And you've got to engineer for its safety. Most batteries are in highly firewalled (in the physical sense of walls made to keep fire from spreading in the batte

And you've got to engineer for its safety. Most batteries are in highly firewalled (in the physical sense of walls made to keep fire from spreading in the battery), structurally intense places in an EV (often in current "skateboard" designs the battery helps make up the literal foundations of the car). Making them removable adds safety tradeoffs (weaker firewalls so that they can be opened/closed for battery removal operations; among other structural trade-offs).