Botvac Connected comes with a long lasting Li-Ion rechargeable battery. We recommend that you do an initial charge overnight and then make sure that you keep the robot on its charge base in between cleanings. As with all rechargeable batteries, the battery will deteriorate over time and at some point in the future it will need replacing. The life of your battery depends on how frequent you vacuum and the environment your Neato cleans. NOTE: The Neato Li-Ion battery is only compatible with Botvac Connected robots.