries cost like $10,000?". If they knew the answer was more like $15-20k, they'd mentally remove any future possibility of switching away from ICE. That perception has to die. The answer needs to become... "Maybe replacing the whole battery, but that never happens - they just disconnect bad cells. Your battery will last 20 years." Essentially buying an EV feels like a massive financial gamble that's only available for the wealthy. ICE vehicles don't have $20k failures.

 

[ucmndd]

We can't keep throwing the baby out with the bathwater.

Cost will almost certainly come down in the future as additional infrastructure is put into service and economies of scale are realized. But even now, this isn't what happens. Battery minerals can be almost infinitely recycled into new cells - this is what's going to ultimately propel the industry forward.

The economics still pan out and provide a net positive to the consumer and the environment. Would you rather spend $5-8k on a new battery in 8-10 years, or a much greater amount in fueling costs over the life of the vehicle? I know my answer. Trying to mimic the exact economic model and value proposition of ICE cars is not a logical path forward. Chemical and physical realities of current battery technology will make your proposed panacea infeasible for many many years to come.

 

[Crutonius]

Just to elaborate... Tesla made the Roadster - a very expensive car that very few people would want or could afford, and used the profits and experience to build the Model S... rinse and repeat and we have the Model 3.

Their trajectory is the bottom. They're aiming for mass market. The "Model 2" and whatever comes after it are going to have to compete with China, who for the first time are going to actually successfully enter the American market.

The idea that the $18k 2038 NIO hatchback might need a $7k battery replacement after 8 years is preposterous. We can't keep throwing the baby out with the bathwater. It might be acceptable for now because EVs are premium priced and mostly have been sold to early adopters, but it's no good for long term general public, their wallets, and their sense of value.

In many conversations with non-EV drivers, a common question I've heard is... "Don't the batteries cost like $10,000?". If they knew the answer was more like $15-20k, they'd mentally remove any future possibility of switching away from ICE. That perception has to die. The answer needs to become... "Maybe replacing the whole battery, but that never happens - they just disconnect bad cells. Your battery will last 20 years." Essentially buying an EV feels like a massive financial gamble that's only available for the wealthy. ICE vehicles don't have $20k failures.

I doubt it'll be 5-7k to fix. Elon... says a lot of things. I'll believe it when I see it. I suspect the actual cost will be higher.

Fundamentally I think the problem is that Tesla's battery management system is just inadequate. It's made to handle a matching set of virgin cells where everyone of them peacefully degrades in unison and not one ever goes rogue. Luck, I think is the word for that. Tesla battery packs are designed for the very lucky. One should determine how generally unlucky they are before buying an EV.

 

[ucmndd]

Fundamentally I think the problem is that Tesla's battery management system is just inadequate.

By essentially all informed accounts, Tesla's BMS is a work of art and the best in the business by a mile.

Making 6,000 to 8,000 of _anything_ behave like a single thing, including aging gracefully and managing emerging safety concerns is a super hard problem. Tesla's batteries appear to be quite reliable by any measure, early production teething problems notwithstanding.

 

[gt2690b]

I doubt it'll be 5-7k to fix. Elon... says a lot of things. I'll believe it when I see it. I suspect the actual cost will be higher.

Fundamentally I think the problem is that Tesla's battery management system is just inadequate. It's made to handle a matching set of virgin cells where everyone of them peacefully degrades in unison and not one ever goes rogue. Luck, I think is the word for that. Tesla battery packs are designed for the very lucky. One should determine how generally unlucky they are before buying an EV.

7k battery 4k labor.. not too much of a stretch.. still cheaper than 200k miles of gas

 

[cduzz]

There are other sayings, like: "Once Is Chance, Twice is Coincidence, Third Time's A Pattern." It is incredibly coincidental that these packs miraculously "age" right after 8 yrs / warranty expires.

The other thing that may surface in a lawsuit (especially in Europe) is how private customer videos (naked guy in garage, child on bike hit by Tesla car, etc.) were distributed internally.

I don't think there's anything nefarious going on -- large organizations typically don't crime without internal record keeping documenting the crime, and that's trivially discovered via legal processes. There's almost certainly a chain of evidence along the lines of "engineering report XYZ reporting that after inspecting 20 failed 2013/2014 packs, we can monitor ABC environmental feature and discover which packs are likely to fail before they're a hazard" and then there's an internal ticket somewhere to implement that monitoring, and then there's some record keeping to identify how reliably that new monitoring identified which failed packs.

It may be that there's some tinfoil hat alignment between "let's get these old cars off the road" and "let's keep these old cars from catching fire and killing people while they sleep" but I don't think it's an overt program to try to kill these old cars; I don't think it's a big enough number for tesla to care at all.

