You are correct. The max charging rate of the battery is independent of its voltage, and runs around 2.4 C (Tesla) to 2.8 C (Porsche). You only get this max rat

You are correct. The max charging rate of the battery is independent of its voltage, and runs around 2.4 C (Tesla) to 2.8 C (Porsche). You only get this max rate for the first 20% or so of SOC (state of charge). One way to think about this is that each individual cell has a nominal voltage around 3.7, and doesn't care how it's wired into the battery. The confusion arises because a given DC charger can deliver twice as much power at 800 volts as it can at 400, assuming it's running at its max current. But that's a limitation of the charger, not the battery. This article has a brief discussion: https://insideevs.com/news/512344/porsche-taycan-fast-charging-analysis/ https://insideevs.com/news/512344/porsche-taycan-fast-chargi... [ I used to work for a car company, programming battery charge controllers among other things ]