12v power low vehicle may shut down unexpectedly

12v power low vehicle may shut down unexpectedly

My 2019 Tesla Model 3 purchased 5 months ago, suddenly gave a warning on the highway that the “12v power is very low and vehicle may shut down unexpectedly”
The car had been charged with 250+ miles of range. Once stopped the car wouldn’t respond and even flashers wouldn’t work. Their support staff did not know how to fix this or even how to keep flashers on. Luckily I had exited the highway into a residential area where flashers weren’t necessary. This is sudden and dangerous.

Reading on other forums, many have had this problem. If the batteries are bad, Tesla should be able to replace them proactively working with their suppliers. If the batteries aren’t bad then it has to be the charging system. Instead they just replace the batteries. Some users have had this happen multiple times and a few have gotten Tesla to replace the charging system.

I find this appalling product reliability and poor engineering. A battery can be monitored and failure can be detected several charge cycles (days) in advance. Tesla needs to do a recall to fix the charging system and install a proper monitoring system for the 12 volt. Replacing the battery is just putting the driver at risk of being stranded again.

I have filed a report with NTHSA. If you’ve experienced this, you should too. I now feel I cannot rely going any distance from my home in my Tesla.

terminator9 | 18 août 2019

I have had the same issue in the last month. Luckily, it's not to the extent where car refuses to drive. The message flashes on the screen often which driving.

First visit to service center - Kept car for 4 days. Could not duplicate issue. No changes made. Come back if the issue comes back.

Issue came back in less than a week.

Second visit - Kept car for 2 days. Changed the 12v battery anyway although it wasn't showing low voltage.

Issue came back within 2 days but it was only for 2 seconds. I guess I will have to wait until the message is more prominent on the screen so can they can see it more but I can only assume a third visit will happen very soon :(

Magic 8 Ball | 18 août 2019

Sigh, over 300K units on the road without issue. A tiny fraction may have similar issue.

jstat10 | 18 août 2019

I have had several 12 volt car batteries fail suddenly over the years. It is annoying, but it doesn't seem to be a uniquely Tesla problem.