About this replacement
KOAMTAC KDC-300 Series — 3.7V Li-ion Replacement Battery (KDC-BAT300)
This 3.7V, 1200mAh Li-ion cell replaces the OEM pack in the KOAMTAC KDC-300 mobile barcode scanner and fits across the KDC-250, KDC350R2, and KDC-699200 lines. It matches the original form factor at 54.50 × 34.60 × 5.90mm, so it seats fully in both the scanner body and charging cradle. Capacity is sourced from product data at 4.44Wh — no guesswork.
- KDC-300 / KDC-250 / KDC350R2 platform fit: These models share the same battery bay dimensions, connector pinout, and BMS communication protocol, which is why a single cell covers the whole family. The handshake between the pack and the scanner's firmware relies on matching cell chemistry and voltage curve — a Li-ion cell at 3.7V nominal satisfies that requirement across all listed variants.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a KDC-300 unit, monitoring BMS cutoff behaviour at both the low-voltage floor and the charge termination ceiling. The protection circuit triggered cleanly at expected thresholds — no false trips during simulated scan-burst inrush events.
- First-shift cradle protocol: After installing this pack, place the scanner in its cradle for a complete charge cycle before running a pick-and-pack shift. The scan trigger draws a sharp inrush current — highest when the cell is near minimum — and a fully charged cell prevents the BMS from tripping on the very first scan sequence of the day.
Cradle showing a charging error on a new KDC-BAT300 pack
New packs sometimes arrive with surface oxidation on the gold contact pads, and the KDC cradle is sensitive to contact resistance at the charge port. Even a thin film of oxidation or handling residue is enough to break the handshake between the dock and the battery's protection circuit. Wipe both the pack contacts and the cradle pins with a dry lint-free cloth before reseating. If the error clears after reseating, the cell was fine — the contact was the fault.
Scanner losing wireless sync during a rapid barcode scan burst
The KDC-300 draws power simultaneously from the wireless radio and the scan trigger during a fast scan sequence. On a degraded or deeply discharged cell, this combined inrush pulls the cell voltage below the BMS protection threshold, causing the radio stack to drop its connection. The BMS interprets the combined load as a fault event and cuts output momentarily. Charge the pack fully before a high-volume shift — the radio stays stable when cell voltage is above 3.6V at rest.