HYT TC-610 BL1204 Replacement Battery 7.4V 1200mAh

HYT TC-610 Series — 7.4V Li-ion Replacement Battery (BL1204 / BL2001)

This is a 7.4V, 1200mAh lithium-ion battery for the HYT TC-610, TC-610P, TC-610S, and TC-618 portable two-way radios. It replaces OEM part numbers BL1204 and BL2001. Voltage and connector match the original pack, so the radio's charging dock and BMS handshake accept it without modification.

• TC-610 platform compatibility: The TC-610, TC-610P, TC-610S, and TC-618 all share the same battery bay dimensions, contact pin layout, and 7.4V voltage rail. One battery fits all four because HYT standardised the BMS communication protocol across this radio family.
• Bench tested on actual hardware: We cycled this pack on a TC-610 body and monitored BMS response through full transmit loads. The protection circuit handled repeated PTT-triggered current spikes without tripping into lockout, and the dock accepted the handshake on first insertion.
• First-insertion contact check: If the HYT charging dock shows a fault LED on the first seating, remove the battery and wipe the gold contact strip with a dry cloth before reseating. The TC-610 dock requires a clean contact cycle to complete the BMS handshake — a single wipe resolves this in most cases.

TC-610 cuts out mid-transmission on a new BL1204 pack

A new lithium-ion cell ships at storage voltage — typically 3.6–3.7V per cell, not full charge. When the TC-610 fires a transmit burst, it draws a sharp current spike that can push a low-voltage cell into BMS overcurrent territory. The protection circuit trips the pack off before the transmission completes. Running one full charge cycle before first use brings both cells to 4.2V and raises the pack's headroom above the BMS overcurrent threshold.

Bar indicator shows one fewer bar than expected after installing a new pack

The TC-610 reads battery level through voltage thresholds — each bar on the display corresponds to a voltage band. A new pack at storage voltage sits inside the lower threshold band, so the indicator reports one or two bars even though the cell is not depleted. This is not a fault with the battery or the radio. Charge the pack to full and the indicator will step up to the correct bar count, which for a fresh 7.4V cell at capacity reads at the top threshold.