Bosch BHN24L 21.6V Cordless Vacuum Replacement Battery 3500mAh

Bosch BHN24L Series — 21.6V Li-ion Replacement Battery (801BPV216-01)

This 21.6V 3500mAh Li-ion battery replaces the original pack in the Bosch BHN24L cordless handheld vacuum and related models including the BHN24L/04, Move Lithium 24V Max, and VXAS002V21. It matches the OEM voltage rail and BMS handshake the charger expects. Swap it in when your original pack no longer holds charge or suction has dropped off noticeably even with a clean filter.

• BHN24L platform fit: The BHN24L series shares a common 21.6V cell configuration and connector across its variants. The BMS in each of these models communicates the same handshake signal to the charger, so one replacement cell covers the full range without modification.
• Bench tested on actual hardware: We ran this pack through charge cycles on the BHN24L platform and confirmed the BMS negotiated correctly with the Bosch charger — no fault codes, no refused charge events, and current draw at motor start stayed within the overcurrent threshold the BMS monitors.
• Dock charging habit on cordless vacuums: Do not leave the BHN24L sitting on the charging dock between uses. Continuous trickle charging accelerates capacity fade in Li-ion packs faster than regular charge-discharge cycles. Charge to full, remove from the dock, and return it only when the pack is depleted.

Suction dropping before the battery indicator reaches low

The BHN24L motor draws more current when the filter is partially blocked — restricted airflow forces the motor to work harder to maintain suction. That elevated draw pulls the cell voltage down faster than the indicator circuit tracks, so suction degrades while the indicator still shows a charge remaining. A worn or degraded cell makes this worse because internal resistance climbs with age, amplifying the voltage sag under load. Check and clean the filter first; if sag continues with a clean filter on a new pack, the motor itself may be partially obstructed.

Motor cuts out mid-clean then recovers after a few seconds

This is a BMS overcurrent trip, not a flat battery. When sustained suction restriction forces the motor to draw beyond the pack's overcurrent threshold, the BMS cuts power to protect the cells. The pack recovers once internal temperature or current normalises — typically within a few seconds. A blocked filter is the most common trigger; a degraded original pack with high internal resistance reaches the trip threshold sooner. Clean the filter, then test: if the motor runs continuously without cutting out, the old pack was the cause. If it still trips, check the inlet and brush roll for blockage before fitting the replacement.