Kenwood KNB-16A Replacement Battery 7.2V 1800mAh Ni-MH

Kenwood TK-180 / TK-280 Series — 7.2V Ni-MH Replacement Battery (KNB-16A)

This is a 7.2V 1800mAh Ni-MH battery pack for Kenwood portable two-way radios. It fits the TK-180, TK-190, TK-280, TK-290, and more than a dozen additional TK-series models sharing the same battery bay and connector. Voltage and form factor match the KNB-16A, KNB-17A, KNB-17N, KNB-21N, and KNB-52N OEM packs.

• TK-180 / TK-280 platform fit: These models share the same 7.2V two-cell Ni-MH battery bay, identical contact pin layout, and BMS handshake protocol. A single pack design covers both the VHF and UHF variants because the power rail and connector are the same across the platform.
• Bench tested on actual hardware: We ran this pack through charge and transmit cycles on a TK-280. The BMS accepted the charge current without tripping on PTT keyup, and held voltage above the radio's low-battery threshold through sustained TX loads.
• First insertion into the charger dock: If the dock shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Kenwood charger platform requires a clean contact cycle to accept the new BMS handshake before the charge cycle begins.

Why the TK-180 cuts out mid-transmission on a freshly inserted pack

A new Ni-MH pack ships at storage voltage, typically around 6.0–6.5V across the six cells. When PTT is pressed, transmit current spikes sharply and the BMS may trip the pack offline if cell voltage has not recovered to the radio's minimum operating threshold. This is not a faulty battery — it is the BMS responding correctly to undervoltage under load. Put the pack on charge for a full cycle before first use in the field. After a full charge, the resting voltage should read 7.2–7.6V and the radio will hold TX without cutting out.

Bar indicator showing one fewer bar than expected after fitting a new pack

Kenwood TK-series radios use voltage-threshold bar indicators — each bar corresponds to a specific voltage band, not a calculated capacity percentage. A new pack at storage voltage sits in the lower threshold band, so the display shows one or two bars even though the pack is not depleted. This clears after a full charge cycle drives cell voltage to its rated peak. If the bar count stays low after a confirmed full charge, check that the charger dock contacts are clean and making firm contact with the battery's gold strip.