Yes. The person I was replying to thought it was somehow bad for the battery to outlast the car. I was making the point that that's fine. In response to your point about the cost of an engine, I should say that batteries are a far bigger part of the cost of an electric car - it's really just not very complicated apart from that - very few moving parts indeed compared to a combustion engine. That's why the car companies aren't very keen - unless they make their own batteries, they're not adding as much value when they manufacture them. They prefer to push the hybrids which have the complexity of both and a lot less battery capacity (but very much don't have the advantages of both for the driver).