About this replacement
Icom IC-A6 / IC-A24 Series — 7.2V Ni-MH Replacement Battery (BP-209)
This is a 7.2V, 1800mAh nickel-metal hydride replacement battery for the Icom IC-A6, IC-A6E, IC-A24, IC-A24E, and over 31 additional Icom handheld aviation transceiver models. It replaces OEM part numbers BP-209, BP-209N, BP-210, BP-210N, BP-222, and BP-222N. The physical dimensions are 120.60 × 54.00 × 36.35mm — check yours before ordering if you are unsure which pack your radio uses.
- IC-A6 and IC-A24 platform fit: These models share the same battery bay geometry, contact rail spacing, and BMS handshake protocol. A single pack covers the full series because Icom standardised the connector and voltage rail across the IC-A aviation line when it moved from the original BP-209 to the BP-209N revision.
- Bench tested on actual hardware: We ran this pack through charge and transmit cycles on the IC-A6 platform. The BMS accepted the dock charge without a fault condition, and the transmit current spike on PTT did not trip the overcurrent threshold.
- First insertion into the charger dock: If the dock LED blinks fault on the first seating, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Icom aviation charger requires a clean contact cycle to complete the BMS handshake before it will begin the charge sequence.
Why the IC-A6 drops to reduced TX power mid-session on a new battery
Ni-MH cells ship at storage voltage — typically 1.1–1.2V per cell — not full charge. The IC-A6 monitors pack voltage under transmit load and steps down RF output when it sees sustained sag below its threshold. This is not a fault with the replacement pack; it is the radio protecting its PA stage. Run a full charge cycle first, then allow the cells to reach operating temperature before extended use in cold cockpit environments.
Bar indicator showing one fewer bar than expected after fitting a new pack
The IC-A6 and IC-A24 use a voltage-threshold bar indicator, not a fuel gauge chip. A new Ni-MH pack at storage voltage will read one or two bars below full even though the cells are not depleted. Charge the pack fully in the Icom dock until the LED goes solid green. After a complete charge, the bar display will read accurately against actual cell voltage.