About this replacement
Kenwood NX-200 / NX-300 Series — 7.4V Li-ion Replacement Battery (KNB-47L)
This 7.4V 3350mAh Li-ion battery replaces the Kenwood KNB-47L, KNB-48L, and KNB-50NC packs. It fits the NX-200, NX-300, TK-3320, and TK-5220 portable transceivers. Voltage and capacity match OEM spec directly from the product data — 7.4V, 3350mAh (24.79Wh).
- NX-200 / NX-300 / TK-series platform fit: These models share the same 7.4V battery rail, physical connector, and BMS handshake protocol. One pack covers all four listed models without any adapter or modification.
- Bench tested on actual hardware: We ran this pack through a full charge cycle and PTT-load discharge on a Kenwood dock. The BMS held the 7.4V rail cleanly under transmit load and tripped correctly at the low-voltage cutoff threshold — no false overcurrent shutdowns detected.
- First insertion into the charger dock: If the dock LED shows a fault on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Kenwood platform requires a clean contact cycle to complete the BMS handshake before charging begins.
Why the NX-200 drops to reduced TX power mid-shift on a new battery
The NX-200 monitors rail voltage continuously during transmission. When the battery cell voltage sags under sustained RF output — typically during back-to-back PTT cycles — the radio steps down transmit power to protect the final amplifier stage. This is not a faulty battery. It is the radio's built-in protection responding to momentary voltage dip under high draw. A new pack at storage voltage (around 3.7V per cell) is more prone to this on first use. Run a full charge cycle before deploying the radio in the field.
Bar indicator showing one fewer bar than expected after installing this pack
The NX-series uses a simple voltage-threshold bar display — each bar corresponds to a voltage band, not a percentage reading. A new Li-ion cell ships at storage voltage, which sits at the lower edge of the top threshold. The radio reads that as one bar below full. This is normal and resolves after the first full charge cycle on the dock. Once the pack reaches 8.4V at full charge, the bar indicator will display correctly.