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Will Tesla Stop Using 12 Volt Lead Acid Battery as the Warranty Replacement?

Why are you so worried about this battery?

It should not be a big deal to recover if you take some basic steps to have backup (ability to detach negative terminal, emergency jumper battery, & 12V hidden behind tow hook cover). Haven’t tried it though!

Also it often (not always) fails gracefully.

And replacements are cheap. Initially I worried about it on road trips but it seems you can just disconnect the 12V and then you *might* be fine. YMMV.

I do wish that someone with one of the new batteries would measure the vampire drain with the new setup and using the known battery parameters (capacity, discharge curve, etc.) determine average sleep power.

no need, cars been patched. If 12V goes down the car continues to work normally but just doesnt go to sleep.
 
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That’s what happened when mine failed, but there still appear to be failure modes for the 12V which the car cannot detect. Possibly quite rare - but they do seem to happen.
There has been report in the past the dc-dc inverter fuse blown and the whole thing bricked. Tesla charges couple of grands to replace the inverter but someone discovered it can be repaired..
 

AlanSubie4Life

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Oct 22, 2018
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It says to just connect it to the battery terminals and follow the instructions on your jump starter.

Worth noting there are multiple reports that it is a good idea to disconnect the negative battery terminal from the 12V battery when performing the jump (I don’t think this is covered in the manual?). If your battery has failed, with the various checks Tesla has in place to prevent shutdown, the failure is likely to be quite catastrophic. They just keep catching more and more failure modes and escaping failure, so the ones they don’t, which require jumping, are likely the most severe (things like shorts that result in thermal runaway and battery destruction in a short time period). So good to disconnect the negative terminal and take the battery out of the picture in those cases, since it is probably in very bad shape.

The manual does have this somewhat ambiguous note which covers this case, but it may be tried only after you have exhausted your emergency jump, which is why this should be (arguably) done first…hence the need for a 10mm wrench:

35285FF4-2EFA-48CB-9FF5-79E498437CE0.jpeg




Agreed on the need for the disconnect. I think it is just good to be aware of because if you have battery troubles and you recover your car to a working state, you’ll need it when you go to replace the battery.
 
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Isn't it obvious? Tesla has had known issues with this battery. I don't want to be stranded someplace without cell coverage in the middle of the night. Or end up missing an appointment because the 12volt battery died and I never got a warning that it was going bad. Worse yet, packed up and ready to go on a trip and it dies, then being told by Tesla that they are out of 12volt batteries and it could be a couple weeks or they have them but they can't get someone to me for a few weeks either.
Catastrophize much? You’re describing what happens to any car when the 12v dies. In fact, a Tesla performs better than an ICE with a dead battery since it will likely just keep the car awake on the traction battery. Plus it almost always gives a warning on recent software updates.
 

Resist

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Mar 24, 2019
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Catastrophize much? You’re describing what happens to any car when the 12v dies. In fact, a Tesla performs better than an ICE with a dead battery since it will likely just keep the car awake on the traction battery. Plus it almost always gives a warning on recent software updates.
Again, the Tesla Model 3 lead acid battery has a documented higher than normal failure rate. So yeah, that's an issue for me.
 
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AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
14,896
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Again, the Tesla Model 3 lead acid battery has a documented higher than normal failure rate. So yeah, that's an issue for me.
It thrashes on the battery for sure. Hopefully you have learned from this thread some mitigation strategies to eliminate worry. And you can even test them in your own garage in advance if you wish, to make sure they work.

I no longer have fear of going to remote places. My battery failed once, it was no big deal, car drove fine, Tesla replaced at my house within 24 hours, and I am prepared if this should happen on a road trip. The car does not need a 12V battery once it is operating; you can remove it.
 
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Resist

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Mar 24, 2019
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It thrashes on the battery for sure. Hopefully you have learned from this thread some mitigation strategies to eliminate worry. And you can even test them in your own garage in advance if you wish, to make sure they work.

I no longer have fear of going to remote places. My battery failed once, it was no big deal, car drove fine, Tesla replaced at my house within 24 hours, and I am prepared if this should happen on a road trip. The car does not need a 12V battery once it is operating; you can remove it.
Unfortunately, getting a replacement battery from Tesla within 24 hours just won't happen anymore. How long ago was yours replaced?
 

ucmndd

Well-Known Member
Mar 10, 2016
10,110
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California
Unfortunately, getting a replacement battery from Tesla within 24 hours just won't happen anymore.