The poor internal housekeeping is probably the normal record keeping practice at large organizations and will hopefully be cleaned up as a result of a couple of lawsuits from affected parties.

 

[Crutonius]

By essentially all informed accounts, Tesla's BMS is a work of art and the best in the business by a mile.

Making 6,000 to 8,000 of _anything_ behave like a single thing, including aging gracefully and managing emerging safety concerns is a super hard problem. Tesla's batteries appear to be quite reliable by any measure, early production teething problems notwithstanding.

And yet a single cell failure is enough to completely incapacitate it. Maybe it is the best BMS in any EV. But when it can't workaround a single failure that's like saying it's the prettiest waitress at Dennys.

 

[ucmndd]

And yet a single cell failure is enough to completely incapacitate it. Maybe it is the best BMS in any EV. But when it can't workaround a single failure that's like saying it's the prettiest waitress at Dennys.

Sounds like you need to stick with ICE. Enjoy while you can.

 

[Crutonius]

Sounds like you need to stick with ICE. Enjoy while you can.

I think I need to update my sig. Apologies since this wasn't clear. I'm in the same boat as the rest of you. I drive a Model S. My intention is not to attack Tesla. As the OP said, I just want them to do better. And excusing their flaws is counterproductive towards those ends.

 

[cduzz]

As you say the first option isn't viable, and can end very badly, and has recently been reported on Twitter.


You can keep the old pack if you want to. (Last I heard Tesla charged something like $15k as a core charge if you kept the old pack.)

If the failure is a bad cell, or module, Tesla can't remanufacture it and just sends the entire pack to be recycled back into the base materials to make new cells. (You can't replace a bad cell, or module, and have the pack continue to function properly.) If it is just a bad circuit board or a few other minor things they can normally remanufacture the pack and then resell it.

How much of a core charge would @Recell or @wk057 charge if you kept your old pack? (Or will they even offer their service if you don't provide a core?)

In the scenario where a single module in a 100D pack has failed, can't they pull that (and another) module from the pack and call it a "refurbished 90" pack?

What I've read, otherwise, there's no fixing a pack by swapping modules around between packs or by snipping wires; both of which may keep a pack working for a bit more time but not actually fix it.

 

[MP3Mike]

In the scenario where a single module in a 100D pack has failed, can't they pull that (and another) module from the pack and call it a "refurbished 90" pack?

Yes, it can be done, but Tesla doesn't offer it as a service. (At least that I have seen.)

 

[ucmndd]

And excusing their flaws is counterproductive towards those ends.

I'm all in on calling out Tesla on their flaws.

I have difficulty attributing the inherent chemical and physical "flaws" of lithium ion cells in 2023 to Tesla or any other vehicle manufacturer. That's nonsensical and doesn't add anything particularly useful to the conversation.

 

[NV Ray]

Oh what joy it would be if a Quality Assurance Tesla employee is monitoring this thread Fascinating conversation and great dialogue.

@JVL great OP. Let us know how your new $20k pack from Tesla goes today. You'll love the new pack.

 

[JVL]

Oh what joy it would be if a Quality Assurance Tesla employee is monitoring this thread Fascinating conversation and great dialogue.

@JVL great OP. Let us know how your new $20k pack from Tesla goes today. You'll love the new pack.

I will update the thread. But it won't be today.

As we all know, part of the fun of the Tesla service experience is dropping off your car with a 2 week estimate to do a 4 hour job. It has been there a week, and I dont expect it back for another week.

 

[NV Ray]

I will update the thread. But it won't be today.

As we all know, part of the fun of the Tesla service experience is dropping off your car with a 2 week estimate to do a 4 hour job. It has been there a week, and I dont expect it back for another week.

Did they give you a free loaner?

 

[Jayskywalker21]

I will update the thread. But it won't be today.

As we all know, part of the fun of the Tesla service experience is dropping off your car with a 2 week estimate to do a 4 hour job. It has been there a week, and I dont expect it back for another week.

That's so crazy my estimate to get the car back is on June 8th and it was dropped off on the 1st. Getting a new HV battery. They Initially said June 16th... Guessing they had a pack already and it's being sent out quickly.

 

[Crutonius]

I'm all in on calling out Tesla on their flaws.

I have difficulty attributing the inherent chemical and physical "flaws" of lithium ion cells in 2023 to Tesla or any other vehicle manufacturer. That's nonsensical and doesn't add anything particularly useful to the conversation.

Okay I think I see where you're coming from. Since Tesla didn't make the lithium ion cells then it's not their problem. And therefore it's not our place to pressure them to mitigate any cell failures. And really our beef is with Panasonic. So we should be writing angry letters to them for making batteries that eventually fail.

It's an interesting perspective. I'm not so sure I agree with it.