About this replacement
Socket Mobile S860 / D840 / D860 / DS800 — 3.7V Li-Polymer Replacement Battery (FT623042P)
This is a 3.7V, 600mAh Li-Polymer replacement for the OEM FT623042P battery cell. It fits the Socket Mobile S860, D840, D860, DS800, and six additional models in that same scanner family. The physical dimensions are 42.20 × 30.80 × 5.50mm — verify against your existing cell before installing.
- S860 / D840 / D860 / DS800 platform fit: These scanners share the same battery bay geometry, connector pinout, and BMS handshake protocol. A single cell revision covers the full range without modifications to the housing or contacts.
- Bench tested on actual hardware: We cycled this cell through repeated scan-burst and wireless polling loads on the S860. The BMS held stable across the full discharge curve and cut off cleanly at the low-voltage threshold without latching faults.
- First-shift preparation: After installing, seat the scanner in its cradle and complete a full charge cycle before putting it into active use. Scan trigger inrush is highest when the cell sits near minimum charge, and a fully charged cell prevents false BMS trips on the first pick-and-pack shift.
Cradle showing a charging error on a freshly installed pack
New Li-Polymer cells ship at a storage charge — typically around 3.7V to 3.85V — not a full 4.2V. Some Socket Mobile cradles interpret an unfamiliar charge state on a new pack as a fault and display a charging error LED. The fix is nearly always mechanical: wipe the gold contacts on the battery and the cradle dock with a dry cloth, reseat the scanner firmly, and let the charge cycle restart. If the error clears within 60 seconds of reseating, the cell is fine.
Scanner dropping wireless connection during rapid back-to-back scans
Each scan trigger pull draws a short inrush current spike at the same moment the wireless radio is polling the host. On an aged or deeply discharged cell, this combined draw causes a momentary voltage sag below the BMS protection floor, and the radio resets to recover. This replacement cell's 600mAh capacity maintains a flatter discharge curve under the combined load. If dropouts persist after a full charge, check that the battery contacts are seated flush — even 0.5mm of misalignment raises contact resistance enough to worsen sag.