Harris 41B025AK00201 Two-Way Radio Replacement Battery 10.8V 1200mAh

Harris 41B025AK00201 / 41B025AK00501 — 10.8V Ni-MH Replacement Battery

This is a 10.8V, 1200mAh Ni-MH battery pack built to fit Harris portable two-way radios using OEM part numbers 41B025AK00201 or 41B025AK00501. It delivers the same voltage rail and connector footprint as the factory pack. Capacity is rated at 1200mAh (12.96Wh).

• Dual OEM part number compatibility: Both 41B025AK00201 and 41B025AK00501 share the same 10.8V voltage rail, physical connector, and BMS handshake protocol. A single pack covers both variants because the electrical interface is identical across this Harris radio series.
• Bench tested on actual hardware: We cycled this pack through charge and full transmit-load discharge on the bench. The BMS handled the transmit current spike at PTT press without tripping, and the pack held voltage within spec across the discharge curve.
• Contact strip care on first dock insertion: If the charger shows a fault LED on first insertion, remove the pack and wipe the gold contact strip with a dry cloth before reseating. Harris charger docks require a clean contact cycle to complete the BMS handshake before charging begins — a partial contact read is the most common cause of a false fault on new packs.

Why a Harris radio cuts out mid-transmission on a new Ni-MH pack

Ni-MH cells ship at storage voltage, typically 30–50% of full charge. When PTT is pressed, transmit current spikes sharply and a partially charged Ni-MH pack can sag below the radio's undervoltage cutoff threshold. The BMS reads this as a fault and interrupts the transmit cycle before the message completes. A full charge cycle before first field use resolves this — the pack needs a full charge before it can handle sustained RF output without sagging.

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

Harris radios use voltage-threshold bar indicators, not percentage-based fuel gauges. A new Ni-MH pack often shows one fewer bar because the cells haven't yet stabilised their resting voltage after the first charge cycle. After one full discharge and recharge, the resting voltage rises and the indicator aligns correctly. If the indicator still reads low after two full cycles, check charger dock contact continuity — a dirty contact pad will under-charge the pack and suppress the voltage reading.