According to iRobot, the Roomba’s battery can generally be used for about two hours after each charging session. They also say that their battery can be charged up to 400 times. Essentially, that equates to an average of 2 to 4 years of efficient service. It’s also important to note that proper maintenance and service will prolong the lifespan of your Roomba. Change the filters every 2 to 3 months and follow all other maintenance instructions supplied by the manufacturer. Another recommendation is to keep the Roomba plugged in when it's not being used. This will extend the battery life.