About this replacement
Xiaomi Mi Robot Vacuum Mop 2 Lite — 14.4V Li-ion Replacement Battery (260V-4S1P)
This is a 14.4V 3350mAh (48.24Wh) Li-ion replacement battery for the Xiaomi Mi Robot Vacuum Mop 2 Lite robotic floor cleaner. It fits models MJSTL, BHR5217EU, and 042621. It replaces OEM part numbers 260V-4S1P and N011-4S1P.
- MJSTL and BHR5217EU compatibility: These model variants share the same 14.4V nominal rail, physical footprint, and BMS communication protocol. The connector pinout and cell arrangement in this 4S1P pack matches the original, so the robot's power management system recognises the replacement without reconfiguration.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the MJSTL platform. The BMS handshake completed correctly, charge termination triggered at the expected cutoff voltage, and the motor draw under load stayed within the overcurrent thresholds without tripping protection.
- Dock charging habit for this robot vacuum: Do not leave the Mi Robot Vacuum Mop 2 Lite sitting on its dock continuously between uses. This model uses a trickle-hold charge when docked at full capacity, which accelerates cell degradation. Charge to full, then remove the robot from the dock until the next cleaning session.
Suction dropping before the battery indicator reaches low
This happens when the motor draws more current than the BMS's sustained-load threshold, usually because the filter is partially blocked. The BMS doesn't shut down — it reduces available current to protect the cells, and the motor slows under the restricted draw. The robot interprets this as normal operation and doesn't flag a battery warning. Clean or replace the filter first; if suction recovers immediately, the battery is not the cause.
Motor cuts out mid-clean then restarts on its own
This is a BMS overcurrent trip, not a battery failure. When the suction path is restricted — blocked brush roll, clogged filter, or a tight corner sustained at full suction — current spikes above the trip threshold and the BMS briefly disconnects the output. The robot pauses, the BMS resets, and power restores. Clear the brush roll and filter, then run a cleaning cycle. If the cutout stops, the replacement battery is functioning correctly and the fault was draw-side, not supply-side.