Running time / charge (minutes) 60minutes Charging time (max. in min.) 180minutes Smallest crumbs, fine hairs, but also somewhat larger dirt particles are sucked up very reliably. http://www.staubsauger-berater.de/saug-roboter/irobot-roomba-615-staubsaug-roboter-einstiegsmodell-test/ http://www.akku-und-roboter-staubsauger.de/irobot-roomba-615-616-620-600er-serie-test-vergleich/

Until the battery is empty, then it drives back to the base. You can also send it back by pressing a button.

The 615 overcomes thresholds up to approx. 20mm. Up to approx. 30mm can be helped with an auxiliary ramp (approx. 30°-40°). It cannot manage 5cm.

The width is not a problem. The more important question is how high is the door threshold?