I'm wondering about dynamic stresses. Will the "cast pan, steel cans, and epoxy" be ridiculously strong? yes ... but that's a lot of random forces hitting it for a million miles, so have to expect some amount of bending/cracking. Also, the cobalt-free chemistry complained of a 4x volume change between charged & discharged ... yeah there's a flexible polymer casing on the powdered anode, but still that seems a lot of flexing of a lot of cells over a long time. Maybe it all adds up to more durable than I expect; a million miles on a truck is a lot of kinetic energy. Convince me please.