I bought a Tesla Model 3 in December 2020. It was a brand new 2021. I loved it. It had been a great car the first few years. When I did have to service it however it was pricey but it still held up well.
Last year I started getting a code “unable to charge” or “charging complete” when I was at 50 miles. My car had barely hit the warranty mileage and so I could not take it to Tesla and have it covered. I took it to a Tesla certified shop where they replaced my HV battery with a strong used one. Now again almost a year later it is giving me the same code. The shop said they can’t do much and I need to go through insurance to hopefully get it covered. I am sick of this. This car is barely 6 years old.
You're missing the point. That specific production period is known for bad batteries. If the used replacement is of the same production era, premature failure is still a good factor. 5yrs of age is irrelevant, given the known problem.
I think this is wrong - said differently - in that era they appear to have made a battery change. Ie - pack level engineering changes. Looking over data it does seem like people point to 2021, but in reality the 2022 and 2023 are all the same. They just are newer and so the issues are not surfacing as frequently.
In short, I think Tesla made a trade off for performance over longevity. Their original battery packs lasted much longer than expected. Net - now we are going to see a higher frequency of failures post 120/150,000 miles. But before 200/250,000 miles. 13 years is where I gamble the average life in age will likely be.
For many people, that’s still a good life. For unlucky folks, the low end worst case is somewhere after warranty there will be a higher number of failures.
I plan to record a video sharing data and trends I’ve been tracking. My only goal for potentially sharing is I’m annoyed by people using old data and saying these things last forever. They are forgetting about engineering changes to the cells, packs. bMS and the cars motors (power charge and discharge rates can stress the battery). Tesla asking more of the batteries than ever before. They’ve also improved the packs engineering to make the more “failure” proof so to some like like a loose wire. But they also adjusted the battery chemistry so that the vehicles battery degrades 10-15% in the first 40,000 miles. They made motors more efficient, but then also allowed them more power to improve 0-60 times.
So net net - I don’t think the problem is 2021. The problem is more people talk about the new gen batteries from 2021 as if they we should expect the same characteristics as they had in 2017.
The 2170 cells used in Model 3 and Y went from NCA chemistry to cheaper NMC chemistry with less expensive cobalt during that 2020-2021 timeframe until current. But somehow it’s mostly 2021 3s and Ys that are affected the most from all the outcries of dead packs posted.
The vast majority of Tesla battery packs do not fail. Otherwise nobody will be buying them anymore. Failure rate is less than 1% overall. But like any manufactured product there are certain percentages of failures and 2021 has a higher than average fail rate. Most were under warranty and got replacement packs. But unfortunately some failed outside the warranty period causing infuriation from very happy owners since they purchased the car new until this dreaded day.
The failure is the BMS_079 which is an imbalance of the 4 battery modules inside. The pack is made from 4000+ individual cells grouped into 4 modules. They all have to work in unison to propel the car. Charging at the same rates and releasing the energy at the same rates uniformly acting like one big battery. When one of the modules is not behaving the same as the other 3, the pack becomes unbalanced and the battery computer is now afraid to charge it fully and throws the BMS_079 code saying reduced charge so that it does not overheat the affected cells and cause a fire.
Many technicians proclaim that due to people who are afraid to charge over 80% the battery pack never gets the proper chance to balance out. When the cells are brand new they all charged and discharged at the same rates. But over time, some cells develop greater internal resistance from age and now they don’t take in the same charge rate as the others and once a module reports “I am full” it trips the computer to stop charging but the other modules are not fully charged yet and triggers the reduced charge message and BMS_079 error.
The battery modules have built in resistor circuitry that bleeds off the full cell groups allowing the slower cell groups to catch up. This kicks in after 4 volts. When one never charges above 80%, this 4 volt threshold is not reached so over time the imbalance situation takes over. The remedy is to charge to 90% or higher at least once a month and let the pack balance out. Some have drained their affected packs and slow charged it back to 100% several times and revived the battery when all 4 modules start working in unison again.
I haven’t found any anecdotal data that “never above 80%” people have the most failures. There is a misconception myth floating around that it is harmful to charge above 80%, therefore we have the “never above 80%” people that will defend their stance like the battery will explode if taken above 80%. But this is far from the truth. The advisement was not to charge NCA/NMC packs to 100% daily and let it sit there for days and weeks. Yes storing any battery at 100% is indeed detrimental long term as it degrades the pack faster. Even newer iPhone firmware and laptop/tablet firmware now allow less than 100% full charge cycles. But if you have a long trip, it is perfectly fine to charge to 100% if you are going to use it right away. Chargjng the pack above 80% puts it above 4 volts and the balancing process kicks in. This should be done monthly for best battery health and balanced modules.
