Symbol PDT6800 Barcode Scanner Replacement Battery 6V 2400mAh

Symbol PDT6800 / PDT6840 Series — 6V Li-ion Replacement Battery (21-17900-01)

This is a 6V 2400mAh Li-ion battery for the Symbol PDT6800, PDT6810, PDT6840, and TR1285 handheld barcode scanners. It replaces OEM part numbers 21-17900-01, 21-38796-01, 21-52228-02, and related variants across the PDT68xx platform. The cell fits the same battery bay and uses the same contact layout as the factory pack.

• PDT68xx platform compatibility: The PDT6800, PDT6810, and PDT6840 share the same 6V battery bay and BMS handshake protocol. All three models draw from the same voltage rail, so a single battery spec covers the full lineup without connector or firmware conflict.
• Bench tested on actual hardware: We ran this pack in a PDT6840 cradle and monitored BMS response through a full charge cycle. The protection circuit held cutoff at the correct thresholds and charge termination triggered cleanly at full capacity with no false trips.
• First-shift preparation on pick-and-pack lines: After installing this battery, seat the scanner in its cradle and run a complete charge cycle before the first scan burst. The laser or imager inrush current is highest when the cell is near minimum voltage — a fully charged cell prevents the BMS from tripping on the first heavy scan sequence of the shift.

Cradle showing a charging error on a new pack

The PDT68xx cradle reads the battery through spring-loaded dock contacts. Oxidation or handling residue on the battery's contact pads raises resistance enough for the dock to report a fault before the charge cycle starts. Wipe the gold contacts on both the battery and the cradle with a dry lint-free cloth, then reseat the scanner firmly until it clicks. If the error clears, the dock was reading a high-resistance contact — not a defective cell. If the error persists after cleaning, check cradle firmware for required OEM battery authentication flags.

Scanner losing wireless connection during rapid scan bursts

On the PDT68xx, the wireless radio and the scan trigger fire simultaneously during rapid sequential scanning. That combined inrush can cause a momentary voltage sag if the cell is below 5.4V. When voltage sags past the radio module's operating floor, the wireless stack drops its access-point association before the BMS registers a low-battery event. If drops occur mid-shift rather than at end-of-shift, check cell voltage at the contacts — if it reads below 5.6V under load, the cell is due for replacement. A fresh cell at full charge holds the rail stable through both radio and imager draw without sag-induced disconnects.