About this replacement
Plantronics Pulsar 590 Series — 3.7V Li-Polymer Replacement Battery (69746-01)
This is a 3.7V, 240mAh Li-Polymer replacement battery for the Plantronics Pulsar 590, 590A, and 590E wireless headsets. It slots directly into the headset housing and restores wireless call function when the original cell no longer holds a charge. OEM part numbers 69746-01, 423629T, and 67777-01 all cross to this pack.
- Pulsar 590 / 590A / 590E fitment: All three variants share the same 3.7V cell footprint, connector pinout, and BMS handshake profile — that's why one pack covers the full Pulsar 590 family without modification.
- Bench tested on actual hardware: We cycled this pack through charge and discharge on the Pulsar 590 base station. The BMS completed its handshake correctly and the base station's charge indicator cleared without error.
- First charge in the base station: Seat the headset in the base and let it run a complete charge cycle before taking a call. The base station logs the new cell during that first cycle — without it, the talk-time estimate on the base display will read inaccurate until the handshake finishes.
Why the Pulsar 590 cuts out mid-call on a new battery
The Pulsar 590 draws current from two loads at once — the audio codec and the DECT radio transmitter. On a new cell stored at partial voltage, that combined draw can push current demand past what the BMS allows, triggering a protection cutoff. This isn't a faulty pack; it's the BMS doing its job before the cell has been properly conditioned. One full charge cycle in the base station raises the resting voltage to the correct operating level and the cutouts stop.
Base station showing a charging error after fitting a new pack
The Pulsar 590 base station checks for a valid BMS response before it begins charging — if it doesn't get one, it flags a charge error rather than push current into an unknown cell. This usually means the new pack was seated before completing a rest period after shipping. Remove the headset, wait two minutes, then reseat it firmly and dock it in the base. If the error clears within 30 seconds of docking, the handshake has completed and charging will proceed normally from a starting voltage near 3.6V.