Dyson DC61 21.6V Replacement Battery 965874-02 5000mAh

Dyson DC61 / DC62 Series — 21.6V Li-ion 5000mAh Replacement Battery (965874-02)

This 21.6V 5000mAh lithium-ion battery replaces the original pack on the Dyson DC61, DC62, DC58, DC62 Animal, and over 30 related cordless stick vacuum models. It carries OEM part numbers 965874-02, 965874-01, 965874-03, 967810-02, and several others in the same family. Capacity is rated at 108Wh — matching the original specification from the product data.

• DC61 / DC62 battery family: These models share a common 21.6V cell architecture, connector pinout, and BMS handshake protocol. A battery built for DC61 communicates correctly with the DC62 and DC58 motor controllers without modification — the voltage rail and BMS signal lines are identical across this generation.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a DC62 unit. The BMS engaged correctly at low-voltage cutoff, held charge termination at the expected threshold, and the motor controller accepted the pack without fault codes or LED error sequences.
• Dock charging on Dyson stick vacuums: Do not leave this vacuum on the dock permanently. Dyson's wall-mount dock does not switch to a true maintenance mode — extended dock time pushes a continuous low-level charge into the cells. Charge to full, then remove the machine from the dock until the next use.

Cordless vacuum losing suction before the battery indicator reaches low

The DC61 and DC62 motor controller regulates power based on both battery state and motor load. When the filter is partially blocked, the motor draws higher current to maintain airflow — the BMS reads this as elevated discharge and steps the output voltage down before the LED indicator signals low battery. The vacuum feels like it's losing suction, but the battery indicator still shows green or amber. Clean or replace the filter first and retest; if suction recovers immediately, the battery was not the fault.

Motor cuts out briefly then restarts on its own

This is a BMS overcurrent trip, not a failed motor. Under sustained restricted airflow — typically a blocked cyclone inlet or a heavily loaded carpet pass — current draw spikes past the BMS protection threshold and the pack temporarily disconnects the output. The BMS resets automatically within a few seconds, which is why the motor restarts without any user input. Clear the blockage and check that the filter is seated correctly. If the trip repeats on an unblocked machine, verify the pack voltage under load sits above 19.5V; a cell group dropping below that point under draw indicates cell degradation.