iRobot Roomba 400 Replacement Battery 14.4V 4000mAh

iRobot Roomba 400 Series — 14.4V Ni-MH Replacement Battery (11700 / 17373)

This 14.4V 4000mAh Ni-MH battery replaces the original power cell in the iRobot Roomba 400 series robotic vacuum. It fits the Roomba 400, 4000, 4905, APS 4905, and over two dozen additional 400-series variants. Voltage and capacity match the factory specification exactly.

• 400-series platform fit: All Roomba 400-series units share the same 14.4V battery bay, connector pin-out, and BMS communication protocol. One cell covers the full range of models listed, because iRobot held those specs constant across the entire 400 platform.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Roomba 400-series unit. The BMS handshake completed without fault codes, the motor and navigation systems drew current normally, and the protection circuit held cutoff at the correct low-voltage threshold.
• Dock charging discipline on the Roomba 400: The Roomba 400 trickle-charges indefinitely when left on the dock between uses. Ni-MH cells degrade faster under continuous trickle charge than under regular full cycle use. Charge to full, remove from the dock, and store the robot off the base when not in daily use.

Suction dropping before the battery indicator reaches low

The Roomba 400's motor draws significantly more current when airflow is restricted — a clogged filter or partial blockage can push draw well above the rated operating load. When current spikes, voltage sags earlier in the discharge curve, and suction noticeably weakens before the low-battery indicator triggers. This is a motor voltage-sag symptom, not a defective battery. Clean or replace the filter first, then run the unit again to confirm whether suction holds across the full cycle.

Roomba 400 cutting out mid-clean and then recovering after a pause

A mid-clean cutout followed by recovery after a short rest is a BMS overcurrent trip, not a dead battery. The protection circuit interrupts discharge when sustained current exceeds its threshold — typically triggered by a blocked brush roll or restricted airflow forcing the motor to labour. The cell cools slightly during the rest period, the BMS resets, and the robot powers back on. Clear the brush roll and filter before the next run, and check that the battery resting voltage reads at least 14.0V after recovery.