Charging is limited by two factors: - the power you can get from the charger to the batteries - the power the cells can accept You can reasonably easily fix t

Charging is limited by two factors: - the power you can get from the charger to the batteries - the power the cells can accept You can reasonably easily fix the first point with custom infrastructure, so the second point will be the limiting factor, and that one means that it always takes e.g. 20 minutes to charge your batteries, regardless how many you're charging (because with a bigger battery, you're simply charging more cells in parallel, at the same speed per cell).