That is impressive. :up:Good question!
According to data recorded by Plug In America (PIA), Roadster battery packs are retaining around 80 to 85 percent capacity after 100,000 miles of driving--greater capacity after far greater distance than Tesla was expecting. It equates to a loss of only around 0.15 percent on average every thousand miles.
Tesla's own 2006 predictions were for 70 percent retention after just five years and 50,000 miles, according to Plug In America's chief science officer, Tom Saxton.
Better still, climate doesn't seem to have much of an effect on battery life.
"Roadster owners in hot climates are not seeing noticeably different battery capacity profiles than owners in moderate climates," said Saxton at the Teslive Tesla users conference where the findings were released.
Those contrast with the findings of Plug In America's last battery life survey, on the Nissan Leaf.
I also have a Leaf but am only leasing it. Originally, the Tesla warranty didn't include much on the battery. After them seeing the Roadsters hold up to hundreds of thousands of miles they decided that it wasn't much of a risk to include the battery under their standard warranty.
It's almost at 17,750 miles now and still goes 240 miles on a single charge in range mode. Standard mode is somewhere around 190 miles. As long as you remember to keep it charged and don't let it sit at 0% battery for extended periods of time, it isn't likely you'll need to ever even worry about the battery. I've had zero issues with the car. The only real maintenance you'll need to be concerned with is keeping air in the tires!