Xiaomi Mi Robot Vacuum BHR5055EU 14.4V Replacement Battery

Xiaomi Mi Robot Vacuum Mop 2 — 14.4V Li-ion Replacement Battery (P2051-4S1P-ZM)

This is a 14.4V, 2600mAh Li-ion replacement battery for the Xiaomi Mi Robot Vacuum Mop 2 and related models. It fits the BHR5055EU and STYTJ03ZHM variants using OEM part number P2051-4S1P-ZM. Swap it in when the original cell no longer holds enough charge to complete a cleaning cycle.

• BHR5055EU, Mi Robot Vacuum Mop 2, STYTJ03ZHM compatibility: All three models run the same 14.4V P2051-4S1P-ZM battery format with an identical 4S1P cell arrangement and BMS connector pinout — one replacement covers all.
• Bench tested on actual hardware: We ran this battery through full charge and discharge cycles on the Mi Robot Vacuum Mop 2. The BMS handshake completed without fault codes, and the dock recognised the cell correctly on first dock contact.
• Dock charging habit for this robot vacuum: Do not leave the robot on its dock permanently between uses. The Mi Robot Vacuum Mop series uses a trickle-top-up charge when docked continuously, which accelerates capacity fade. Charge to full, then remove it from the dock until the next scheduled run.

Suction dropping before the battery indicator reaches low

The Mi Robot Vacuum Mop 2 runs its brushroll and suction motor from the same 14.4V rail. When the filter is partially blocked, the motor draws above its rated current to maintain airflow. That elevated draw causes voltage sag at the cell terminals — the BMS reads it as low voltage and scales back motor power, which the robot reports as weakening suction even though the indicator still shows mid-charge. Clean or replace the HEPA filter first. If suction recovers after a filter clean, the battery is not the cause.

Robot powers off mid-cycle and restarts after a short pause

This is a BMS overcurrent trip, not a battery failure. A restricted filter or tangled brushroll forces the motor to spike current beyond what the BMS allows, triggering a protective shutdown. The cell cools, voltage recovers, and the robot restarts — repeating the cycle. Clear any brushroll obstruction, then check the filter. If the cutout stops after clearing the restriction, the replacement cell is functioning correctly. If it continues with a clean filter and clear brushroll, verify cell voltage at the dock contact points — it should read between 15.6V and 16.8V on a full charge.