Forum members post almost daily with the same concern, but I don't recall hearing of someone with a defective battery pack. I'm sure there's a few out there but I would say it's a very low probability that your pack is defective. Likewise, if it was, I wouldn't expect the failure mode to be catastrophic, meaning the capacity would likely just keep degrading but it wouldn't leave you stranded on the side of the road.
Well I’m not concerned of getting stranded, I’m just making sure my $70k Tesla can get the range I paid for. 291 miles is whah they advertise but if I’m barely getting 268 after a few months, that sucks.
Today I drove to work on chill mode and was feathering the pedal. My displayed range started at 190 and I drove 5 miles and now it’s 180... that’s with no AC.