BATTERIES ARE BULKY AND HEAVY and no one wants that. Worse, a lot of that excess stems not from the actual cells that store the electricity, but from structures designed to house and cool them.
EVs use individual cells, wired in series to reach the approx 400V or even 800V that the drive systems use. Standard procedure is to package a number of cells, maybe two dozen, into a structure called a module. This is basically a metal box, incorporating wiring between the cells, and cooling channels. Multiple modules are fixed inside a bigger, stronger box. The battery pack.
This sounds safe. The cells are mounted in three layers of box. If one group of cells fails, only that module needs replacing not the whole pack. But it's also wasteful.…
