Bosch BHN20110/01 Replacement Battery 20.4V 2000mAh

Bosch BHN20110 Series — 20.4V Ni-MH Replacement Battery (11051746)

This is a 20.4V Ni-MH replacement battery pack for the Bosch BHN20110 cordless handheld vacuum. It fits the /01, /02, /03, and /04 variants of that model. Capacity is 2000mAh (40.8Wh), matching the original specification.

• BHN20110 variant compatibility: All four BHN20110 suffix variants share the same battery bay geometry, connector pinout, and BMS handshake protocol. One pack covers the full production run of this vacuum series without modification.
• Bench tested on actual hardware: We cycled this pack through full charge and discharge on the BHN20110 platform. The BMS responded correctly to the charger handshake, accepted full charge without fault codes, and released current to the motor at rated voltage under load.
• Dock charging habit on this vacuum: Do not leave the BHN20110 sitting on the charging dock permanently. Ni-MH cells in continuous trickle charge degrade faster than cells charged only when depleted. Charge to full, then remove the vacuum from the dock.

Suction dropping before the battery indicator reaches low

On the BHN20110, suction loss often happens at the motor level before the battery gauge registers a problem. A partially blocked filter forces the motor to draw above its rated current. The BMS detects the excess draw and reduces output voltage to protect the cells. Clear or replace the filter first — if suction restores at full power, the battery was not the cause.

Motor cutting out mid-use and then recovering after a short pause

This is a BMS overcurrent trip, not a dead battery. When the motor sustains restricted airflow — blocked nozzle, saturated filter, or heavy carpet fibres — current draw spikes past the BMS threshold and the pack shuts off as protection. The BMS resets after the cell temperature drops, which is why the vacuum restarts after a minute or two. Clear the blockage and check the filter condition before attributing the fault to the battery.