Turtle FT603048P Wireless Headset Compatible Battery 3.7V 900mAh

Turtle FT603048P — 3.7V Li-Polymer Replacement Battery

This 3.7V, 900mAh Li-Polymer cell replaces the OEM pack (FT603048P) in Turtle wireless headsets. It restores audio transmission and Bluetooth connectivity after the original cell has degraded or stopped holding a charge. Dimensions are 48.70 × 30.80 × 5.90mm — confirm these against your existing cell before fitting.

• Turtle wireless headset fit: The FT603048P part number is shared across Turtle's slim wireless headset line because the voltage rail, cell footprint, and connector pinout are common across that platform. The BMS in the headset reads cell voltage on connect — matching the 3.7V nominal is what matters for recognition.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench with a Turtle headset unit. The BMS accepted the pack without a fault state, and charge current tapered correctly at full capacity.
• First-cycle base station charge: Seat the headset in the base station and let it complete a full charge cycle before taking a call. DECT and Bluetooth headsets log the new cell during that first supervised cycle — the talk-time estimate on the base display will not be accurate until that cycle completes.

Base station showing charging error after fitting a new pack

The base station monitors the BMS handshake when the headset is docked. If the new cell ships at storage voltage — typically around 3.6V — the base can flag a fault instead of starting a normal charge cycle. Remove the headset, wait ten seconds, and re-dock it. This forces the base to re-poll the BMS. If the error persists, the cell voltage may have dropped below the BMS recovery threshold, and a five-minute bench charge at low current is needed to bring it back above 3.0V before normal charging resumes.

Headset cuts out mid-call even with a recently charged battery

This is a voltage sag issue, not a capacity problem. During a call, the headset draws current for both the audio codec and the radio transmitter simultaneously — that combined draw causes a momentary voltage dip. On a cell that is even partially degraded, the dip is large enough to trip the BMS undervoltage cutoff, which kills the headset mid-transmission. Fit the new pack, complete two full charge-discharge cycles through the base station, and the cell's internal resistance will settle. If cut-outs continue after three cycles, check that the headset's dock contacts are clean — resistance at the connector compounds the sag.