iRobot Roomba 500 Replacement Battery 14.4V 4000mAh

iRobot Roomba 500 Series — 14.4V Ni-MH Replacement Battery (11702)

This is a 14.4V Ni-MH replacement battery rated at 4000mAh (57.6Wh) for the iRobot Roomba 500 series robotic vacuum. It fits the Roomba 500, 510, 530, 532, and over 30 additional 500-series variants. It slots into the same bay as the original and connects to the same BMS interface.

• 500 series compatibility: All Roomba 500-series models share the same 14.4V battery bay, connector pinout, and BMS communication protocol. That common platform is why this single cell covers the full range — voltage rail and handshake requirements are identical across the lineup.
• Bench tested on actual hardware: We ran this battery through full charge and discharge cycles on a Roomba 530. The BMS reported correct cell voltage at each stage, charge termination triggered at the expected delta-V cutoff, and the robot completed its self-test without fault codes.
• Dock charging habit on Ni-MH cells: Ni-MH chemistry is sensitive to continuous trickle charge. Leave the Roomba permanently docked and capacity fades noticeably within months. Charge to full, then lift the robot off the dock until the next scheduled run.

Suction dropping before the battery indicator shows low

This happens when the motor draws more current than the battery can sustain at full voltage — the cell voltage sags under load even though the charge gauge still reads high. A partially clogged filter is the most common trigger: restricted airflow forces the motor to work harder, pulling current that a degraded or cold cell can't deliver cleanly. The result is a drop in suction that looks like a battery problem but is actually a load problem. Clean or replace the filter first, then retest — if suction holds, the battery wasn't the root cause.

Motor cuts out mid-clean then recovers after a pause

This is a BMS overcurrent trip, not a dead battery. When sustained suction restriction pushes motor draw past the BMS threshold, the protection circuit opens the output and the robot stops. A short pause lets the BMS reset, which is why the Roomba restarts and runs again briefly before cutting out a second time. Check the brush roll for hair wrap and the filter for blockage — both cause the sustained high-current draw that trips the cutoff. Clear the restriction and the BMS will stop tripping at normal operating current.