About this replacement
Electrolux EFP61712 Series — 21.6V Li-ion Replacement Battery (WKZS21625PG-25)
This 21.6V lithium-ion battery at 2500mAh (54Wh) replaces the original WKZS21625PG-25 pack in Electrolux cordless stick vacuums. It fits the EFP61712, EFP61712A, EFP61713, and EFP61714 models. When the original pack can no longer hold charge through a full cleaning pass, this replacement restores the motor's working voltage range.
- EFP61712 series compatibility: These four models share the same 21.6V nominal voltage rail, connector format, and BMS handshake protocol. Swapping between them carries no compatibility risk — the cell chemistry and communication signals match across the range.
- Bench tested on actual hardware: We ran this pack through charge cycles and confirmed the BMS correctly limits inrush current at motor start, holds voltage under sustained suction load, and triggers thermal cutoff within spec range before the housing reaches unsafe temperatures.
- Dock charging habit on EFP61712 vacuums: Do not leave this vacuum sitting on the charging dock indefinitely. The EFP series dock does not interrupt charge once the pack is full — it continues trickle charging, which accelerates capacity fade in Li-ion cells. Charge to full, then remove the vacuum from the dock.
Suction dropping before the battery indicator reaches low on EFP61712
A partially blocked filter or cyclone chamber forces the motor to draw current well above its rated load. The BMS reads this as a high-drain event and steps down voltage delivery to protect the cells — suction drops noticeably even though the indicator still shows charge remaining. The vacuum is not failing; the battery is responding correctly to an overloaded motor. Clean the filter first. If suction restores immediately after cleaning, the battery was never the issue.
Motor cuts out mid-clean and then recovers after a short pause
This pattern is a BMS overcurrent trip, not a dead battery. When sustained suction restriction — from a clogged filter, tangled brush roll, or blockage in the duct — forces continuous high current draw, the BMS trips and disconnects the motor to prevent cell damage. After a brief pause, internal temperature drops and the BMS resets, which is why the vacuum powers back on. Clear any blockage, confirm the filter is clean and fully seated, then restart. If the trip repeats with a clean filter, measure resting voltage — a healthy pack at partial charge should read above 20V.