See here for battery installation size - 69.0 kWh per NEV (up 27.9% YoY). 64.2 for BEV & 41.2 for PHEV pax vehicles, remaining growth down to much higher trucking electrification)
Avg truck 217 kWh, coach 213.4 kWh, PV 56.5 kWh so far in 2026.
System wide battery Density has shifted w/ center around 140-160 Wh/kg
Again, the big factor is actually not the energy density change but higher charge/discharge speed + lower cost.