Kenwood KNB-69L 7.4V 3400mAh Replacement Battery TK-2400VP

Kenwood TK-2400VP / TK-3400UP2 Series — 7.4V Li-ion Replacement Battery (KNB-69L)

This is a 7.4V, 3400mAh Li-ion replacement for the Kenwood KNB-69L battery pack. It fits the TK-2400VP, TK-3402U16P, TK-2402V16P, TK-3400UP2, and more than 20 additional TK-series handhelds. The pack slots into the standard Kenwood battery bay and connects through the same multi-pin contact strip as the OEM unit.

• TK-2400 and TK-3400 platform fit: These models share the same battery bay dimensions, contact pin layout, and BMS handshake protocol. One pack covers the entire platform because the voltage rail, physical housing, and connector footprint are identical across the series.
• Bench tested on actual hardware: We cycled this pack on a TK-2402V16P and a TK-3400UP2 dock. The BMS accepted the initial charge handshake without faulting, held voltage through repeated PTT transmit bursts, and the dock advanced to steady-green on both units.
• First-insertion contact check: If the charger 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 TK platform requires a clean contact cycle to accept the new BMS handshake before charging begins.

Why the TK-2400VP cuts out mid-transmission on a fresh KNB-69L

New Li-ion cells ship at storage voltage — typically around 3.7V per cell, or roughly 7.4V combined. When the radio keys up to transmit, RF output draws a sharp current spike. If the pack has not completed a full charge cycle first, the BMS reads that spike as an overcurrent event and trips the protection circuit, killing transmission. This is not a fault with the pack — it is the BMS doing its job on an undercharged cell. Charge the KNB-69L to full before first use in the radio, and the cutout will not recur.

Bar indicator showing one fewer bar than expected after inserting the KNB-69L

The TK-series radios use voltage-threshold bar indicators — each bar corresponds to a voltage bracket, not a percentage from a fuel gauge chip. A new pack at storage voltage sits at the lower end of the threshold scale, so the radio displays one bar short of full even though the cell is healthy. After a complete charge cycle, terminal voltage rises above the next threshold and the indicator corrects itself. If the bar count does not increase after a full charge, check that the dock contact pins are clean and making firm contact with the pack strip.