About this replacement
Nolan N-COM 901 X Series — 3.7V Li-ion Replacement Battery (ZCF603443)
This is a 3.7V 900mAh Li-ion cell for the Nolan N-COM 901 X motorcycle helmet communication system. It fits the unit that mounts inside the helmet shell and handles Bluetooth audio, rider-to-rider comms, and phone calls. Replaces OEM parts ZCF603443, SPCOM00000038, and NC003-BA-38.
- N-COM 901 X, 901S, BX1 platform fit: These models share the same cell format, connector orientation, and BMS handshake protocol. The 47.00 × 35.40 × 7.60mm footprint fits the cavity without modification, and the protection circuit matches the charge termination logic the base station expects.
- Bench tested on actual hardware: We cycled this cell through the N-COM base station and confirmed charge acceptance, full cutoff at 4.2V, and clean BMS communication. The protection circuit tripped correctly at low-voltage threshold and recovered on reconnect.
- First-charge protocol for N-COM units: Seat the headset in the base station and let it complete a full charge cycle before making a call. The base station logs the new cell during that first cycle — until it does, the talk-time indicator reads incorrectly.
Talk time shorter than rated on the first few rides
Fresh Li-ion cells don't hit full capacity on cycle one. The electrodes need three to five full charge-discharge cycles before the cell reaches its rated 900mAh. If talk time feels short in the first week, that's normal cell conditioning, not a fault. Run three complete cycles through the base station and talk time will improve each time.
Base station shows full charge but headset cuts off after short use
A new cell ships at storage voltage — typically around 3.6–3.7V — not at full charge. If the base station reads that as "charged" and the headset cuts off quickly, the cell hasn't completed its first full cycle yet. Remove the headset, reseat it firmly in the base station, and let the charge cycle run to completion. The BMS handshake completes at the end of that cycle, and the base station will then report charge state accurately.