iRobot iRobot Roomba i3 EVO (3150) Auto Charging Robotic Vacuum in the Robotic Vacuums department at Lowes.com
Compatible with Roomba Battery Accessory Ni-MH 3.5 AH Battery and Accessory Part Kit 500 Series 500 510 520 530 531 535 536 540 545 550 a Set of 10 - Walmart.com