iRobot Roomba 400 Replacement Battery 14.4V 3000mAh 11700

iRobot Roomba 400 Series — 14.4V Ni-MH Replacement Battery (11700)

This is a 14.4V 3000mAh Ni-MH replacement battery for the iRobot Roomba 400 series robotic vacuum. It fits the Roomba 400, 4000, 4905, APS 4905, and over two dozen additional models in the same family. Physical dimensions are 179 x 51 x 52mm — match these against your existing battery before ordering.

• Roomba 400 family compatibility: Every model in this range runs the same 14.4V battery architecture with an identical connector footprint and BMS communication protocol. That is why one part number covers 30-plus variants without modification.
• Bench tested on actual hardware: We cycled this cell through the Roomba's charge and discharge sequence and monitored BMS handshake behaviour. The battery accepted the onboard charger signal without fault and discharged within expected voltage curves for Ni-MH at this capacity.
• Dock charging behaviour on Roomba 400: Do not leave the Roomba sitting on the home base continuously. The 400 series dock does not cut trickle charge once the battery is full. Leaving it docked between every use accelerates capacity fade. Charge when depleted, then remove from the dock until the next session.

Suction dropping before the battery indicator reaches low

Ni-MH cells have a relatively flat discharge curve until voltage collapses quickly near depletion. On the Roomba 400, suction loss that appears early is rarely a battery fault — the motor is pulling higher current than rated because airflow is restricted. A clogged filter raises motor load, which causes voltage sag across the cell pack before state-of-charge is actually low. Clean the filter first and retest before concluding the battery is at fault.

Motor cuts out mid-clean and then recovers after a pause

This is a BMS overcurrent trip, not a failed battery. When the Roomba drives into heavy carpet or a partial blockage, the motor draws a sustained current spike. The BMS reads this as an overcurrent event and opens the circuit to protect the cells. After a short rest, the BMS resets and the robot runs again. Clear any brush-roll blockage and check the filter. If the cutout repeats on open floor with a clean filter, measure resting pack voltage — it should sit above 15V fully charged on a 14.4V Ni-MH pack.