Sunmi M1 Barcode Scanner Replacement Battery W5910 3.8V

Sunmi M1 — 3.8V Li-Polymer Replacement Battery (W5910)

This is a 3.8V, 3000mAh Li-Polymer battery that fits the Sunmi M1 mobile barcode scanner. The M1 is a handheld data collection device used in retail, warehouse picking, and point-of-sale environments. It replaces part number W5910 directly.

• M1 platform fit: The M1 uses a Li-Polymer cell at 3.8V nominal to power the imager, wireless radio, and Android OS simultaneously. The connector pinout and BMS handshake on this pack match the original W5910 spec, so the device firmware recognises the battery and reports charge state correctly.
• Bench tested on actual hardware: We cycled this pack through repeated scan-trigger bursts while the Wi-Fi radio was active. The BMS held voltage above the low-threshold cutoff without tripping during combined inrush from both the imager and the radio stack.
• First-shift charging tip: After installing, seat the scanner in its cradle and run a full charge cycle before using it on the floor. Scan trigger inrush current peaks when the cell is near minimum charge — starting a shift on a full cell prevents false BMS trips during the first heavy pick run.

Cradle showing a charging error on a new pack

A charging error on a new pack almost always comes from contact resistance at the dock pins, not a fault in the battery itself. Oxidation or debris on the gold contacts raises resistance enough that the cradle's charge controller reads an open circuit. Wipe the contacts on both the pack and the cradle with a dry cloth, then reseat the scanner firmly. If the error clears, the pack was fine — the dock was the problem.

Scanner losing wireless connection during rapid scan bursts

During a fast scan burst, the imager and Wi-Fi radio draw current simultaneously. If the cell voltage sags under that combined load, the radio stack drops its connection before the imager does — so the scanner reads the barcode but fails to transmit. This is a voltage-sag symptom, not a Wi-Fi fault. Check the battery charge level first; if the cell is below 3.6V under load, charge the pack fully and retest before assuming a network or radio issue.