Nolan N-COM B902 L Replacement Battery 3.7V 800mAh

Nolan N-COM B902 L / B902 R (2023) — 3.7V Li-Polymer Replacement Battery (BATTERIA 07)

This 3.7V 800mAh Li-Polymer cell replaces the original battery in the Nolan N-COM B902 L and B902 R (2023) helmet communication systems. It restores full function to the Bluetooth audio unit — music streaming, GPS audio, and rider-to-rider communication. Capacity matches the OEM specification at 800mAh (2.96Wh).

• B902 L and B902 R platform fit: Both models share the same 3.7V cell, connector pinout, and BMS handshake protocol. The physical cell dimensions — 43.80 × 34.20 × 6.00mm — match the housing recess in both units, so no fitment modification is needed.
• Bench tested on actual hardware: We cycled this cell through the N-COM BMS under combined Bluetooth audio and radio draw. The BMS accepted the new pack without flagging a cell mismatch, and charge termination occurred cleanly at full capacity.
• First-charge protocol for N-COM units: Seat the unit in its cradle and run a complete charge cycle before pairing or making any calls. The N-COM system logs the new cell during this cycle — skipping it causes the talk-time indicator to read incorrectly for the first several sessions.

Why the B902 cuts out mid-call even with a new battery installed

The N-COM B902 draws on two loads simultaneously during a call — the Bluetooth audio circuit and the RF communication layer. That combined draw creates brief voltage dips the BMS interprets as undervoltage, triggering a protective cutoff. A new cell at storage voltage (typically 3.6–3.7V) is more vulnerable to these dips than a fully conditioned pack. Running two to three complete charge-discharge cycles brings the cell to its rated capacity and reduces the depth of those sag events.

Talk time shorter than rated across the first few uses

Li-Polymer cells ship at partial charge and do not deliver full capacity on the first cycle. The N-COM B902's internal gauge calibrates against actual charge throughput, so early sessions will show reduced talk time even if the indicator reads full. Capacity improves incrementally over three to five full cycles as the electrolyte settles and the gauge recalibrates. After cycle five, measure resting voltage after a full charge — it should sit at 4.18–4.20V, confirming the cell has reached rated capacity.