About this replacement
Urovo RFG91 / RFG91 UHF-RFID — 3.7V Li-ion Replacement Battery (NB49RFG91)
This 3.7V, 4900mAh Li-ion battery replaces the OEM NB49RFG91 pack in the Urovo RFG91 and RFG91 UHF-RFID handheld scanners. Both devices run the same voltage rail and use identical connector and BMS handshake, so one pack covers both variants. The RFG91 UHF-RFID variant draws additional current during RFID read cycles, but this 18.13Wh cell handles that load without triggering cutoff under normal polling rates.
- RFG91 and RFG91 UHF-RFID compatibility: Both models share the same battery bay, connector pinout, and BMS communication protocol. The UHF-RFID variant pulls slightly more current during tag reads, but the protection circuit on this pack is rated for those inrush spikes without nuisance tripping.
- Bench tested on actual hardware: We cycled this pack through repeated scan-trigger events and UHF read bursts on the bench. The BMS held a stable output voltage and did not enter sleep or cutoff during simulated high-frequency scan sequences.
- First-shift preparation: After installing, place the scanner in its cradle for a full charge cycle before use in pick-and-pack. Scan trigger inrush current is highest when the cell is near minimum charge, and starting from full capacity prevents false BMS trips during the first shift.
Cradle showing a charging error on a new NB49RFG91 pack
A new pack fresh from packaging often reads 3.2–3.4V — below the threshold some Urovo cradles expect before they initiate a charge handshake. The dock may flag an error or show a fault LED instead of a charge indicator. This is a storage-voltage condition, not a defective cell. Place the scanner directly in the cradle, leave it undisturbed for 10–15 minutes, and the BMS will complete the handshake once the cradle's pre-charge pulse raises the cell above 3.5V.
Scanner losing wireless connection during rapid scan bursts
During rapid successive scans, the RFG91 draws current simultaneously from the imager, the wireless radio, and the scan trigger. Combined inrush can cause a momentary voltage sag at the battery terminals. If that sag drops below the radio module's minimum operating voltage, the wireless link drops before the BMS actually cuts off. Check that the battery contacts on both the pack and the device are clean and making full contact — oxidised contacts increase resistance and worsen the sag. If the issue persists on a fully charged pack, wipe the gold contact pads with a dry cloth and reseat the battery until it clicks.