About this replacement
Sunmi V2S / V2S Plus — 7.7V Li-ion Replacement Battery (JKPJ)
This is a 7.7V 3500mAh Li-ion replacement battery for the Sunmi V2S and V2S Plus handheld POS terminals. It uses OEM part number JKPJ and fits directly into both models. These devices are widely used in retail and logistics for barcode scanning and point-of-sale transactions, so a degraded cell hits productivity fast.
- V2S and V2S Plus compatibility: Both models run the same 7.7V battery rail with the same connector and BMS handshake protocol. One pack covers either unit in your fleet without modification.
- Bench tested on actual hardware: We ran this pack through repeated scan-trigger and wireless polling cycles. The BMS held stable under combined inrush loads and did not trip during back-to-back burst scanning.
- First-shift preparation: After installing, seat the scanner in its cradle and run a full charge cycle before use. Scan-trigger inrush is highest when the cell is near minimum charge, and starting the first shift on a full cell prevents false BMS trips during peak pick-and-pack loads.
Why the V2S loses wireless connection during rapid scan bursts
The V2S draws current simultaneously from the imager, the CPU, and the wireless radio during a scan burst. On a degraded or deeply discharged cell, that combined load causes a momentary voltage sag below the radio module's minimum operating threshold. The radio drops out to protect itself, and the connection breaks mid-session. A fully charged, healthy cell maintains voltage above 7.2V under this combined load and keeps the radio stable.
Cradle showing a charging error after fitting the new pack
This usually points to high contact resistance between the battery terminals and the cradle's charging contacts, not a fault with the pack itself. Dust, oxidation, or a film of residue on the gold contacts breaks the circuit the dock uses to detect the pack. Wipe the battery terminals and the cradle contacts with a dry lint-free cloth, then reseat the scanner firmly until it clicks. If the error clears within 30 seconds, contact resistance was the cause.