About this replacement
Dyson DC30 / DC35 Series — 22.2V Li-ion Replacement Battery (967813-03)
This is a 22.2V, 2500mAh lithium-ion battery for the Dyson DC30, DC31, DC34, and DC35 cordless handheld vacuums. It replaces OEM part 967813-03 directly. Use it when the original cell no longer sustains suction through a full cleaning cycle.
- DC30 / DC31 / DC34 / DC35 compatibility: These four models share the same 22.2V battery rail, connector pinout, and BMS communication protocol — that is why one cell fits all of them. Voltage and physical form factor are identical across the range.
- Bench tested on actual hardware: We ran this cell on a DC35 under motor load. The BMS held steady through repeated full-suction cycles, with no overcurrent trips or thermal shutdowns recorded at normal operating draw.
- Dock charging habit for DC30 / DC35: Do not leave the vacuum sitting on the charging dock continuously. These vacuums trickle-charge when left docked permanently, and that sustained low-current charge accelerates capacity loss. Charge fully and remove the unit from the dock.
Suction dropping before the battery indicator reaches low
This happens when the motor draws more current than the BMS expects — usually because a partially blocked filter forces the motor to work harder. The BMS reads this as a voltage sag and begins throttling output before the indicator registers low. The cell is not always the cause. Clean or replace the filter first, then retest suction across a full cycle to confirm whether the battery itself is degraded.
Motor cutting out mid-clean and then recovering after a few seconds
This is a BMS overcurrent trip, not a dead battery. When airflow is restricted — blocked filter, clogged cyclone, or a blockage in the bin — the motor draws a spike of current that crosses the BMS cutoff threshold. The BMS shuts the motor down to protect the cell, then resets after a short pause. Clear any blockage, clean the filter, and run again. If the cut-outs continue with a clean, unblocked machine, measure pack voltage at rest — a healthy cell at this capacity should read 24.5–25.2V after a full charge.