Dyson DC61 21.6V Replacement Battery 965874-02

Dyson DC61 / DC62 Series — 21.6V Li-ion Replacement Battery (965874-02)

This 21.6V 2500mAh (54Wh) lithium-ion battery replaces the factory cell in the Dyson DC61, DC62, DC58, DC62 Animal, and over 30 additional Dyson cordless stick vacuum models. It uses OEM part numbers 965874-02, 205794-01/04, 967810-02, and related variants. When the original cell loses capacity after repeated charge cycles, this replacement restores the motor to its rated operating voltage.

• DC61 / DC62 platform compatibility: These models share a common 21.6V battery rail, connector format, and BMS communication protocol. A single cell design covers the full range because Dyson kept the power architecture consistent across this vacuum generation.
• Bench tested on actual hardware: We ran this battery through charge and discharge cycles on a DC62 motor unit. The BMS held the 21.6V rail stable under sustained motor load and triggered overcurrent protection correctly when the suction path was deliberately blocked.
• Dock charging habit on DC61 / DC62 vacuums: Do not leave the vacuum sitting on the charging dock permanently. These vacuums draw a trickle charge continuously when docked, which accelerates capacity fade in the lithium cells. Charge to full, then remove the vacuum from the dock between uses.

Cordless vacuum losing suction before the battery indicator reaches low

This happens when the motor draws more current than the BMS expects — usually caused by a partially blocked filter or a restricted suction path, not a failing battery. The motor works harder against the blockage, voltage sag increases, and the BMS reads an apparent low-power condition before the cell is actually depleted. Wash the filter and let it dry for 24 hours before concluding the battery is at fault. If suction recovers after a clean filter, the cell is fine.

Motor cuts out mid-clean and restarts after a few seconds

This is a BMS overcurrent trip, not a dead battery. When sustained restricted airflow forces the motor to pull above its rated current, the BMS cuts power to protect the cell, then resets once the surge clears. It will keep happening if the restriction is still there. Check the bin, the filter, and the inlet path for blockages — clear the restriction and the cutouts stop. If the motor still trips on an unobstructed path, measure the pack voltage under load; it should hold above 18V.