About this replacement
Jabra Elite 85H / Evolve2 85 — 3.7V Li-Polymer Replacement Battery (AK-E285)
This is the AK-E285 Li-Polymer cell for the Jabra Elite 85H and Evolve2 85 wireless headphones. It runs at 3.7V with a 750mAh (2.78Wh) capacity. Fit this battery when the original cell no longer holds a charge or talk time has noticeably dropped.
- Elite 85H and Evolve2 85 compatibility: Both models share the same 3.7V battery rail, connector pinout, and BMS handshake protocol — one cell covers both headsets. The AK-E285 part number is common to the entire platform.
- Bench tested on actual hardware: We cycled this cell through charge, idle, and active ANC-plus-Bluetooth draw states. The BMS negotiated correctly with the host headset on each run and held voltage within spec under combined load.
- First-cycle base station protocol: Seat the headset in the base station and complete one full charge cycle before taking a call. The base station needs that full cycle to log the new cell — until it does, the talk-time indicator will read inaccurately.
Why the Elite 85H cuts out mid-call on a new battery
The Elite 85H draws simultaneously from the audio processor, ANC circuit, and Bluetooth radio during a call. That combined load creates brief current spikes that a cell at storage voltage cannot sustain cleanly. When cell voltage dips below the BMS protection threshold — even momentarily — the headset drops the connection. Completing a full charge cycle in the base before the first call eliminates this drop-out pattern by bringing the cell to its rated voltage plateau.
Base station shows full charge but headset shuts off after short use
A new Li-Polymer cell ships at storage voltage, typically around 3.6–3.7V, not at peak charge. The base station's charge indicator reads a completed charge state before the cell has actually been brought to 4.2V through a proper CC/CV cycle. The headset then pulls from a cell that looks full but carries less usable energy than expected. Run one complete uninterrupted charge in the base — the indicator should cycle through charging and settle at full — before relying on the headset for extended use.