Dyson DC31 22.2V Replacement Battery 17083-2811 5000mAh

Dyson DC31 / DC35 Series — 22.2V Li-ion Replacement Battery (17083-2811)

This is a 22.2V, 5000mAh Li-ion battery for the Dyson DC31, DC34, DC35, and DC44 cordless vacuum range. It replaces the original pack when capacity has faded or the battery no longer holds a usable charge. Cross-references include 18172-01-04, 917083-03, 917083-05, and six additional OEM part numbers.

• DC31 / DC34 / DC35 / DC44 compatibility: These models share the same 22.2V battery platform, connector pinout, and BMS handshake protocol. One battery pack covers all variants in the series without modification.
• Bench tested on actual hardware: We ran this pack through charge cycles on a DC35 unit and monitored BMS response under motor load. Cell balancing engaged correctly across all six cells, and the protection circuit tripped at the expected overcurrent threshold.
• Dock charging habit on DC31 / DC35 models: Do not leave the vacuum sitting on the charging dock continuously. These models trickle-charge when docked and left plugged in — that sustained low-level current accelerates capacity fade. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

On the DC31 and DC35, suction loss before the LED indicator shows a low charge almost always points to voltage sag under motor load — not actual capacity depletion. A worn or partially blocked filter forces the motor to draw above its rated current. The BMS reads that spike and reduces power delivery to protect the cells. Clean or replace the filter first. If suction stabilises after that, the battery was not the fault.

Motor cuts out mid-use and then recovers after a pause

This is a BMS overcurrent trip, not a dead battery. The DC35 motor draws a higher current burst when airflow is restricted — a blocked bin, clogged cyclone, or dirty filter all cause it. The BMS cuts output to protect the cells, and the pack resets once temperature and current drop. Clear the blockage, empty the bin, and check the filter before replacing the battery. If the trip persists on a clean machine, test pack voltage under load — it should hold above 20V.