When to Replace 12v?

[dude7]

For safety reasons (and probably regulatory too), the HV battery has to be isolated when the car is "off". Which means you need a power source to run whatever mechanism connects it to the rest of the system (a high-current switch of one type or another).

OTOH, it's not like there's no circuitry on the battery side of the HV switch; all the battery management system is there. So maybe you could find a mechanical or optical way to communicate to the HV side that you want to close the main switch, and it could do it using its own power. You'd have to think about the safety implications, but it might be possible.

I found out the hard way that I can't "jump start" my Model Y with jumper cables. In an ICE car, you can simply use another 12v source, e.g. another car, by attaching jumper cables to turn the starter motor. There's no equivalent functionality in my Model Y where I can attach another 12v source, e.g. my other car, to get my Model Y to get the HV switch to contact. Tesla built in a mechanism to open the frunk by using a 12v battery, but no corresponding function to start the HV battery. Maybe I should have tried to disconnect the 12v battery after charging it and reconnected it, but again, this happened when my car was parked outside during a historic, national newsworthy rainstorm. In any case, if this happened away from my house, I would NOT have the tools to disconnect the 12v battery anyway, so it's a half-useless point.

 

[j2048b]

I replaced my battery today from orielly’s auto parts store they cross referenced the original part number and i got one of their own batteries… so hopefully everything will go as planned and the new battery wont cause issues and be just as good as the one telsa installed…

 

[Watts_Up]

I replaced my battery today from orielly’s auto parts store they cross referenced the original part number and i got one of their own batteries… so hopefully everything will go as planned and the new battery wont cause issues and be just as good as the one telsa installed…

What make you decide to change your battey (warning on the display, just peace of mind, could not open any door..)?

What type (Flooded, EFB, AGM...), maker, part number, capacity, and price?

 

[Midnightsun]

I believe any group size 51R is the correct replacement battery. I would stick with flooded as charging parameters vary with other variations. Although the charging parameters are only very small, it would be wise the not confuse your Tesla.

 

[Pianewman]

I replaced my battery today from orielly’s auto parts store they cross referenced the original part number and i got one of their own batteries… so hopefully everything will go as planned and the new battery wont cause issues and be just as good as the one telsa installed…

It would be helpful if you would post your car's year, model, when you bought it, and mileage.

 

[Dennisis]

I replaced my battery today from orielly’s auto parts store they cross referenced the original part number and i got one of their own batteries… so hopefully everything will go as planned and the new battery wont cause issues and be just as good as the one telsa installed…

FWIW, it's really not worth the trouble to replace the battery yourself. Mobile service will do it for you for around $100 and then you won't have to worry about compatibility or other issues, not sure of the warranty.

 

[JayPaul]

I month ago, I had to replace the 12V in my '21 TMY. It was the original. I got a notification on the screen to replace the battery on a Friday night, there were a few other error messages in addition to the replace the LV Battery. I went first thing Saturday morning and had it replaced under warranty at my local SC. They were done in 15 minutes.

 

[cbdream99]

FWIW, it's really not worth the trouble to replace the battery yourself. Mobile service will do it for you for around $100 and then you won't have to worry about compatibility or other issues, not sure of the warranty.

Warranty is one year.

 

[Mulkogi]

I month ago, I had to replace the 12V in my '21 TMY. It was the original. I got a notification on the screen to replace the battery on a Friday night, there were a few other error messages in addition to the replace the LV Battery. I went first thing Saturday morning and had it replaced under warranty at my local SC. They were done in 15 minutes.

Covered under the 5 year warranty?

 

[JayPaul]

Covered under the 5 year warranty?

Yes!

 

[Pacernow]

On Friday, June 7th at 3:30PM I received a notice on my Tesla app that the 12v battery needed to be replaced. I sent a notice to service and received a response that a mobile tech would be at my house by 5:30PM that afternoon. The tech arrived about 5:30 and replaced the battery. I mentioned to him that the battery he was replacing had been installed in August 2023. He sent the service department a warranty request and I was not charged for the new battery. The tech left my residence before 6PM. I have a 21 MY LR AWD with 99K+ miles on the odometer. Can not complain about Tesla service in East Texas. Great job!