About this replacement
AKG C50BT / Y50BT — 3.7V Li-Polymer Replacement Battery (P083040-Q02)
This is a 3.7V, 1000mAh Li-Polymer replacement battery for the AKG C50BT and Y50BT wireless Bluetooth headsets. It replaces OEM part number P083040-Q02 and fits directly into the original battery bay. Use this when the existing cell no longer holds a charge or talk time has dropped noticeably.
- C50BT and Y50BT shared platform: Both models run on the same 3.7V cell with an identical footprint (42 × 30 × 7.80mm) and share the same BMS handshake protocol — one part number covers both headsets without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the C50BT platform. The BMS accepted the new pack without error, and protection circuits responded correctly to both end-of-charge and low-voltage cutoff thresholds.
- First-cycle base station charge: Seat the headset in the AKG charge cradle and run a complete charge cycle before using it for calls. The base station logs the new cell's state during this cycle — skipping it can cause the talk-time indicator to read inaccurately for days.
Why the C50BT cuts out mid-call on a new battery
The C50BT draws from two loads simultaneously — the audio codec and the Bluetooth radio. On a freshly installed cell that hasn't completed its first full cycle, the BMS may interpret a combined-load voltage dip as a fault and trip the protection circuit. This looks identical to a dead battery but is a BMS state issue, not a capacity problem. Seat the headset in the base, let it charge fully to 4.2V, then retry — most cutout events resolve after that first complete cycle.
Base station showing a charging error after fitting the new pack
If the AKG base flashes an error or refuses to begin charging after a battery swap, the BMS handshake between the new cell and the cradle's charge controller hasn't completed. This typically happens when the replacement cell ships at storage voltage — around 3.6–3.7V — which some cradles flag before initiating a charge cycle. Remove the headset, wait ten seconds, reseat it firmly, and re-dock. If the error persists, hold the headset in the cradle contacts manually for thirty seconds to allow the handshake to initiate at low current.