Philips Airfloss Pro Compatible Battery 3.7V 300mAh

Philips Airfloss Pro / HX8100 Series — 3.7V Li-Polymer Replacement Battery (AHB302540)

This is a 3.7V, 300mAh Li-Polymer battery for the Philips Airfloss Pro and Airfloss Ultra interdental cleaning devices. It fits the HX8100, HX8110, and over 36 additional models in the Airfloss range that share the AHB302540 cell. Replace it when the original cell no longer holds a usable charge or fails to charge at all.

• HX8100 and HX8110 platform fit: These models share the same 3.7V Li-Polymer cell format, connector pitch, and BMS handshake across the Airfloss Pro and Ultra lines. The AHB302540 part number spans this entire platform — one cell covers the full range.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Airfloss Pro dock. The BMS engaged correctly at low-voltage cutoff and accepted a full charge without triggering protection mode.
• Nozzle port and body seal check before reassembly: The Airfloss Pro forces pressurized water through a tight internal channel. If the body seal is compromised during a battery swap, moisture can reach the cell. Inspect and reseat the gasket before closing the housing — a leaking seal causes cell failure within weeks, not months.

Why the Airfloss Pro loses burst pressure before the battery indicator shows low

The Airfloss Pro's burst pump draws a short, sharp current spike each time it fires. As the Li-Polymer cell ages and internal resistance climbs, voltage sags under that spike even when resting voltage looks fine. The device's indicator reads resting voltage — not load voltage — so it can show two bars while the pump is already starved. The result is weak or inconsistent bursts long before the low-battery alert appears. Replacing the cell restores the voltage headroom the pump needs to fire at full pressure.

Airfloss Pro not charging in the dock after bathroom use

Cleaning product residue and water film on the dock's charging pins oxidise the contact surface over time. When resistance across the contacts rises past a threshold, the BMS sees an incomplete circuit and refuses to enter charge mode — the device appears completely dead, not just slow to charge. Wipe both the dock pins and the device's charging contacts with a dry cloth, then check for visible corrosion. If the contacts look clean and the issue persists, confirm charge voltage at the dock pins — you should read 5V DC before suspecting the cell itself.