About this replacement
Yaesu VR-120 / VR-120D — 2.4V Ni-MH Replacement Battery (FNB-79)
This is a 2.4V 1500mAh Ni-MH replacement battery for the Yaesu VR-120 and VR-120D handheld receivers. It uses the OEM part number FNB-79 and fits the original battery compartment without modification. Capacity figures come from product data — 1500mAh at 3.6Wh.
- VR-120 and VR-120D fit: Both models share the same 2.4V two-cell Ni-MH pack format and identical battery compartment dimensions. The connector pinout and cell arrangement are the same across both variants, so one part number covers both.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a VR-120 body. The battery accepted a full charge from the standard Yaesu desk charger and held voltage within expected Ni-MH discharge curves throughout the test.
- First-insertion contact cycle on the Yaesu charger dock: If the charger shows a fault indicator on first insertion, remove the FNB-79, wipe the gold contact pads with a dry cloth, and reseat firmly. The Yaesu dock needs a clean contact surface to recognise the new pack and begin the charge cycle.
VR-120 bar indicator showing one fewer bar on a freshly inserted FNB-79
Ni-MH cells ship at storage voltage — typically around 1.1V per cell — not at full charge. The VR-120 reads pack voltage directly against fixed thresholds to drive its bar display. A new, uncharged pack will sit below the top threshold and show one or two bars instead of a full stack. This is not a fault with the cell. Run a full charge cycle first, and the indicator will read correctly at approximately 2.8V resting voltage.
Charger dock fault LED that never clears after inserting the FNB-79
A persistent fault LED usually means the pack voltage has dropped below the dock's acceptance threshold — common after long storage. The Yaesu charger checks for a minimum voltage before beginning the charge sequence; if the pack reads too low, the dock flags it rather than charging. Try a different charger if one is available, or let the radio itself draw the pack down to zero and reinsert into the dock. If voltage recovers above 2.0V after the radio discharges it, the dock should accept it and begin charging normally.