About this replacement
Dyson DC31 / DC35 / DC44 Series — 22.2V Li-ion Replacement Battery (17083-2811)
This is a 22.2V, 2000mAh lithium-ion battery for Dyson DC31, DC34, DC35, and DC44 cordless handheld and stick vacuums. It replaces OEM part numbers 17083-2811, 18172-01-04, 17083-4211, 18172-0201, 917083-03, 917083-05, 17083-5010, and 17083-3009. Capacity is 44.4Wh, matching the original cell specification.
- DC31, DC34, DC35, DC44 compatibility: These models share the same 22.2V battery rail, connector housing, and BMS communication protocol. One cell pack covers all four platforms without modification to the battery bay or charge contacts.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a DC35 unit. The BMS accepted the Dyson charger handshake on first connection, cell balancing engaged correctly across all six cells, and overcurrent protection triggered as expected under a simulated blockage event.
- Dock charging habit on DC31 and DC35: Do not leave these vacuums sitting on the charging dock indefinitely. Continuous dock charging applies a low trickle current that degrades cell capacity faster than cycling the pack normally. Charge to full, then remove from the dock until the next use.
Suction dropping before the battery indicator reaches low
The DC31 and DC35 motors draw significantly more current when airflow is restricted — a partially blocked filter can push draw well above the BMS's sustained-current threshold. The BMS responds by reducing power delivery to protect the cells, which the user experiences as suction loss even with charge remaining. This is not a battery fault. Clean or replace the filter and the motor will return to full draw at the same state of charge.
Motor cuts out mid-use and then recovers after a short pause
This is a BMS overcurrent trip, not a failing battery. When the motor encounters sustained restriction — a blocked nozzle, a clogged cyclone, or a choked filter — current spikes beyond the pack's trip threshold and the BMS shuts output. After 30–60 seconds the BMS resets and power returns. Clear the blockage before the next run. If trips continue on an unblocked machine, charge the pack to full (22.2V at the terminals) and retest — a partially discharged cell can lower the trip threshold.