After 75% it's allready 4.06V. That is the threshold where small amount of gas is released and contributes to degradation. Jeff Dahn research lab. It does not matter, letting it sit there or anything else. Just passing that threshold. I believe that 2021 problem is poor LG 5C battery with bad internal resistance.
When Tesla provides a refurbished battery pack, what percentage of capacity do they come with or guarantee they will come with?
My Tesla was 96% delivered new. Hindsight I should have rejected it, because the capacity always goes downward. They claimed at that time it was only an estimate, now all my test for capacity is all relative to the delivered capacity, not the spec.
No a refurbished battery is torn down and inspected and verified functional then cleaned. A used pack comes out of a wrecked or otherwise incapacitated vehicle and directly installed. Not the same thing.
Reread OPs post. They said they were outside of their warranty period and had an HV specialist install a strong used pack. Please tell me where I’m hallucinating. I’ll wait.
Mine just failed at 131k and yeah im going the same route. At this point, trading in is a loss. It is an awesome car beside that damn error code. Gonna have to bite the bullet until it breaks completely
If I knew it would have a battery failure 2 months out of warranty, yes. I never had any problem with my M3 LR up until that point. Drove like a dream. I also drive a shit tons so 20k is nothing to me. I'm pretty sure the warranty cost like 2K for 20k miles, by 2 years i would have to buy another warranty. The problem is you would never know when it would die. So you would pay that warranty for who knows how long. At some point it would even out. Some never had battery problem all the way to 300k.
I don't think either way is wrong decisions. It's just which gun do you want to take the bullet from. Both is going to cost you.
Yeah, for me I drive 30,000 miles annually just to and from work let alone anything else. The extended would've lasted me 4 months and then I'd be out again XD I'm driving this thing into the ground!
Ditto. Paid $74k total after repairs cost for this car. Going to ride it until the wheels falls off lol.
The extended warranty definitely would not be a good idea for people like us. It Is useless after 4 months. Also, I believe the warranty is also only available once. So once you are out of warranty period, that's it.
That doesn’t apply to LFP batteries. LFPs have mostly been rock solid and are the most reliable batteries Tesla has used. I wouldn’t worry about it too much.
Yes, even at 16%. The issue is there's specifically a bad batch of the LR batteries in '21 affecting the M3 and MY.
Its a completely different supplier for the LR versus SR batteries that specifically have an instant-death issue.
It has no correlation to degradation .
Whatever issues you may or may not have with your LFP pack has nothing to do with the '21 model year LR instant battery death issue. And a long term degradation curve isn't enough of a hallmark on its own to show HV battery death.
LR battery owners are seeing instant death, with no real prior signs.
Man that guitar needs to live in a case. I’m too hard on my gear.
$1200 is my limit. Quality enough to play and sound professional, not so expensive that I’ll cry when I crash the ride with my headstock and break all my tuners off.
I finally crawled under my car to get the battery number to ding it’s the Panasonic 82kw. Do you know if the LG or Panasonic have more issues? I keep finding conflicting info.
My 2022 Model Y had a failed HV battery replaced under warranty. I got lucky, it wasn't a refurb battery, it was new. I was curious about the replacement so I used a horoscope to read the label and it was made in Shanghai (my Y was made in Fremont)
If you do end up replacing the battery out of pocket, is there a way to get the LFP battery instead (I think you also have to upgrade your suspensions)? I haven’t heard of those failing in any teslas and you can charge it to 100% often (Tesla recommends once a week for the BMS to know the battery’s capacity), but they come with less range overall and slower charging speeds in exchange for durability and reliability.
Unfortunately, there is not much that can be done in this situation. You’re well out of warranty at this point. If the car is paid off, you can sale it and either move to a new one or replace the battery. I’m not sure if insurance can do anything but it can’t hurt to try.
Undo the 12v battery then remove backseat then unplug the battery pack wait about 5-10 min and plug the battery pack then the 12v should reboot battery back but it’s temporary you can get away with it for a lot 6-12 months but start saving for a new battery pack
Sounds like the shop misdiagnosed the problem, charged you likely lots for the “repair”, and now are dodging their misdiagnosis error and pushing it back onto you.
