About this replacement
Kenwood TK-2400VP / TK-3400UP2 Series — 7.4V Li-ion Replacement Battery (KNB-69L)
This is a 7.4V, 2600mAh lithium-ion replacement for the Kenwood KNB-69L battery pack. It fits the TK-2400VP, TK-3402U16P, TK-2402V16P, TK-3400UP2, and over 21 additional TK-series portables that share the same form factor and connector. Voltage and capacity match the OEM spec directly from the product data.
- TK-2400 and TK-3400 platform fit: These models share a common battery bay dimension, contact pin layout, and BMS handshake protocol. The pack slots into any of these radios without adapter plates or wiring changes — the voltage rail and connector are identical across the group.
- Bench tested on actual hardware: We cycled this pack through full charge and load discharge on a TK-series dock. The BMS responded correctly to transmit-load spikes, holding voltage within the expected window without tripping overcurrent cutoff.
- First insertion on a Kenwood dock: If the charger shows a fault LED on first seating, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The TK-series dock requires a clean contact cycle to complete the BMS handshake before it will begin charging.
Why the TK-2400VP cuts out mid-transmission on a fresh battery
During PTT, the radio draws a sharp current spike to power the RF output stage — this is the highest load the battery sees in normal use. If the BMS detects that spike as an overcurrent event, it trips the protection circuit and cuts power instantly, dropping the transmission. This happens most often when a new pack is at storage voltage rather than a full charge, because internal cell impedance is higher at lower states of charge. A full charge cycle before field use brings cell impedance down and allows the BMS to pass the transmit surge without tripping. Target voltage after a full charge is 8.4V at the pack contacts.
Bar indicator showing one fewer bar than expected after swap
New lithium-ion cells ship at roughly 3.7V per cell — around 7.4V total — which is the mid-point storage voltage, not a full charge. The TK-series radio reads pack voltage against fixed thresholds to drive the bar display, so a pack at storage voltage will register one or two bars even though nothing is wrong with the cells. This is not a capacity fault. Seat the pack in the dock and run a complete charge cycle. Once the pack reaches 8.4V, the bar indicator will reflect the correct state.