iRobot Roomba Series 500, 600, 700, 800, and R3 Battery
Vacuum Battery For iRobot Roomba 4000 Discovery / Dirt Dog - 2 Pack - Walmart.com
Amazon.com: iRobot Roomba Authentic Replacement Parts - XLife Extended Life Battery - Compatible with Roomba 400 600 700 800 Series Robots : Home & Kitchen