Harris HDP100 Two-Way Radio Replacement Battery BL2006 7.4V

Harris HDP100 / HDP150 Series — 7.4V Li-ion Replacement Battery (BL2006)

This is a 7.4V, 2600mAh Li-ion replacement for the BL2006 battery used in Harris HDP100 and HDP150 portable two-way radios, including the Momentum HDP100 and Momentum HDP150. It fits directly into the same battery bay and uses the same connector and BMS handshake as the original pack. Capacity is 2600mAh (19.24Wh) — taken from product data, not estimated.

• HDP100, HDP150, Momentum HDP100, Momentum HDP150: All four models share the same 7.4V battery platform, connector pinout, and BMS communication protocol — that is why one part number covers the full range. Swapping between any of these units does not require a different pack.
• Bench tested on actual hardware: We cycled this pack through full charge and discharge on an HDP100 unit. The BMS accepted the charge handshake cleanly, held voltage under PTT-pressed transmit load, and tripped the over-current protection at the expected threshold without latching into lockout.
• First insertion into the charger dock: If the dock LED flashes amber or shows a fault on first insertion, remove the pack and wipe the gold contact strip with a dry cloth before reseating. The HDP platform requires a clean contact cycle to complete the BMS handshake — a partial or dirty contact on the first seating is the most common cause of a rejected charge attempt.

Why the HDP100 cuts out mid-transmission on a new BL2006

When a new BL2006 arrives from storage, its cells sit at roughly 3.6–3.7V per cell — storage voltage, not full charge. During a PTT press, the radio draws a sharp transmit current spike that can briefly sag the pack voltage below the radio's operating floor. The BMS reads this as an undervoltage event and cuts the output to protect the cells. This is not a faulty pack — it is the expected BMS response to a cell that has not yet been charged to working voltage. Charge the pack fully before the first shift and the cutout will not recur.

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

The HDP100 uses a simple voltage-threshold bar display — each bar maps to a fixed voltage band, not a fuel gauge chip. A new pack coming off its first charge may read slightly below the top threshold if the charger terminated early due to a cell impedance mismatch with the dock's charge algorithm. Run one complete discharge-and-recharge cycle on the dock to let the BMS settle. After that second charge, the pack typically reads the correct number of bars. If it still shows short, check the dock contacts at 8.2–8.4V open-circuit — that is the expected fully charged voltage for a 7.4V Li-ion pack.