About this replacement
Icom IC-A25 Series — 7.4V Li-ion Replacement Battery (BP-288 / BP-289)
This 7.4V, 2350mAh lithium-ion pack replaces the BP-288 and BP-289 batteries in the Icom IC-A25 portable aircraft transceiver. It fits the IC-A25, IC-A25CE, IC-A25N, and IC-A25NE variants — all aviation handheld radios used for air-to-ground and ground communication. Voltage and connector match the original OEM specification exactly.
- IC-A25 variant compatibility: The CE and NE suffix models are regional certification variants of the same hardware platform. They share the same battery bay dimensions, contact layout, and BMS handshake protocol — which is why a single pack covers all four model numbers.
- Bench tested on actual hardware: We cycled this pack through full charge and a sustained TX load on the IC-A25 platform. The BMS held stable under the transmit current draw and did not trip into overcurrent cutoff during repeated PTT events.
- First insertion into the charger dock: If the dock LED shows a fault on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat it firmly. Aviation transceivers like the IC-A25 require a clean contact cycle for the dock to accept the new BMS handshake before charging begins.
IC-A25 transmit current spike and BMS overcurrent response
Pressing PTT on the IC-A25 pulls a sharp current spike as the RF stage powers up for transmission. A new pack at storage voltage — typically around 3.7V per cell — has higher internal impedance than a fully charged cell, which amplifies the voltage dip under that spike. If the BMS reads the dip as an overcurrent event, it will cut output momentarily. Cycling the pack through one full charge before heavy use brings cell voltage to 4.2V per cell and lowers impedance, which eliminates most BMS trips at transmit onset.
Bar indicator shows one fewer bar than expected after fitting new pack
The IC-A25 uses a voltage-threshold bar indicator — each bar maps to a voltage band, not a calculated capacity percentage. A new pack shipped at storage voltage reads in the lower bands immediately after insertion, which can look like a weak or faulty battery. This is not a fault. Charge the pack fully in the dock until the LED goes green, then power on the radio — it should read in the top voltage band at 8.4V fully charged.