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 3200mAh Li-ion battery that replaces the original P2051-4S1P-ZM cell pack in the Xiaomi Mi Robot Vacuum Mop 2 (BHR5055EU / STYTJ03ZHM). It restores full operation when the original pack no longer holds a charge or triggers a low-battery shutdown before completing a cleaning cycle. Capacity matches OEM spec at 46.08Wh.

• BHR5055EU / STYTJ03ZHM platform fit: These three model numbers share the same 14.4V battery bay, the same P2051-4S1P-ZM connector format, and the same BMS handshake protocol. A single cell pack covers all three without any modification.
• Bench tested on actual hardware: We cycled this pack through a full charge and discharge sequence on the BHR5055EU chassis. The BMS accepted the charge signal immediately, cell balancing completed normally, and the vacuum returned a full status indicator on the dock before the first cleaning run.
• Dock charging behaviour on the Mi Robot Mop 2: Do not leave this vacuum parked on the dock permanently between uses. The Mi Robot Mop 2 does not interrupt trickle current when the pack is at 100%. Continuous dock contact causes measurable capacity fade over a few months. Charge to full, then remove from the dock until the next scheduled run.

Suction dropping before the battery indicator reaches low

When a degraded cell pack loses capacity, the 14.4V rail sags under motor load before the fuel gauge registers critical. The vacuum's suction motor draws peak current on thick carpet or when debris partially blocks the intake — that sudden load spike drops pack voltage fast enough that the motor throttles back, even though the indicator still shows two or three bars. A new pack with healthy internal resistance holds the voltage rail steady under the same load. If you see suction drop early on a new battery, check the filter first — a clogged filter forces the motor to work harder and pulls more current than the BMS expects at that state of charge.

Robot vacuum cuts out mid-run and resumes after sitting idle

This is a BMS overcurrent trip, not a dead battery. When the intake is restricted — by a blocked filter, tangled brush roll, or a rug fringe caught in the path — the motor draws sustained current above the pack's rated threshold. The BMS cuts power to protect the cells, the robot stops, and after a short recovery window it resumes because the overcurrent condition cleared. Replacing the battery does not fix this if the restriction is still present. Clean the filter, clear the brush roll, and run a short test cycle. If the trip does not repeat, the pack was protecting itself correctly. If it persists on a clean machine, check that the replacement pack voltage reads at least 16.0V fully charged before reinstalling.