12v battery issue, Tesla unsatisfactory response

[Daniel in SD]

I could actually buy a battery and change it, when you call around to ALL local part suppliers and ask for a Tesla 12v battery they have no options. Do you not see the difference? I’m not trying to be bitchy here at all it’s just crazy 1- the difference from a few years ago with service and 2- that you get zero warning and your car in not movable.

I have owned a ton of cars and non perfect, tsla has been amazing it’s just really bad and weird when you can’t fix something yourself. And yes I know there’s a lot of people who can fix their own 12v and are super smart etc etc. I am apparently not

I agree with you. The user experience for 12V battery failures is crap relative to other vehicles made worse by the fact that they happen more often.
A lot of people don't want to have to do research on the internet to figure out how to get their car running in less than two weeks. If Tesla is going to discourage third parties from working on their cars they need to have timely service.

 

[vickh]

Maybe we should just proactively be replacing the 12V battery every 1 or 1.5 years.

yes mine was proactively replaced at SC when I was there for something else in 11 mos. Tech said they smelt Sulphur (i think it was my stinky ac). It gets to be a 120 in garage here though

Once out of warranty I'd get a AGM or LiOn. They should have made it easier to replace or allow 12V jumping from the inside . Is it the same on the X/Y ?

 

[Brovane]

The 12V battery on my 2015 Leaf lasted about 3 years. The 12V died on me with no warning and left me temporarily stranded at a shopping center. I called AAA and within 60 minutes a battery tech came out and replaced the 12V and the car was drivable again.

 

[vickh]

The 12V battery on my 2015 Leaf lasted about 3 years. The 12V died on me with no warning and left me temporarily stranded at a shopping center. I called AAA and within 60 minutes a battery tech came out and replaced the 12V and the car was drivable again.

We have AAA too. Hope they know what to do/stock Model 3 batteries. Tesla needs to standardize basic car functions. Same problem in car washes.

 

[Silicon Desert]

Battery Day is in two days and I hope that Tesla will also, perhaps, announce something related to a new ability to DROP/REMOVE that friggin' 12-volt battery, forever?

Pretty sure you will never see any EV get rid of the 12V battery for some reasons you may or may not have considered. Yet, I would prefer that the 12V battery be used for a reserve emergency use rather than being actively discharged and charged. That too would have a few issues, but not as bad as now.

 

[vickh]

Yeah, that's the one. I bought one from AEG but it uses the same app and is essentially the same device. Easy to setup with the exception that the positive lead on the 12v is a little tricky to connect the clip and then put the red rubber cap/seal back. I bent the clip in an L shape and managed and also used some waterproof electrical tape to make sure it would stay in place.

any recommendations for internal ones I can plug into cig. light?
Amazon.com : bluetooth car battery monitor

 

[vickh]

Pretty sure you will never see any EV get rid of the 12V battery for some reasons you may or may not have considered. Yet, I would prefer that the 12V battery be used for a reserve emergency use rather than being actively discharged and charged. That too would have a few issues, but not as bad as now.

old Roadsters got rid of the 12V battery. Tesla should at least emergency power the car thru HV so you're not stranded

 

[Gbee]

If i take delivery of my 2020 Model 3 at the end of the month. Does this 12v issue affect all the model 3's or just some with a certain software update that ruined the 12v battery

 

[SeanM]

Aren't the 12V batteries usually under at-least a three years warranty? Doesn't Tesla offer the same warranty on the 12V batteries that come with the car?

 

[RayK]

any recommendations for internal ones I can plug into cig. light?
Amazon.com : bluetooth car battery monitor

Not knowing exactly what's in between the 12V and the "cigarette" lighter, I would recommend clamping something directly to the 12V. I recently bought one of the voltage loggers that was referenced in another thread here but yet to get enough incentive to actually put it in my car.

old Roadsters got rid of the 12V battery. Tesla should at least emergency power the car thru HV so you're not stranded

And I believe that the reasons why Tesla soon reverted back to the traditional independent 12V battery is that it caused the HV battery pack to become unbalanced and for safety reasons in case the HV pack was disconnected, either through accident or other unintended causes.

edit: I have the Omega OM-EL-USB-3 data logger. The measurement range is 0V-30V with just over 32,500 data points. Sampling rate can be set from 1s to 12hr. I would have liked to have an even shorter sampling rate but at the 1s interval, a 9 hour span can be measured and logged. Hopefull 1 second should be fast enough to see any voltage spikes that might occur.

