same old thing
I'll believe it when I see it, otherwise it's all claptrap. And I want to see how much of that 400 miles can be done in Texas in the 107 deg. F Summer with the air conditioning on high, otherwise the claims are no more than "hot air".
That is one point the purveyors of electrics always hide, the comfort penalty, and if the vhicle has a/c, they never disclose the BTU rating of it because people would then see that it is very small system.
For those in cool climates, the same thing applies to the heater, but it can be supplimented by vehicle waste heat so it is less of an issue.
For these reasons, which really relate to the usefulness and desirability of a vehicle, I hope the new battery works as claimed.