About this replacement
Kenwood TH-D7A / TH-G71A Series — 7.2V Ni-MH Replacement Battery (PB-39)
This is a 7.2V 1100mAh Ni-MH replacement battery for the Kenwood TH-D7A and TH-G71A dual-band handheld transceivers. It also fits the TH-D7E and TH-G71E variants. OEM part numbers replaced: PB-39, PB-39H, and PB-38.
- TH-D7 and TH-G71 platform fit: Both the TH-D7 and TH-G71 series share the same battery bay dimensions, contact layout, and 7.2V rail. One pack covers both lines without modification.
- Bench tested on actual hardware: We ran this pack through full charge and transmit-load cycles on a TH-D7A. The BMS held steady through repeated PTT bursts and did not trigger overcurrent cutoff under sustained RF output.
- First insertion into the charging 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 Kenwood dock requires a clean contact cycle to complete the BMS handshake before charging begins.
Why the TH-D7A cuts out mid-transmission on a fresh pack
Ni-MH cells ship at storage voltage — typically 1.1–1.2V per cell, well below the 1.2V nominal operating point. On the TH-D7A, the transmit current spike at PTT can pull a partially charged pack below the BMS low-voltage threshold before a single exchange is complete. This is not a faulty battery. Run the pack through one full charge cycle before the first transmission test. After a full charge, the cells deliver their rated 1100mAh and handle the TX current draw without cutoff.
Bar indicator showing one fewer bar than expected after install
The TH-D7A reads pack voltage against fixed thresholds to display the bar indicator — it does not measure capacity directly. A new Ni-MH cell fresh off storage sits at a lower resting voltage than a fully charged cell, so the radio reports one bar short. This is normal behaviour, not a capacity fault. Charge the pack fully and let it rest for 15 minutes before reading the indicator — the display should step up to reflect a resting voltage above 7.8V.