Kenwood NX-200 Replacement Battery KNB-47L 7.4V 2800mAh

Kenwood NX-200 / NX-300 Series — 7.4V Li-ion Replacement Battery (KNB-47L)

This is a 7.4V 2800mAh Li-ion replacement battery for the Kenwood NX-200, NX-300, TK-3320, and TK-5220 series two-way radios. It replaces OEM part numbers KNB-47L, KNB-48L, and KNB-50NC. The pack matches the original connector, BMS handshake protocol, and form factor for these Kenwood platforms.

• NX-200 / NX-300 / TK-3320 / TK-5220 platform fit: These models share the same 7.4V battery bay, contact rail geometry, and BMS communication protocol. One pack covers the full group — no adapter or modified contacts required.
• Bench tested on actual hardware: We ran this pack on an NX-200 and cycled through full PTT transmit loads. The BMS held voltage through sustained RF output without triggering overcurrent cutoff, and the charger dock accepted the pack and progressed to full charge without fault.
• First insertion into the charger dock: If the dock shows a fault LED on first seating, 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 cuts out mid-transmission on a new KNB-47L

When a PTT transmission begins, the radio draws a sharp current spike to power the RF output stage — often 2A or more for a fraction of a second. If the BMS reads that spike as an overcurrent fault, it trips and drops the circuit before the transmission completes. This is more likely on the first few cycles when cell impedance is slightly elevated from storage. Run three to five full charge and transmit cycles and the BMS recalibrates its overcurrent threshold to the actual cell behaviour. After conditioning, mid-transmission cutouts on this pack stop.

Bar indicator showing one fewer bar than expected after a full charge

New Li-ion cells ship at storage voltage — typically around 3.7V per cell, which puts the pack near 7.4V total. The NX-200's bar indicator uses fixed voltage thresholds, so a pack at storage voltage reads as partially depleted even if the charger has just finished. Charge the pack fully, seat it in the radio, and let the radio sit powered on for two minutes before checking the indicator. After the BMS settles and the radio takes a fresh voltage reading, the bar count will reflect the actual state of charge at or above 8.2V.