Objection, speculative. I walked into a service center in July and had a replacement in my hands in 20 minutes.

Catastrophe averted. Come on out to the Fresno service center, they’ll take care of you. I’ll buy you a beer while you’re here. ;)
 

P3dStealth

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Nov 12, 2019
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Worth noting there are multiple reports that it is a good idea to disconnect the negative battery terminal from the 12V battery when performing the jump (I don’t think this is covered in the manual?). If your battery has failed, with the various checks Tesla has in place to prevent shutdown, the failure is likely to be quite catastrophic. They just keep catching more and more failure modes and escaping failure, so the ones they don’t, which require jumping, are likely the most severe (things like shorts that result in thermal runaway and battery destruction in a short time period). So good to disconnect the negative terminal and take the battery out of the picture in those cases, since it is probably in very bad shape.

The manual does have this somewhat ambiguous note which covers this case, but it may be tried only after you have exhausted your emergency jump, which is why this should be (arguably) done first…hence the need for a 10mm wrench:

View attachment 850014



Agreed on the need for the disconnect. I think it is just good to be aware of because if you have battery troubles and you recover your car to a working state, you’ll need it when you go to replace the battery.

That warning is only for the 15v lithium battery. There are two sets of instructions. You read the wrong one or just read both since they are one right after each other in the manual. The lead acid is jumped like a normal car. The 15v lithium it says to only connect for 20-30 seconds. It times out after 30.

I am guessing they give you a 30 second window to pull your 12v jump pack off the 15v terminals before the car turns on the inverter and starts charging the 15v. If you don't pull it off after 30 seconds it times out and shuts down. It would make sense for them to not want to put the wrong charge into the jump pack. That's my theory on that anyway.

I don't have a 15v though. Happy with my 12v. Who knows... maybe in a few years my 12v ends up being the cheaper version. Anyone know how much a 15v costs?
 
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jjrandorin

Moderator, Model 3, Tesla Energy Forums
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Nov 28, 2018
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Unfortunately, getting a replacement battery from Tesla within 24 hours just won't happen anymore. How long ago was yours replaced?

Did you already try to buy one? All the other discussion you have had in various threads on this topic sounded like you were not going to buy one but wanted to wait for it to fail, yet upset about the fact it might fail.

I got one within 1-2 days after putting in a service request for one, installed in my driveway while I took meetings. The price, installed was $129 out the door. The battery itself was $85, which is cheaper than any battery for any other vehicle I have had in the past 15-20 years.

I paid to replace mine, because I was concerned about early failure (like you sound like you are as well). I felt that $85 was cheap enough for a consumable product (car 12v batteries are consumable products) and I felt $129 replaced in my driveway without some sort of "penalty fee" for home service, was fantastic.

Your choices are:

1. Keep worrying about it and doing nothing, and wait for it to fail to hopefully get a warranty replacement (Save $85)
2. Pay to proactively replace it ($85) and install it yourself
3. Pay to proactively replace it and tesla install it ($130)
4. Get an aftermarket 12V lead acid battery ( > $85 ) and install yourself
5. Get an aftermarket li ion battery, ( >$400+) and install yourself, and roll the dice it wont be impacted by tesla changing charging algorithms (tesla has NO obligation to try to make aftermarket lithium ion batteries work, in cars that came with lead acid batteries)

Thats basically it. There is no option to get tesla to install a li ion battery in a car that didnt come one, and there likely wont be one in the future. There is no reason for them to do it. Even if they do, it absolutely wont be a warranty replacement.

If you are actually worried about it (like I was) then perhaps you should replace it on your dime. Its inexpensive, as far as batteries go. If its not worth $85 to you, then it doesnt sound like its that important to you, multiple thread posts notwistanding.
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
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San Diego
That warning is only for the 15v lithium battery. There are two sets of instructions. You read the wrong one or just read both since they are one right after each other in the manual. The lead acid is jumped like a normal car. The 15v lithium it says to only connect for 20-30 seconds.
I realize that. I didn’t read the wrong section, and realized that might not apply to the 12V (I know where it was!). That’s one of the reasons I said it was ambiguous.

In any case, my point was it should! Hopefully you get my point here - as I said what that note even means is extremely ambiguous - to me it says to disconnect the low voltage battery. But no instructions on doing so (regardless of how trivial).

Anyway I think that disconnection (for the 12V) should be done by default, rather than even attempting a jump, for the reasons outlined. Just don’t want to lose sight of that, which was the point. YMMV, not a recommendation.

