AI-Vacuum Lithium-ion 4400 mAH Battery for Roomba 500, 600,700, 800 Series 4x longer battery life than iRobot Roomba batteries and all aftermarket replacement batteries. 800 cycle times, 1 Lithium-ion = 4 NiMH/NiCd batteries Longer operating time! 4400 mAH vs original battery's 3000 mAH. We guarantee this Li-ion battery has superior performance than any NiMH battery in market No risk 30 days money back guarantee, and 18 month warranty. FULLY compatible with the original charger and vacuum. Built-in over-charge, over-discharge, over-voltage, over-current, and over-temperature protection circuit.