Why would you base your assumption on experience with laptops when you have access (through the magic of the Internet) to perfectly good data about the Tesla Roadster? They've been on the road for over four years now.
It says that the batteries have, on average, over 80 percent capacity remaining after 100,000 miles. 80% of the original 265 mile EPA range is still well over 210 miles of range.
Here's the third link from a Google search for "tesla roadster battery degradation" (the first one not written by a "green car" website). http://wallstcheatsheet.com/stocks/tesla-low-balls-roadster-...
It says that the batteries have, on average, over 80 percent capacity remaining after 100,000 miles. 80% of the original 265 mile EPA range is still well over 210 miles of range.