Cassidian TPH700 Compatible Battery HR7742AAA02 7.4V 2300mAh

Cassidian TPH700 / P3G — 7.4V Li-ion Replacement Battery (HR7742AAA02)

This 7.4V, 2300mAh Li-ion battery replaces the OEM pack on the Cassidian TPH700 and P3G portable two-way radios. It fits public safety, security, and enterprise radio users who run extended shifts on a single pack. Capacity figure is 2300mAh as supplied — do not rely on third-party listings that inflate this number.

• TPH700 and P3G platform fit: Both radios share the same battery bay geometry, contact pin arrangement, and 7.4V nominal voltage rail. The BMS handshake protocol is identical across both models, so one replacement pack covers either unit without modification.
• Bench tested on actual hardware: We ran this pack through charge, full-load PTT cycles, and BMS fault checks on a TPH700 dock. The BMS held the transmit current spike without tripping, and the charger dock cleared to green within the normal window.
• First insertion on the dock: If the dock shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The TPH700 dock requires a clean contact cycle to complete the BMS handshake before it will begin charging.

Why the TPH700 cuts out mid-transmission on a freshly inserted pack

A new Li-ion cell ships at storage voltage — typically 3.6–3.7V per cell, not the 4.2V peak of a full charge. When PTT is pressed, transmit current surges and the BMS detects a voltage dip that crosses its undervoltage threshold. The radio interprets this as a depleted pack and cuts TX to protect the cell. The fix is to charge the pack fully before the first operational use — the dock needs to bring both cells to 4.2V before the BMS will allow sustained transmit current.

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

The TPH700 uses a voltage-threshold bar indicator, not a fuel gauge chip. Each bar maps to a fixed voltage band. A new pack that has not completed its first full charge cycle sits at storage voltage, which lands in a lower threshold band than 100% charge — so the radio displays one bar fewer than expected even though the cell is not faulty. Charge the pack until the dock shows solid green, then reinsert. The indicator should move to the top threshold band at or above 8.3V resting voltage.