These are 2 different things; "better batteries" is scientific and engineering breakthroughs. Engineering in the sense of building them in on time, in quantity,

These are 2 different things; "better batteries" is scientific and engineering breakthroughs. Engineering in the sense of building them in on time, in quantity, to quality and on a budget. "Better charging networks" is infrastructure rollout that is underway. If it's an engineering issue, it's civil engineering. Charging networks are on the whole continually getting better. But maybe not at a fast enough pace. Both can happen, though. Both would make a difference.