Unitech RD650 Replacement Battery 3.7V 1100mAh 1400-900018G

Unitech RD650 / SRD650 — 3.7V Li-ion Replacement Battery (1400-900018G)

This is a 3.7V 1100mAh Li-ion battery for the Unitech RD650 and SRD650 handheld barcode scanners. It replaces OEM part numbers 1400-900018G and BP08-000780. Both scanner models share the same battery bay, connector, and BMS handshake protocol.

• RD650 and SRD650 compatibility: Both models run the same 3.7V power rail and use an identical battery connector with matching BMS communication lines. The same pack services either unit without modification.
• Bench tested on actual hardware: We ran this pack through charge acceptance and scan-trigger inrush cycles on the RD650 platform. The BMS responded correctly to both steady draw and burst current from the imager — no false cutoffs recorded.
• First-shift preparation for pick-and-pack use: After installing this battery, seat the scanner in its charging cradle for a full charge cycle before putting it into active use. Scan trigger inrush current peaks when the cell is near its minimum — a fully charged pack prevents false BMS trips during the first high-frequency scanning shift.

Cradle showing a charging error on a new pack

The RD650 cradle monitors contact resistance between the dock pins and the battery terminals. Residue from packaging, shipping, or handling raises that resistance above the threshold the dock uses to confirm a valid charge connection. The cradle then flags the error rather than push current into what it reads as a suspect circuit. Wipe the gold contacts on the battery with a dry lint-free cloth, reseat the scanner firmly in the cradle, and confirm the charge indicator activates within 10 seconds.

Scanner losing wireless connection mid-scan-burst

During rapid scanning, the imager and the wireless radio draw current simultaneously — the scan trigger fires inrush, and the radio holds a polling interval at the same moment. On a partially depleted cell, this combined spike can drag cell voltage below the BMS low-voltage floor, triggering a momentary cutoff that drops the wireless session. This is not a radio fault or a network issue. Charge the pack to 4.2V before the shift and keep the battery above 30% charge during high-frequency scanning runs.