A Roomba battery runs for a maximum of 2 hours and it is estimated to last up to 400 charges, which is excellent. The number of years cannot be determined because the lifespan is based on how often you charge it. Additionally, you should take proper care of it otherwise you will need to replace it sooner. Therefore, when you are planning to buy a Roomba robot vacuum cleaner, make sure to read about everything about it first, especially the care instructions. That is where you will find information on how to properly take care of your Roomba battery.