Cardo Q1 Wireless Headset Replacement Battery BAT00003 3.7V

Cardo Q1 / Scala Rider Q3 Series — 3.7V Li-Polymer Replacement Battery (BAT00003)

This is a 3.7V, 450mAh lithium-polymer cell that replaces part number BAT00003 in the Cardo Q1, Q3, Scala Rider Q3, and Scala Rider FM Bluetooth motorcycle intercom headsets. It fits the slim 48.70 × 20.00 × 4.50mm cavity in each unit and connects via the original BMS circuit. When the stock cell no longer holds a charge, this swap restores full intercom and phone functionality.

• Q1, Q3, and Scala Rider compatibility: These models share the same 3.7V nominal rail, BAT00003 connector footprint, and BMS handshake protocol — which is why one cell covers all four variants. The battery management circuit in each headset reads cell state through the same pin configuration, so no firmware or hardware change is needed.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles against the Cardo BMS. The protection circuit tripped correctly at low-voltage cutoff, and the cell accepted a full charge without thermal event or error flag on the base station display.
• First-charge protocol for Cardo intercoms: Seat the headset in its base station and run one complete charge cycle before your first call. Cardo base stations log the new cell during this cycle — skipping it causes the talk-time indicator to read inaccurate until the BMS has a full baseline.

Base station showing full charge but headset cuts off after short use

A replacement cell arrives at storage voltage — typically 3.6–3.7V — not fully charged. The base station LED can flip to "full" prematurely if the BMS reads this resting voltage as near-capacity before a proper charge cycle has run. The headset then cuts off quickly because the actual usable charge is well below rated capacity. Fix this by placing the unit in the base for an uninterrupted charge until the indicator completes naturally, starting from a fully discharged state if possible.

Headset cutting out mid-call on the first few uses after replacement

The Cardo Q1 draws current simultaneously from the audio amplifier and the Bluetooth radio during an active call — this combined load causes a voltage sag that a cell in its first one to three cycles handles less efficiently than a conditioned one. The BMS interprets the sag as a low-cell event and cuts power to protect the cell. Capacity and sag resistance improve over three to five full charge-discharge cycles, so complete those cycles before judging talk-time performance.