About this replacement
Symbol MC50 Series — 3.7V Li-ion Replacement Battery (BTRY-MC50EAB00)
This is a 3.7V, 1600mAh Li-ion battery for the Symbol MC50 and MC5040 handheld barcode scanners. It replaces OEM part numbers BTRY-MC50EAB00 and 21-67314-01. The MC50 is a rugged mobile computer used in retail, warehouse, and field service scanning operations.
- MC50 and MC5040 compatibility: Both models run on the same 3.7V single-cell platform with an identical battery bay and BMS handshake protocol, so one pack covers both. The connector pinout and physical dimensions (76.55 × 61.56 × 6.97mm) match the OEM slot exactly.
- Bench tested on actual hardware: We cycled this pack through the MC50's BMS on the bench, confirming the protection circuit communicates correctly with the device during charge, discharge, and low-voltage cutoff events. The BMS accepted the pack without throwing an error state.
- First-shift preparation: After installing, seat the scanner in its charging cradle for a full charge cycle before running pick-and-pack. The scan trigger draws peak inrush current when the cell is near minimum charge — a fully conditioned pack prevents false BMS trips on the first shift.
Cradle showing a charging error on a new pack
Cradle charging errors on a fresh pack are almost always a contact resistance problem, not a faulty battery. Warehouse cradles accumulate dust and oxidation on the dock pins over time, and a new pack with clean contacts will expose that gap. Wipe the gold contacts on the battery and the cradle dock with a dry cloth, reseat the pack firmly, and watch the charge indicator. If the error clears within 30 seconds, the contacts were the issue — not the cell.
Scanner stops reading barcodes mid-shift even though battery indicator shows charge remaining
The MC50's laser or imager draws a short, sharp current spike every time the trigger is pulled. When a cell ages and its internal resistance climbs, that spike causes a voltage sag that drops below the scanner's minimum power threshold — the imager cuts out even though the fuel gauge still reads partial charge. A new cell with lower internal resistance restores that voltage headroom. After swapping the pack, confirm the device reads barcodes consistently by running 20 rapid successive scans — if it holds through that burst, the pack is healthy.