I and someone I followed on Twitter also bought our Model 3 LR RWDs very early in 2018. He traveled all over the country with his and had about 140,000 miles on it early this year. At that time he got the alert to replace the 12v battery. Mine is currently at 95,370 miles and I'm still on the original battery.
I'm at the extreme end I guess as someone who has only managed to do less than 1500 miles a year in my car. Needless to say my car can be parked up for several days, asleep, without turning a wheel.
Wow, so basically it seems 12v life is pretty random. I'm over 40k, and 49months since date of mfr., I have a spare 12v I picked up at a SC, and carry a 9v in my pocket, and have been waiting for the alert ever since 36months, but I'm thinking it must be time to swap it out.
If you really are carrying a battery around, carry an A23- it's a lot smaller, 12V, and will open the frunk just fine once or twice.
From what i see it seems to be people who live in hot areas tend to need the replacement sooner then those that don't. I wonder we ran a survey of park it out in the sun all day vs a garage in a hot climate would that paint an even clearer picture of how soon the battery should be replaced
Did you go out and buy a lottery ticket?
Probably from the same batch. But even within the same batch you're going to have units that are uncommon parts of the bell curve.
Just get a tester and test it regularly, like once every month to 3 months, and run a test immediately before any road trip. It's not going to go from healthy to dead in a matter of a week or two. The moment the tester shows the battery getting weak, replace it.
That's just asking for trouble lol. It's happened to me with a previous vehicle. Battery is good two weeks later stone cold dead. I don't have time for that and no I've zero intention of testing the battery every other day or week just to save a few $ I'm just not that cheap.
Which tester do you have? I'll add that to my list of ones to avoid. And what was the last measured SoH and SoC of that battery and how long did it sit without being charged?
You realize that all electronic devices have a few instances that suffer from "infant mortality" right? Replacing the battery after x months does not guarantee that it won't die on you and just gives you a false sense of security.
Let's not be hyperbolic about the way it can happen though. It will not strand you "on the side of the road". A 12V battery failure will never stop a moving Tesla. The only real way this happens is when the car goes to sleep, which is after it's off for ~15 minutes, and often even much longer.
Pretty much did the same. Took it in for something else and asked them about paying for a replacement (mine was at about 3.5 years). After they were done the guy told me they replaced the battery but because it was still under warranty there was no charge.
