Unitech HT680 Barcode Scanner Replacement Battery 3.7V 2200mAh

Unitech HT680 / PA690 Series — 3.7V Li-ion Replacement Battery (1400-900001G)

This 3.7V Li-ion cell at 2200mAh replaces the factory battery in the Unitech HT680, PA690, HT682, and PA692 handheld barcode scanners, along with 40+ additional compatible models. It matches the original connector, form factor, and BMS handshake so the device powers on without configuration changes. Install it, charge it fully in the cradle, and the scanner returns to normal operation.

• HT680 / PA690 platform fit: These four models share the same battery bay geometry, 3.7V power rail, and BMS communication protocol. One cell covers the full range without adapter modifications or firmware workarounds.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the HT680 platform and confirmed the BMS handshake completes correctly, charge termination triggers at the right threshold, and the cell holds voltage under the combined load of the scan trigger and wireless radio.
• First-shift cradle protocol: After installing a new cell, place the scanner in its cradle for a full charge cycle before starting a pick-and-pack shift. The scan trigger inrush current peaks when the cell is near minimum charge, and a fully charged pack prevents false BMS trips during the first heavy-use period.

Cradle showing charging error on a new pack

A charging error on a freshly installed pack is almost always a contact resistance problem, not a faulty cell. Dock contacts on high-cycle cradles accumulate oxidation and debris that interrupt the low-current handshake the HT680 cradle uses to identify and begin charging a pack. 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 and charging begins, the cell itself was never the issue.

Scanner losing wireless connection during rapid scan bursts

During a rapid scan sequence, the HT680 draws current simultaneously from the imager, the wireless radio, and the processor — peak combined inrush can briefly sag cell voltage below the BMS low-voltage threshold. When this happens, the BMS interrupts output to protect the cell, and the wireless stack drops its connection before the device recovers. A cell that is already partially discharged or has accumulated capacity fade is most vulnerable to this voltage sag. Keep the pack above 50% charge during high-frequency scanning shifts, and replace any cell that triggers this symptom consistently above 3.5V under load.