All I can say is... Wow! I'm guessing this means their cell testing/assembly/diagnostics, chemistry, and BMS. Tesla battery research partner working on longevity breakthrough says work is going into the company’s products As far as I know, and I'm a layperson, Jeff Dahn is at the cutting edge of battery capacity loss/longevity. The Model 3 may be the first car sold with battery packs that can consistently go decades/several hundred thousand miles without replacement. In that context, Tesla's stock price makes sense, as does the Solar City acquisition, since any battery improvements would also go into the powerwall and in many cases bring the costs of off-grid renewable electricity (solar/wind + storage) in line with electricity from the grid.