iMartine C800 Replacement Battery 14.4V 2600mAh Li-ion

iMartine C800 / D900C — 14.4V Li-ion Replacement Battery (CMICR18650F8M7-4S1P)

This is a 14.4V 2600mAh Li-ion battery pack for the iMartine C800 and D900C cordless stick vacuums. It replaces the original pack when capacity has degraded from repeated charge cycles. Voltage, connector, and BMS communication match the factory specification on both models.

• C800 and D900C compatibility: Both models run the same 14.4V motor rail and use the same pack form factor and connector pinout. The BMS handshake protocol is identical across the two, so one pack covers either unit without modification.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the C800 motor platform. The BMS held the 14.4V rail steady under sustained suction load and tripped correctly at the low-cell threshold before the motor saw damaging undervoltage.
• Dock charging behaviour on these vacuums: Do not leave the C800 or D900C sitting on the charging dock continuously. These vacuums trickle-charge when docked and the pack degrades significantly faster under constant top-up current. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

On the C800, suction can fall noticeably while the indicator still shows two or three bars. This is voltage sag — the pack is delivering less than the motor needs under load, even though the resting cell voltage reads as acceptable. A degraded or ageing pack loses the ability to sustain current under the draw of a partially blocked filter. If cleaning bare floors does not trigger it but carpet does, restricted airflow is amplifying the draw and exposing the sag earlier.

Motor cuts out mid-clean then recovers after a few seconds

This is a BMS overcurrent trip, not a fault with the motor itself. When suction airflow is restricted — a full dustbin, a clogged filter, or a blocked brush roll — the motor works harder and pulls more current than the BMS allows. The BMS cuts power to protect the cells, waits for current demand to drop, then restores it. Clear the filter and empty the bin first. If cut-outs stop, the pack is fine. If they continue on an unblocked vacuum, check that the replacement pack's BMS current rating matches the original at 14.4V.