Kenwood KNB-63L 7.4V Replacement Battery TK-2000K Radio

Kenwood TK-2000K / TK-3000K Series — 7.4V Li-ion Replacement Battery (KNB-63L)

This is a 7.4V, 1300mAh Li-ion replacement battery for the Kenwood TK-2000K, TK-3000K, TK-3000K2, TH-K20, and compatible models. It replaces OEM part numbers KNB-63L and KNB-65L. Same voltage, same form factor, same connector orientation as the original pack.

• TK/TH-series compatibility: The TK-2000K, TK-3000K, TK-3000K2, and TH-K20 share the same battery bay geometry, 7.4V voltage rail, and BMS handshake protocol — which is why a single pack covers all of them. The KNB-63L and KNB-65L are electrically identical for this platform.
• Bench tested on actual hardware: We ran this pack on a TK-3000K dock and monitored the BMS through charge accept, full charge, and a transmit-load cycle. The protection circuit held within spec across all three stages, with no overcurrent trip during PTT simulation.
• First insertion on a Kenwood dock: If the charger LED blinks fault on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Kenwood dock requires a clean contact cycle to complete the BMS handshake before it will begin charging.

Why the TK-2000K cuts out mid-transmission on a new battery

New cells ship at storage voltage — typically 3.6–3.7V per cell, which puts the pack around 7.2V total. When you key up on a fresh-from-box battery, the transmit current spike can pull the cell voltage below the BMS low-voltage cutoff threshold before the cells have been through a full charge cycle. The radio cuts out not because the battery is faulty, but because the BMS is doing its job protecting cells that haven't yet been brought to full working voltage. Charge the pack completely before first use to bring both cells above 4.1V and eliminate this trip condition.

Bar indicator shows one fewer bar than expected after fitting new pack

The TK-series uses voltage-threshold bar indicators, not a fuel gauge chip. When a new pack arrives at storage voltage near 7.2V, the radio reads that as a partially depleted state and displays two bars instead of three. This is not a capacity fault — it is the radio correctly reporting current cell voltage. Put the pack through one full charge cycle in the dock until the LED goes green, and the indicator will show full bars at 8.2–8.4V.