About this replacement
Kenwood NX-200S / NX-300S Series — 7.4V Li-ion Replacement Battery (KNB-33L)
This 7.4V, 1800mAh Li-ion battery replaces the KNB-33L, KNB-41NC, and KNB-54N packs across Kenwood's NX-series portable radio lineup. It fits the NX-200S, NX-210, NX-300S, and NX-410, among others. Voltage and connector match the original spec — no adapters, no modification.
- NX-200S / NX-300S platform fit: These models share a common battery bay geometry and 7.4V nominal voltage rail. The KNB-33L form factor and contact layout carry across the NX-200 and NX-300 sub-variants, which is why one SKU covers both series without hardware changes.
- Bench tested on actual hardware: We ran this pack through a full charge cycle and PTT stress test on the NX-200S. The BMS held steady through repeated transmit bursts without tripping overcurrent protection, and the charger dock accepted the pack after a single clean contact cycle.
- Dock insertion on first use: If the charger shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Kenwood NX-series dock requires a clean contact cycle to complete the BMS handshake before it begins charging.
Why the NX-200S cuts out mid-transmission on a fresh pack
A new Li-ion cell ships at storage voltage — typically around 3.7–3.8V per cell, not the 4.2V peak of a full charge. When you key up on a radio at storage voltage, the transmit current spike can push the BMS into temporary overcurrent cutoff. The radio drops the transmission, then recovers within seconds. This is not a fault — it is the BMS protecting an undercharged cell. Charge the pack fully before your first transmission and the cutout stops.
Bar indicator reads one fewer bar than expected after swap
The NX-series uses a simple voltage-threshold bar indicator — each bar maps to a voltage band, not a calibrated capacity reading. A new pack at storage voltage sits at the lower end of the threshold curve, so the radio displays fewer bars than the pack actually holds. This is not a defective cell. Put the pack on charge until the dock goes green, then insert it — the indicator will read correctly at 8.4V full charge.