Amazon.com: SPARKOLE 5300mAh Extended Life Lithium Ion Battery Compatible with iRobot Roomba 500 600 700 800 Series 880 770 650 655 870 760 780 790 645 595 585 561 560 550 531 861 864 866 775 780 : Home & Kitchen
Customized 5200mAh 14V Rechargeable Lithium Battery for Irobot Roomba 500 600 700 Series 14V Lithium Ion Battery with CE /Un38.3/ IEC62133/MSDS - China Lithium Battery, LiFePO4 Battery | Made-in-China.com