AKG C50BT Replacement Battery 3.7V 1000mAh Li-Polymer P083040-Q02

AKG C50BT / Y50BT — 3.7V Li-Polymer Replacement Battery (P083040-Q02)

This 3.7V 1000mAh (3.7Wh) lithium-polymer cell replaces part number P083040-Q02 in the AKG C50BT and Y50BT Bluetooth headsets. Both models run the same internal cell at the same voltage rail with the same connector footprint. Dimensions are 41.50 × 30.00 × 7.80mm — measure your original before ordering if you are unsure.

• C50BT and Y50BT shared platform: Both headsets use the same PCB layout, BMS handshake protocol, and connector pinout — which is why they share one cell. Swapping the battery does not require re-pairing the headset to your device; the Bluetooth profile sits in firmware, not the battery.
• Bench tested on actual hardware: We ran P083040-Q02 replacements through charge-discharge cycles on the C50BT platform. The onboard BMS accepted the new cell without a protection-trip event, and charge termination fired correctly at full capacity.
• First-cycle charging on the C50BT: Bring the headset to full charge via USB before the first call. The C50BT's talk-time counter reads the cell state logged during that initial charge cycle — skipping it causes the headset to underestimate remaining capacity for the first several uses.

Why the C50BT cuts out mid-call on a new battery

The C50BT draws simultaneously from the audio amplifier and Bluetooth radio during a call. That combined load can spike current demand sharply — more than idle playback alone. If the replacement cell's BMS has not yet logged a full cycle, it may interpret the spike as an overcurrent event and trip protection. Running two or three full charge-discharge cycles before extended calls lets the BMS calibrate its threshold correctly and stops false cutoffs.

Talk time shorter than rated on the first few charges

A new lithium-polymer cell does not deliver full rated capacity on day one. Electrolyte wetting across the electrode surface improves over the first three to five full cycles, and actual capacity rises with each one. If the headset seems to lose charge faster than expected in the first week of use, that is normal cell conditioning — not a fault. By the fifth full cycle, capacity should be at or very close to the rated 1000mAh.