Yaesu AAJ67X001 EVX-530 Replacement Battery 7.4V 2600mAh

Yaesu EVX-530 Series — 7.4V Li-ion Replacement Battery (AAJ67X001)

This 7.4V 2600mAh Li-ion battery replaces the AAJ67X001 pack in the Yaesu EVX-530, EVX-531, EVX-534, and EVX-539 handheld transceivers. It restores full operating voltage to the EVX-500 platform without modification. Capacity is 2600mAh (19.24Wh), matched to the original cell specification.

• EVX-530 series platform fit: The EVX-530, EVX-531, EVX-534, and EVX-539 share the same battery bay dimensions, connector pinout, and BMS handshake protocol. One pack covers all four models because the voltage rail and contact geometry are identical across the series.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on an EVX-530 body. The BMS negotiated the charger handshake correctly on first insertion, and overcurrent protection tripped as expected during a simulated high-draw PTT burst at 7.2V under load.
• First-insertion contact check: If the dock shows a fault LED on first seating, remove the pack and wipe the gold contact strip with a dry cloth before reseating. The EVX platform requires a clean contact cycle to complete the BMS handshake — a partial contact on the first insert is enough to block charging from starting.

Why the EVX-530 cuts out mid-transmission on a freshly charged pack

The EVX-530 draws a sharp current spike the moment PTT is pressed — transmit current can jump to 1.5–2A within milliseconds. If the cell voltage is already sitting near the BMS low-cutoff threshold (around 6.0V under load for a 7.4V Li-ion pack), that spike is enough to trip the protection circuit and kill power mid-transmission. This is a BMS overcurrent or undervoltage event, not a defective radio. A new pack at storage voltage (typically 3.7–3.8V per cell) is more vulnerable to this on the very first charge cycle because cells have not yet reached full resting voltage. Charge the pack completely before the first use — check for a solid green dock LED before pulling it for a shift.

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

The EVX-530 reads battery level using voltage thresholds, not a chip that tracks charge history. A new cell fresh from storage sits at roughly 3.75V per cell — below the threshold the radio maps to a full four-bar reading. After the first complete charge cycle the resting voltage rises to around 4.1–4.2V per cell, and the bar indicator catches up. If the indicator still reads low after a second full charge, check that the dock contact pins are seating cleanly and delivering a full charge termination — a dirty pin can cause the charger to terminate early at around 8.1V instead of the correct 8.4V.