Thank you for your question @Andreas95. With the Roomba i7 you can create up to 10 maps, e.g. 1 map per floor. The base does not have to be moved, the Roomba simply ends its journey without a base where it was started. However, there are customers who buy a second charging station, definitely not a must :)

Yes, you can.
i7 can memorise several maps and then recognises which floor it is on.
It doesn't need a charging station for cleaning. You can simply carry it down/up at the end to charge it.