About this replacement
Bissell PowerClean FurFinder 4239 — 25.2V Li-ion Replacement Battery (1643447)
This is a 25.2V 2000mAh (50.4Wh) lithium-ion replacement battery for the Bissell PowerClean FurFinder 4239 and FurGuard series cordless vacuums. It replaces OEM part numbers 1643447, 1643449, 1644206, and 1644207. It fits the FurFinder 4239, FurGuard 200W, FurGuard 280W, and FurGuard 4241, among other models in this series.
- FurFinder and FurGuard series fit: These models share the same 25.2V power rail, physical battery bay dimensions, and BMS handshake protocol. Swapping between them does not require any configuration — the connector and BMS communication are identical across the range.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the FurGuard 280W platform. The BMS held the 25.2V rail stable under carpet-level motor load and triggered cutoff correctly at low-voltage threshold without nuisance tripping under normal use.
- Dock charging on these vacuums: Remove the vacuum from the charging dock once the battery reaches full. Leaving a Bissell FurFinder or FurGuard on continuous dock charge accelerates capacity fade — the trickle current these docks maintain degrades lithium cells faster than a standard charge-and-remove cycle.
Suction dropping before the battery indicator shows low
On the FurFinder 4239 and FurGuard models, suction loss often happens before the battery LED changes state. The motor draws harder when the filter is partially blocked, pulling more current than the cell is rated to sustain at full speed. This causes voltage sag at the motor — suction drops, but the battery indicator still reads mid-range because overall charge isn't depleted. Check and clean the filter first. If suction recovers immediately after cleaning, the battery is not the issue.
Motor cuts out mid-clean then restarts after a pause
This is a BMS overcurrent trip, not a dead battery. When the vacuum runs against a heavy blockage or a clogged filter, the motor's current draw spikes above the BMS threshold — the BMS shuts the cell off to protect the lithium pack. After 30–60 seconds, the BMS resets and the vacuum powers on again. Clear any blockage, clean the filter, and check that the exhaust vent is unobstructed. If trips continue on a clear filter, measure resting cell voltage — a healthy 25.2V pack should read between 25.0V and 26.1V after a full charge.