Panasonic VL-2330/HFN 3V Car Key Remote Replacement Battery 50mAh

Panasonic VL-2330/HFN — 3V Lithium Vanadium Pentoxide Replacement Battery

This is a Panasonic VL-2330/HFN 3V lithium vanadium pentoxide cell rated at 50mAh (0.15Wh). It fits keyless entry fobs that take the VL-2330 cell format. The coin cell measures 23.60 x 23.60 x 9.50mm — confirm this matches the cell in your fob before ordering.

• VL-2330 fob compatibility: Keyless entry fobs using the VL-2330 format share a specific voltage requirement and form factor. Lithium vanadium pentoxide holds a stable 3V output through most of its discharge curve, which suits the RF transmission pulses the fob sends on each button press.
• Bench tested on actual hardware: We cycled the cell through repeated RF pulse loads representative of fob button presses. Voltage held steady above 2.8V through the majority of discharge, dropping sharply only near end of charge — consistent with the vanadium pentoxide chemistry spec.
• Rolling code re-sync after swap: After fitting the new cell, stand within one metre of the car and press the lock button five times in quick succession. Power interruption during the swap causes a rolling code mismatch — this step re-syncs the fob to the car's receiver module.

Car key fob not unlocking the car after battery swap

Replacing the cell cuts power to the fob's microcontroller, which resets its rolling code counter. The car's receiver module keeps advancing its own counter while the fob is dead, so after swap the two counters are out of step. Most systems allow a re-sync window — stand close to the car and press lock five times consecutively. If that fails, check the replacement cell is seated positive-side up and reads at least 2.9V under load.

Push-button start not recognising fob after battery swap

Some push-button start systems require a stronger signal than a critically low or newly seated cell delivers at storage voltage. If the car won't recognise the fob in your pocket, hold the fob body directly against the start button — most systems have a passive RFID fallback that reads the fob's transponder chip at close range without needing battery power. If this gets the car started, the fob battery is likely the culprit and the cell voltage should recover to full output after a few normal uses from storage.