Icom BP-281 Two-Way Radio Replacement Battery 7.4V 1750mAh

Icom IC-DP2 / IC-DP2T — 7.4V Li-ion Replacement Battery (BP-281)

The BP-281 is a 7.4V, 1750mAh lithium-ion battery for the Icom IC-DP2 and IC-DP2T compact dual-band digital two-way radios. It slots into the same battery bay and connects via the same contact strip as the original Icom pack. Capacity is rated at 12.95Wh — identical to the OEM specification.

• IC-DP2 and IC-DP2T compatibility: Both models share the same voltage rail, battery bay dimensions, and BMS handshake protocol. The BP-281 communicates with the radio's charge-control circuit using the same three-contact arrangement Icom uses across this platform — the radio treats this pack as it would the original.
• Bench tested on actual hardware: We cycled this battery through simulated PTT transmit bursts and monitored the BMS response under the current spike that occurs each time the transmitter fires. The BMS held cutoff thresholds within spec and did not trigger a false overcurrent lockout during the test sequence.
• First-insertion contact cycle on the dock: If the charger dock shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat it firmly. The IC-DP2 platform requires a clean contact cycle for the dock to accept the new BMS handshake before charging begins.

Why the IC-DP2 cuts out mid-transmission on a new BP-281

Every time you press PTT, the IC-DP2 transmitter draws a sharp current spike — often two to three times the steady-state receive current. A new cell shipped at storage voltage (typically 3.6–3.75V per cell) has slightly elevated internal impedance until it completes its first full charge cycle. If the pack hasn't been fully charged before use, the BMS may read that transmit spike as an overcurrent event and cut the output for a fraction of a second. The fix is straightforward: charge the BP-281 to full before the first transmission session and the BMS will calibrate its thresholds correctly from that point forward.

Bar indicator on the IC-DP2 showing one fewer bar than expected after fitting a new pack

The IC-DP2 uses a voltage-threshold bar indicator — each bar corresponds to a specific voltage window, not a capacity percentage. A new cell at storage voltage sits below the top threshold, so the radio displays one bar fewer than a fully charged pack would show. This is not a fault with the cell. Charge the BP-281 fully in the dock and the indicator will move to the correct bar level once the cell voltage rises above 8.2V.