HYT BL1703 TC-700 Two-Way Radio Replacement Battery 7.2V 2000mAh

HYT TC-700 / TC-780 Series — 7.2V Ni-MH Replacement Battery (BL1703)

This is a 7.2V, 2000mAh nickel-metal hydride battery for the HYT TC-700, TC-700U, TC-780, and TC-780M two-way radios. It replaces OEM part numbers BL1703, BL2102, BH1801, BL1703Li, and BL-2102Li. The pack slots into the same battery bay and uses the same connector as the original HYT unit.

• TC-700 and TC-780 platform fit: Both the TC-700 and TC-780 lines share the same 7.2V battery rail, bay geometry, and contact layout. That common spec is why a single pack covers both model families without any adapter or modification.
• Bench tested on actual hardware: We cycled this pack through the HYT standard charge dock and monitored BMS behaviour across transmit-current spikes. The protection circuit held stable during repeated PTT events and the pack accepted a full charge cycle without dock fault codes.
• Contact strip condition before first dock insertion: Ni-MH packs can leave microscopic residue on the gold contact strip during shipping. Wipe the contacts with a dry cloth before seating the pack in the dock. A single contaminated contact can prevent the dock from initiating the charge handshake and trigger a fault LED on the HYT charger.

Why the TC-700 cuts out mid-transmission on a freshly inserted battery

The TC-700 draws a sharp current spike the moment PTT is pressed — transmit current can exceed standby draw by a factor of five or more. If the Ni-MH pack is still at storage voltage rather than a full charge, that spike can push the pack voltage below the BMS cutoff threshold in under a second. The radio interprets this as a depleted pack and drops the transmission. This is not a faulty battery — it is a cell that shipped at storage charge and has not yet been fully conditioned by a complete charge cycle.

Bar indicator showing one fewer bar than expected after a full charge

The TC-700 and TC-780 use a simple voltage-threshold bar indicator — each bar corresponds to a voltage band, not a calibrated fuel gauge. A new Ni-MH cell fresh off its first charge often sits slightly below its peak resting voltage while the cells stabilise. After one or two full discharge-and-charge cycles, the resting voltage rises into the correct band and the bar reading aligns. If the indicator still reads low after two full cycles, check that the charger completed a full green-light cycle and that pack resting voltage is at or above 7.8V before insertion.