Honeywell SG20 Barcode Scanner Replacement Battery 3.7V 1600mAh

Honeywell SG20 — 3.7V Li-ion Replacement Battery

This 3.7V 1600mAh Li-ion battery is a direct replacement for the Honeywell SG20 handheld barcode scanner. It fits the SG20 used in retail, warehousing, and logistics environments for mobile data collection. Swap it in when the original cell no longer holds a usable charge across a full shift.

• SG20 platform fit: The SG20 uses a compact 3.7V single-cell pack with a dedicated BMS that monitors cell voltage and temperature. This replacement matches that voltage rail and connector configuration so the scanner's power management system recognises the pack without throwing a fault.
• Bench tested on actual hardware: We cycled this pack through scan-trigger and wireless radio draw simultaneously on the bench. The BMS held regulation through repeated inrush events and did not trip under combined load typical of rapid pick-and-pack scanning sessions.
• First-install charging tip: After installing, seat the scanner in its cradle and run a full charge cycle before the first shift. Scan trigger inrush is highest when the cell sits near minimum voltage — a pre-charged pack prevents the BMS from tripping on the first burst of the day.

Cradle showing a charging error on a new pack

A charging fault on the dock does not always mean the battery is defective. Dock contacts on the SG20 cradle accumulate oxidation and debris, which raises contact resistance high enough that the charger circuit sees an incomplete connection and throws an error. Remove the scanner, wipe the gold contacts on both the battery and the cradle with a dry lint-free cloth, then reseat firmly. If the error clears, the pack is charging normally — confirm with a cradle LED showing solid charge status.

Scanner loses wireless connection during rapid scan bursts

The SG20 runs its wireless radio and scan imager simultaneously, and both draw current at the same moment during a fast scan event. If the cell voltage sags under that combined load, the radio module drops its connection before the BMS trips — the scanner may still appear powered but loses its network link. This is more common when a degraded or deeply discharged cell cannot sustain voltage under the peak draw. Fully charge the replacement pack before use and check that the scanner reconnects cleanly at full charge — connection should restore without manual re-pairing.