About this replacement
Logitech 981-001151 Series — 3.7V Li-Polymer Replacement Battery (533-000214)
This is a 3.7V, 350mAh Li-Polymer battery built to fit the Logitech 981-001151 wireless headset and related models including 981-001298, 981-001303, and 981-001310. It matches the OEM part number 533-000214 and uses the same slim 41.70 x 39.40 x 4.70mm cell profile as the factory pack. When the original cell degrades, this swap restores full wireless audio and headset controls.
- Multi-model fit across the 981-00 series: These headsets share the same base station charging contacts, BMS handshake protocol, and 3.7V cell footprint. One battery services the full range without modification.
- Bench tested on actual hardware: We cycled this cell through the base station charging circuit and confirmed the BMS completed its full handshake sequence. The protection circuit triggered correctly at low-voltage threshold and recharged without error flags.
- First charge in the base station: Seat the headset in the base and run a full uninterrupted charge cycle before use. DECT headsets need the base to log the new cell before the talk-time indicator reads accurately — skipping this step causes the display to misreport charge state for several sessions.
Voltage sag under combined audio and DECT radio draw
The 981-001151 drives both audio processing and the DECT radio transmitter from the same 3.7V cell. At peak transmission the combined draw briefly spikes above steady-state current. A worn or storage-voltage cell cannot hold the rail steady during that spike, which causes the headset to cut out or reset mid-call. A fresh cell at full charge maintains the voltage rail through those peaks without dropout.
Base station shows full charge but headset cuts off after short use
A new cell ships at storage voltage — typically around 3.6V — not at full 4.2V. The base station reads the cell as charged before it has completed a true full cycle, so the charge indicator turns green early. The headset then runs on a partially charged pack and cuts off sooner than expected. Seat the headset in the base for a complete uninterrupted charge cycle; after that first full cycle the base-to-headset charge state reporting aligns correctly.