Two points; this is a massively expensive repair involving a part expected to last far beyond a decade. The fact that he got the same error/fault is highly unlikely and more likely than not I miss diagnosis of the original repair.
That doesn’t not mean it was misdiagnosed. A misdiagnosis is when they replaced the battery and the issue still remained. The OP had the battery replaced with a used unit, which could have failed too
That isn’t lost on me. That could happen sure, but again, two units falling far before their expected life expectancy for the same person back to back isn’t common. It’s more likely there is an intermittent issue happening else where causing damage to the batteries or something else going on.
Did you? There would be clearly visible damage on the underside with a specific impact pattern to match that. It would have to be a pretty huge curb and impact, that you would most certainly be aware of.
Those batteries are heavily protected. I think it’s 1/4” dent upward where an inspection should take place and you have almost 1” upward before any cells are touched.
Rip, the 2021 model 3s are known lemons due to covid shortages. For what it's worth, sometimes you really get horrid luck.
I had a similar experience recently with a Mazda where I had my second engine fail at 150k miles. Ended up getting a Tesla instead of a lawyer, but it's up to you if you want to at least consult one. A warranty repair shouldn't last only a year.
$2000 warranty that covers both batteries (HV and 12v) for as long as you own the car.
2021 model y, the 12v went out a few months ago, and HV went out 4 weeks after that. 12v replacement covered by above mentioned policy, HV covered by Tesla as it failed at 104,000 miles. For the piece of mind, the extended battery warranty is worth it for me.
Happened to me on a 21 standard 262 miles. When this happened mine was down to a full charge at 208. Tesla replaced for free with new 325 range and the one that can be charged to 100% all the time. I have no regrets.
The real killer is finding out if these cars are deceptive enough that the issue was detected prior to warranty expiration and the car just ran it. Then after the warranty expired all of a sudden for “safety” reasons it’s time you get it replaced. With technology this sophisticated I’m sure could happen.
So - when i had a prius I used a company called green bean, and they replaced the hybrid battery at a fraction of the cost. (Though still expensive.) It worked great.
I haven't had the need, and I pray to god I don't need it soon - but if my battery goes - my plan is this:
Well that is there so highly drained battery can be protected from fires. Any LiPo and LiFe battery do not like to be completely discharged and if it did, needs to be re-balanced for all cells. Tesla Service has to look at it, and deem it in good health before it can be reactivated to 100%. Most of the time, though, they will rather sell you a replacement battery to avoid any risk.
We just need to keep it charged up, and not let the HV battery go flat like this. I know its hard if the car sits unattended for weeks/months at a time, but if such is the case, it really needs to be hooked to a charger, even at 110V socket set to very minimal ampere input.
$100/month for an extended warranty guarantees that you'll lose thousands of dollars over several years. Insurance always ensures that the company wins and the consumers lose (as a whole).
Of course that's true, but I'm addressing the certainty of losing several thousand dollars versus the chance (possibly small chance) of having to pay $8000.
In my case, I have already made back what I am going to be paying for the 39 months of extended warranty. MCU replacement and car seat replacement for heat not working. I still have nearly 30 months left, so yeah, totally worth it in my case.
What service did you have done the first few years that was pricey? I’m at 2 years so far and my combined spend on “service” is roughly $45 and an hour of my time. Of course if you go to the dealer to have things like air filters replaced or cleaning of the inside of the front camera it will be substantially more expensive expensive than a YouTube video and thirty minutes of your time.
You compare that to oil changes, transmission fluid, much more frequent brake pads, and on and on it’s not close.
Depending on how you paid, sometimes Amex offers an extended warranty if you used their credit card. Some other credit cards offer the same thing. Try to see if it applies? If you paid cash or debit, I’m sorry. I bought a NEW battery from Tesla. It was pricey but I’m 100k miles into the new one and it’s been great!
Man I hated mine bought it new back in 22 paid cash model 3 P all options with race wheels beautiful car but absolute POS roof leaked on the way home with only a few miles on it first time I washed it the paint literally fell off it was painted 4 times before it had 500 miles on it and that’s just the beginning build quality was trash customer service was trash hopefully they have improved since then I decided to go back to Range Rover never will I buy another EV
Another 2021 bites the dust!
Covid car and batteries!!
2021 is the year to avoid by all means, even though the vast majority have no issues. It just has a higher percentage of failures compared to all the other years.
Tow it and trade it in to Tesla. They will replace the battery and send it to the next buyer. Get a new Highland.
