KNB-84L Kenwood NX-240V Replacement Battery 7.4V 2000mAh

Kenwood NX-240V / NX-340U / NX1200 Series — 7.4V Li-ion Replacement Battery (KNB-84L)

This is a 7.4V, 2000mAh (14.8Wh) Li-ion replacement battery for the Kenwood NX-240V, NX-340U, NX1200, NX-1200A, and compatible NX-series portables. It uses the KNB-84L footprint with the same connector, latch geometry, and BMS communication protocol as the OEM pack. Voltage and capacity figures match the original Kenwood specification.

• NX-series platform fit: The NX-240V, NX-340U, NX1200, and NX-1200A share the same 7.4V battery bay, physical latch, and BMS handshake protocol — which is why one pack covers all of them. The dock and radio firmware read pack voltage and BMS data through the same contact array across the whole family.
• Bench tested on actual hardware: We cycled this pack through full charge and simulated PTT transmit loads on the NX platform. The BMS handled the transmit current spike cleanly without tripping overcurrent protection, and the charger dock accepted the pack and progressed to ready status normally.
• First insertion on the KSC-35SK or KSC-43K dock: If the dock fault LED stays on after inserting a fresh pack, remove the battery and wipe the gold contact strip with a dry cloth before reseating. The Kenwood dock requires a clean contact cycle to complete the BMS handshake — a residue film from factory storage is often enough to block it on the first attempt.

Why the NX-240V cuts out mid-transmission on a brand-new battery

New Li-ion cells ship at storage voltage — typically 3.6–3.7V per cell, giving roughly 7.2–7.4V at the pack terminals. When you key the PTT, transmit current can spike sharply for the first few seconds. If the pack hasn't completed a full charge cycle, the BMS may read that voltage dip as an undercurrent fault and cut output momentarily. The fix is straightforward: charge the pack fully on the KSC-35SK or KSC-43K before the first field use. A complete charge cycle brings each cell to 4.2V and allows the BMS to set its internal reference thresholds correctly.

Bar indicator showing one fewer bar than expected after swapping to the new KNB-84L

The NX-series bar indicator reads pack voltage against fixed thresholds — it does not track charge history or cell chemistry. A new cell at storage voltage (around 7.2V) sits at or just below the threshold for the top bar, so the radio legitimately displays one fewer bar even with a fresh pack. This is not a fault with the battery. Charge the pack fully to 8.4V on the dock, then reinsert — the indicator will step up to full bars once the pack voltage clears the top threshold.