 

[one2many]

OK now that we have the 12v battery fear out there, I can see myself saying,
sorry butter cup, my model 3 is showing errors, I guess you will need to stay here
for the night.

 

[Pingpong]

Wouldn't this same scenario have been the case with any other car with a dead 12V battery? This doesn't seem to be a Tesla specific problem.

 

[Daniel in SD]

And I believe that the reasons why Tesla soon reverted back to the traditional independent 12V battery is that it caused the HV battery pack to become unbalanced and for safety reasons in case the HV pack was disconnected, either through accident or other unintended causes.

Yep. What I've always wondered is why they can't just keep the DC-DC on all the time.

Wouldn't this same scenario have been the case with any other car with a dead 12V battery? This doesn't seem to be a Tesla specific problem.

Yes. The issue is that if you go to an auto parts store and ask for a new battery they'll look at you like you're crazy. So you've got to search on the internet to figure out which battery to get. If you call AAA I doubt they'll replace your battery either.

 

[Logman]

Wouldn't this same scenario have been the case with any other car with a dead 12V battery? This doesn't seem to be a Tesla specific problem.

Isn't the problem also that you can't even open your doors if you have no 12V in a Tesla?

 

[one2many]

So as I understand it they wanted to have two systems. Almost all car stuff is 12v
and the HV system should not be included in that system. It is sort of a cost thing.
If you go to 0% HV the 12v system will allow you to charge. The 12v system failure
was not taken into account.

 

[vickh]

Isn't the problem also that you can't even open your doors if you have no 12V in a Tesla?

+ you can't even open the frunk without some "surgery" unlike a reg. car. manual release.

 

[one2many]

Yep, crazy but true

 

[vickh]

Not knowing exactly what's in between the 12V and the "cigarette" lighter, I would recommend clamping something directly to the 12V. I recently bought one of the voltage loggers that was referenced in another thread here but yet to get enough incentive to actually put it in my car.
And I believe that the reasons why Tesla soon reverted back to the traditional independent 12V battery is that it caused the HV battery pack to become unbalanced and for safety reasons in case the HV pack was disconnected, either through accident or other unintended causes.

edit: I have the Omega OM-EL-USB-3 data logger. The measurement range is 0V-30V with just over 32,500 data points. Sampling rate can be set from 1s to 12hr. I would have liked to have an even shorter sampling rate but at the 1s interval, a 9 hour span can be measured and logged. Hopefull 1 second should be fast enough to see any voltage spikes that might occur.

not clamping but something like this: https://www.amazon.com/dp/B0769G4JGD/

I have one for my old highlander but like you said not sure how accurate volt reading would be for Tesla battery health

 

[TheRFMan]

I wonder if these 12V failures are more common in cases where the cars are only plugged momentarily for a charge and then left unplugged for a number of days. There is no reason to not keep a float charge on the 12V when the car is plugged in, even if not charging the HV pack at the time. I understand that the DC-DC converter can't do its thing when the car is in sleep mode, so perhaps there is value in keeping the car plugged in whenever parked, and somehow find a way to prevent it to go into deep sleep too often or for too long, such as charging at the lowest current setting that will bring you to 80 or 90% by the time the car is needed (although that may cause other issues).

 

[SMAlset]

+ you can't even open the frunk without some "surgery" unlike a reg. car. manual release.

Plus and minus to that really. In general it does keep your frunk somewhat more protected if the car is vandalized and the guys aren't familar with the car. Also takes longer for them to gain access than pushing some manual release. They always want a quick in and out and not seen hanging around.