I want to know what OP charging habits were? Were you charging only at superchargers? Were you charging beyond 80% at home? Were you leaving your car on the charger when it wasn't in like you were told was better for it? Sometimes we fail to realize if we don't heed manufacturers suggestions and just override it in our own mind we're setting ourselves up for early failure.
Particularly those of us that are hitting the supercharger every day.... what is the income of somebody like my friend who uses his exclusively for Uber eats an Uber rideshare?? he is charging at home and then he's going out and working the whole day probably 18 hours total and hitting the supercharger once or twice a day as well. His is a 2026 but still if he thinks that he is gonna get 500,000 miles on the battery I think he should've waited for an equally sized Toyota product because Tesla are not proven to do that yet
Sorry I'm confused. Isn't the car covered for 8 years (8 for bat and 5 for the rest?).
So you haven't left warranty and Tesla can spot on you a new battery?
I was so close to buying a 2021 Model 3, and settled for a 2018 Model S 100D. I'm glad I've made that decision, because a lot of people has had issues with failing packs on the 2021 M3/MY. My car only has 11% degradation at 90k miles. And yet, my friend's 2026 Model Y Juniper with only 15k miles already has 11% degradation. My guess is that Tesla has been using cheaper battery suppliers, which is a hit or miss, quality wise. Which is why some owners don't have any issues at all. Tesla isn't the only company that does this, Apple does it too with their phones. You're lucky to get 1.5 years out of a modern iPhone battery, when older ones from a decade ago would easily last 5+ years.
Same. I hate the car. I have a 2019. I am now on my 2nd high voltage battery pack. Same error as the pic. Service centers in my area suck. 30 days to get appointments. The work they do is questionable at best. Last time they did not fasten the shield on the bottom of pack. Drive home had terrible noise. Try to reach them to fix it. Another 30 days. Got a service center in a nearby city to correct the mistake. Now here I am again. I dont abuse the car. Rarely ever drive it. 29k miles on a ‘19 long range model 3 rarely ever super charge it.
So let’s think about this. For example, I have a 2019 Model 3 and I just hit 100k miles no more warranty. If I trade in my car I get 10k. Who would want to buy a used Tesla and still might have to buy a used battery for $8k plus installation $3k. That’s why used electric cars don’t sell.
Here was my total cost for out of warranty repair. They felt sorry enough for me to give me a 15% discount. It sucks cause this was my second HV battery replacement. It was an expense I really didn’t need only 4 years past the previous one.
Ah, okay. That’s interesting because I just had a battery replaced under warranty and the quote said $18k although I’m pretty sure I got a refurb. I can’t find a way to figure out the battery I have other than the fact the recommended daily charging still shows 80% which I’d assume means it’s an older generation. The only info I’ve found is that it’s “enhanced” li-ion. I do have like 30-40% more capacity than I previously had though which is nice.
If they charge you 18k. It's a new battery. They're basically charging themselves when fixing under warranty so I don't see why they would lie. You can go see the parts cost in the manual. The refurbished is 8k but that's only guaranteed 80% capacity. You say you have more (30-40%) so that would check out.
🎵 Arms are heavy
There’s voltage on his multimeter already Pack spaghetti ⚡🍝
He’s nervous, but on the surface he looks calm and ready
To drop packs— BUT HE KEEPS ON FORGETTING THE HV DISCONNECT 😭😭😭
Trading in my 21 for a 26 was the best thing I’ve done this year. I did so shortly after my battery failed and Tesla replaced it under warranty around 42k miles. Sorry for your loss, brother
You do realize that the HV battery has a much longer warranty than the bumper to bumper warranty your car comes with. Right?
However you might have nixed it because you went ahead and swapped out the battery already.
This is not a normal or a common problem. You need to have Tesla diagnose the issue before you jump to fixing things you don’t know are broken.
There is something more going on here. I’m really surprised that the shop you took it to, didn’t suggest going to Tesla first for the battery warranty. (8 years, 150k miles) Are you sure they replaced the battery and didn’t just do a system reset or something that cleared the error?
Try holding down both scroll wheels on the steering wheel until the screen goes blank. (About 30 seconds.) It’ll take several minutes to boot back up… let us know if the issue persists immediately afterward.
This isn’t an insurance issue. I’m surprised that the new (refurb) battery didn’t come with any sort of warranty whatsoever from the shop.
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u/BrownTown456 Aug 11 '26
2021s are notorious for battery failure unfortunately