Vertex Standard FNB-112Li 7.4V Compatible Battery 2600mAh

Vertex Standard VX-260 / EVX-530 Series — 7.4V Li-ion Replacement Battery (FNB-112Li)

This 7.4V, 2600mAh Li-ion battery replaces the FNB-112Li and FNB-113Li packs used in the Vertex Standard VX-260, VX-261, EVX-530, and EVX-531 two-way radios. It matches the original form factor and connector, and the BMS communicates with the same voltage thresholds the radio expects. OEM part numbers AAJ67X001 and AAJ68X001 are also covered by this pack.

• VX-260 / EVX-530 platform fit: The VX-260, VX-261, EVX-530, and EVX-531 share the same battery bay dimensions, locking rail, and contact strip. The BMS handshake uses the same voltage-threshold protocol across all four models, so one pack covers the full group without modification.
• Bench tested on actual hardware: We cycled this pack through full charge-discharge runs on the VX-261 and EVX-530. The BMS held the 6.0V low-cell cutoff cleanly on both units and accepted charge without a fault LED on the first dock insertion.
• First insertion on a Vertex charger dock: If the dock shows a fault LED on first seating, remove the battery and wipe the gold contact strip with a dry cloth before reseating. The Vertex platform requires a clean contact cycle to accept the new BMS handshake — a partial contact trace is usually the cause, not a bad cell.

Why the VX-260 cuts out mid-transmission on a new FNB-112Li

The VX-260 draws a sharp current spike the instant PTT is pressed — transmit current can jump from under 200mA in standby to over 1.5A in under 50 milliseconds. A new pack arriving at storage voltage (around 3.7V per cell) has higher internal impedance than a conditioned cell. The BMS can trip its overcurrent protection during that spike, cutting the radio mid-transmission rather than after it. One full charge cycle drops cell impedance enough that the BMS no longer trips on PTT. After the first full charge, retest by pressing PTT from standby — if the cutout stops, the pack is fine.

Bar indicator showing one fewer bar than expected on a new pack

The VX-260 and EVX-530 read battery level by measuring pack voltage against fixed thresholds — there is no fuel-gauge chip counting capacity. A new cell shipped at storage voltage (roughly 3.65–3.75V per cell, 7.3–7.5V pack) sits just below the top threshold, so the radio displays three bars instead of four. This is a voltage reading, not a capacity fault. Charge the pack fully to 8.4V and the indicator will move to four bars on next power-on.