Obviously only in the case of disablement. Mostly a non issue. Car fixes itself.
 
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RayK

Safety Score 90 (Was 96!)
Apr 5, 2016
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My experience so far with the Tesla 12V battery was to do a proactive replacement one month before the four year warranty ran out. I never had any problems with it, nor did I get any warning messages. I simply decided that it was worth the ~$130 to have mobile service swap it out. I was going on a long-ish trip to Southern Oregon and didn't want any chance of the 12V acting up (Murphy's Law, you know). My understanding is that the replacement battery is only warrantied for one year, which doesn't seem right but it is what it is. Based upon the comments I've read here in the forum, I will probably wait another 4 years before looking at replacing it again. Maybe by that time a better and cheaper aftermarket Li-ion substitution will have been designed and I'll consider it. I did not go with the current offerings (e.g., Ohmmu) because of the seemingly whack-a-mole game that has gone on with firmware updates negatively affecting Li-ion 12V batteries.

My previous car, a 2000 BMW 323i, went through at least three batteries (original and two replacements). I had installed an aftermarket 12-disc CD changer in the trunk and the interface between it and the BMW's power system sometimes did not fully power off. Leaving the car idle for several days was enough to drain the battery. I would be able to charge the battery but it would eventually degrade enough to not accept a recharge. I don't remember the price for those batteries but I'd wager they were more than $130.
 

P3dStealth

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Nov 12, 2019
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I realize that. I didn’t read the wrong section, and realized that might not apply to the 12V (I know where it was!). That’s one of the reasons I said it was ambiguous.

In any case, my point was it should! Hopefully you get my point here - as I said what that note even means is extremely ambiguous - to me it says to disconnect the low voltage battery. But no instructions on doing so (regardless of how trivial).

Anyway I think that disconnection (for the 12V) should be done by default, rather than even attempting a jump, for the reasons outlined. Just don’t want to lose sight of that, which was the point. YMMV, not a recommendation.

Oh yeah for something like a serious internal fault in the battery you are right. If my battery was hot or swollen I'd personally pull it out and jump the car without it.
 
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jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
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don't remember the price for those batteries but I'd wager they were more than $130.

I paid something like $350-400 for a battery for a BMW 535, and then when BMW wanted to also charge me an hour labor (like $125-150 if I remember) to code the battery to the car, figured out how to code it myself. This was 2013 or so.

Perhaps thats why I feel most things on teslas seem reasonable. Coming from so many years of BMWs charges, everything is cheaper than that. If someone is coming from honda accords, toyota camrys or something like that, I guess it would seem more expensive. I had an altima battery that cost me more than $85 though, so.... shrug.
 
It thrashes on the battery for sure. Hopefully you have learned from this thread some mitigation strategies to eliminate worry. And you can even test them in your own garage in advance if you wish, to make sure they work.

I no longer have fear of going to remote places. My battery failed once, it was no big deal, car drove fine, Tesla replaced at my house within 24 hours, and I am prepared if this should happen on a road trip. The car does not need a 12V battery once it is operating; you can remove it.
i had to wait 3 weeks for mine... was completely fine, car just didnt sleep and front usb ports broke - as the fuses dont reset without sleeping.
 
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Objection, speculative. I walked into a service center in July and had a replacement in my hands in 20 minutes.

Catastrophe averted. Come on out to the Fresno service center, they’ll take care of you. I’ll buy you a beer while you’re here. ;)
I have the same doubts about battery shortages. I got mine (S not 3 but they also have 3) replaced at SC last week, no appointment is needed and there should be buffers between warnings and completely dead battery. The shortages or lack of warnings may be a problem in 2020, but is it still true today? Also, Tesla has addressed the issue partially by firmware updates. There is also mitigation strategies ... at least you have some warm and fuzzy feelings that this is not a guaranteed doom.
 

Resist

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Mar 24, 2019
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Did you already try to buy one?
No, because it's a 2 hour drive to the closest service center and they no longer have a phone number to call and talk to a person. Don't want to drive all that way and then be told they don't have the battery in stock. And I'd rather replace it myself but, ideally if it was a warranty replacement and cost me nothing that would be even better. I ordered a battery monitor and it arrived today, so I'll install that and at least be able to keep an eye on the condition of my 12V battery, which will ease my concerns and probably give me enough time to get a replacement battery if it was warranted.
 

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