I would imagine that the difficulty in charging is proportional to the cell's capacity, so charging 2*n cell shouldn't be any harder than charging n cells, as l

I would imagine that the difficulty in charging is proportional to the cell's capacity, so charging 2*n cell shouldn't be any harder than charging n cells, as long as the cell's capacity is the same. If you increase the capacity of a cell, then you might have to innovate.