Henxlco 14.4V Battery for iRobot Roomba APC 400 405 410 415 416 418 4905 4000 Series Battery Type: Ni-CD; Capacity: 2500mAh ; voltage: 14.4 V For iRobot Roomba Vacuum Battery APC 400 SERIES 4905 4000 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).