Seems really strange so many people suddenly getting this issue? I bought a CPO S85 a year ago - love the car but suffered the battery issue. I started with a range of 237 on a car with 12000 miles. After software update this dropped overnight to 207. Tesla said this was nothing unusual but then out of the blue I get this warning. Tesla have recovered the car and given me a nice loaner, and I'm waiting to hear what they say. After the warning the car wouldn't charge beyond 75 miles, so exactly the same as everyone else. Coincidence?