Henxlco 14.4V APS Vacuum Battery for iRobot Roomba 500 530 510 550 560 570 540 R3 Series Cell Type: Ni-CD; Voltage:14.4 V; Capacity: 2500mAh 14.4V APS Vacuum Battery for iRobot Roomba 500 530 510 550 560 570 540 R3 Series Notice 1: Discharge them as much as possible first. DO NOT full charge your batteries before storing them for long periods of time. Notice 2: Please fully cycle your batteries (fully charge, then fully discharge them) at least TWICE before regular use. It just needed to be charged and discharged a few times in order to reach its full potential. Notice 3: Please FULLY charge your rechargeable batteries before first use. When in doubt, charge your batteries overnight (8 hours).