Logitech H820e Replacement Battery 3.7V 450mAh

Logitech H820e — 3.7V Li-Polymer Replacement Battery (533-000095)

This 3.7V, 450mAh Li-Polymer cell replaces the original battery in the Logitech H820e wireless headset. It fits both the mono and duo variants of the H820e, which use the same battery form factor and connector. Capacity is drawn from the product specification — 450mAh (1.67Wh).

• H820e platform fit: The H820e runs its DECT radio and audio processing from a single 3.7V Li-Polymer cell. The BMS on this replacement matches the voltage profile and charge termination logic the Logitech base station expects — no modifications needed.
• Bench tested on actual hardware: We cycled this cell through the H820e base station and confirmed the BMS completed a full handshake without triggering a charge error. The base station's LED sequence ran normally through charge and standby states.
• First-cycle dock protocol: Seat the headset in the base station and leave it for a full uninterrupted charge before taking a call. The H820e base station needs to complete one full charge cycle to log the new cell — until it does, the talk-time indicator will under-report remaining capacity.

Base station not recognising the new pack after swap

The H820e base station communicates with the battery BMS before it begins charging. If the cell arrives at storage voltage — typically around 3.6V — the base may display a charge error or loop without initiating a charge cycle. This is a BMS initialisation issue, not a fault with the cell itself. Seat the headset firmly, wait 60 seconds, then remove and reseat it. If the error persists, the cell voltage may need a brief pre-charge — most H820e base stations will recover this automatically within two or three seating attempts.

Headset cuts out mid-call on a new battery

The H820e draws simultaneously from the DECT radio and audio amplifier during active calls. On a freshly installed cell, this combined draw can trigger a BMS undervoltage cutoff if the cell hasn't completed its first conditioning cycle. The symptom is an abrupt audio drop rather than a gradual fade. Run two to three full charge-to-discharge cycles through normal headset use and the cutoff threshold will stabilise — cell voltage under load should hold above 3.4V once conditioned.