Robotic U290 Ni-MH Replacement Battery 14.4V 4000mAh

Robotic U290 — 14.4V Ni-MH Replacement Battery

This is a 14.4V, 4000mAh Ni-MH battery pack for the Robotic U290 robotic vacuum cleaner. It replaces the original pack when capacity has faded and the vacuum can no longer complete a full cleaning cycle. Voltage and connector match the U290's onboard charging circuit and motor controller.

• U290 platform fit: The U290 runs a 14.4V motor rail with a Ni-MH pack wired to the onboard BMS. This replacement matches that voltage and cell count, so the charge controller reads pack state correctly and the motor draws at the rated current without triggering low-voltage cutoff early.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the U290 platform. The BMS completed full charge acceptance, transitioned to standby cleanly, and the motor sustained load through a full cleaning pass without a mid-cycle cutoff event.
• Dock charging habit on the U290: Do not leave the U290 on the charging dock continuously between uses. Ni-MH cells in this pack degrade faster under sustained trickle charge than from regular full discharge and recharge cycles. Charge to full, then remove from the dock until the next use.

Suction dropping before the battery indicator reaches low on the U290

This happens when the motor is working harder than rated — usually because a partially blocked filter forces increased draw. The extra current pulls cell voltage down faster than the indicator circuit expects, so the pack appears to die early. The indicator is calibrated for a clean filter and normal motor load. Check and clean the filter before concluding the battery is at fault — a clear filter restores normal voltage curve behaviour.

U290 motor cutting out mid-run and then recovering after a short pause

This is a BMS overcurrent trip, not a dead battery. When sustained suction restriction — blocked brush roll, clogged filter, or debris jam — pushes motor current above the BMS threshold, the pack shuts the output to protect the cells. After the cells cool and current demand drops, the BMS resets and the motor starts again. Clear the blockage, confirm the brush roll spins freely, and verify the filter is clean. If the trip continues with no restriction present, check pack voltage under load — it should hold above 13.0V during normal motor start.