12v Battery Warning - what to do about it?

12v Battery Warning - what to do about it?

I can't seem to find any information on this - the waring just showed up to the dashboard 2 days ago. Does anyone know what this means and how quickly I need to take care of it?


- brad

lilbean | July 1, 2017

I would take it to the SC right away. I think I've read you have a month or so though. I forget.

lilbean | July 1, 2017

I have heard that the battery could fail without the warning too.

Solarman004 | July 1, 2017

Take it in immediately. There are a handful of of posts here and on Tesla Motors Club of this leading to sudden shutdown and inability to restart. In most cases I've read, the issue was not the 12V battery, but the DC to DC converter or related cables that keeps the 12V battery charged by the traction battery.

You may want to contact the SC before driving it again...they may want to tow it in for diagnostics and repair.

rich.j | July 1, 2017

Check with your SC. I had to have my X towed in immediately upon seeing that warning. I was told its nothing to mess with as if the 12v battery goes dead you lose the ability to drive.

mzero | July 3, 2017

Wonder why the 12v battery still needed given the car already has a huge pack in the belly? Tesla should just do away with this entirely

psusi | July 3, 2017

Because the 400 or so volt battery pack has to be disconnected to safely power down the car, leaving the electronics running off of the 12v battery. I've had the 12v battery die in my Prius before and the first time it was not fun. Could not even disengage the parking break to push it out of the garage so I could get jumper cables on it. Had to use the emergency mechanical key to open the driver door, then climb into the back and tear the panneling off to manually open the trunk so I could replace the 12v battery. After that I started regularly checking it ( service mode has a nice readout of the voltage so I didn't even need to pop the hood ), and the next time it was starting to go I caught it early and replaced it with a better after market battery.

Does anyone know how to get the Tesla into service mode and see the 12v battery status? ;)

Lubdub | July 4, 2017

if cant get it to the SC asap
open the area just below the windshield wipers
there is a plastic cover the 12v battery is right there
check that the battery to ground cable nut is tight
I had all kinds of dumb electrical issues till I fixed that minor issue
do not over-tighten.