XRobot M-788 Replacement Battery 14.4V 2000mAh Ni-MH

XRobot M-788 — 14.4V Ni-MH Replacement Battery

This is a 14.4V 2000mAh Ni-MH replacement battery for the XRobot M-788 robotic vacuum cleaner. It slots into the M-788 to restore cordless autonomous floor cleaning after the original cell loses capacity or fails. Voltage and capacity match the original specification exactly.

• M-788 platform fitment: The M-788 runs a 14.4V motor rail with a Ni-MH pack sized to the 179 × 51 × 52 mm bay. This cell matches those dimensions and the voltage the drive motors and navigation board expect. A mismatch in either drops the BMS handshake and the unit will not initialise.
• Bench tested on actual hardware: We cycled this cell through full discharge and recharge sequences on M-788 hardware. The BMS accepted the pack without fault codes, the suction motor ramped to full speed, and charge termination triggered cleanly at capacity.
• Dock charging habit for Ni-MH cells: Remove the vacuum from the charging dock once the charge cycle completes. Ni-MH chemistry is more sensitive to trickle overcharge than Li-ion. Leaving the M-788 docked permanently accelerates cell degradation faster than regular charge-and-remove cycles.

Suction dropping before the battery indicator reaches low on the M-788

This happens when the motor draws more current than the cell can sustain at its present state of charge. A partially blocked filter forces the motor to work harder, pulling current above the BMS threshold and triggering a voltage sag before the indicator registers a low state. The vacuum reads cell voltage, not remaining energy, so the indicator lags behind real-world performance. Clear the filter first — if suction still drops early with a clean filter, the cell has aged below usable capacity and needs replacement.

M-788 motor cuts out mid-cycle then recovers after a few seconds

This is a BMS overcurrent trip, not a motor fault. Sustained restricted airflow — usually a clogged filter or brush roll tangle — pushes motor current above the pack's protection threshold. The BMS disconnects the load, the motor stops, and reconnects once current demand resets. Fix the restriction first: remove the filter, clean it, and check the brush roll for hair wrap. If the cutout continues on a clear filter, measure pack voltage under load — a healthy 14.4V Ni-MH cell should hold above 12.5V during normal suction operation.