Unitech HT660 Replacement Battery 3.7V 3600mAh

Unitech HT660 / PA600 / PA950 Series — 3.7V Li-ion 3600mAh Replacement Battery

This is a 3.7V 3600mAh Li-ion battery for the Unitech HT660, PA600, PA950, and PA966 handheld barcode scanners. These terminals are used in warehouse, retail, and logistics environments where the scanner runs through full shifts of continuous barcode reads and wireless data transmission. This pack replaces cells that have degraded to the point where they can no longer sustain a working shift.

• HT660 / PA600 / PA950 / PA966 platform fit: These models share the same 3.7V cell format and battery contact layout. The BMS on each device expects the same charge termination voltage and protection thresholds, so one pack covers the whole group.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the HT660 platform. The BMS accepted the cell without fault codes, and protection circuitry responded correctly to overvoltage and undervoltage cutoff points.
• First-shift preparation for pick-and-pack use: Place the scanner in its cradle for a full charge cycle before the first shift. Scan trigger inrush current peaks when the cell is near minimum — a fully charged pack prevents false BMS trips during the first burst of rapid scanning.

Cradle showing charging error on a new pack

Charging docks on the HT660 and PA series use contact pins that corrode or collect debris from warehouse environments. When a new pack seats into a dirty dock, contact resistance rises and the charger interprets the voltage drop as a fault condition. Wipe the gold contacts on both the battery and the cradle with a dry cloth before reseating. If the error clears after reseating, the dock contacts — not the battery — were the cause.

Scanner losing wireless connection during rapid scan bursts

On the HT660 and PA600, the wireless radio and scan trigger draw current simultaneously during a burst scan sequence. A degraded or deeply discharged cell cannot sustain the combined inrush, and the voltage rail sags enough to drop the wireless link. This looks like a network or Wi-Fi issue but the trigger is the battery. Charge the pack to full — 4.2V at the cell — before the shift and the voltage sag during burst scanning stays within the radio module's operating range.