About this replacement
Unitech PA768 Rugged Mobile Computer — 3.85V Li-ion Replacement Battery (1400-900069G)
This 3.85V, 5100mAh Li-ion battery replaces part number 1400-900069G in the Unitech PA768 and PA768 Rugged Mobile Computer. The PA768 is a handheld barcode scanner used in warehouse, logistics, and retail pick-and-pack operations. Voltage and capacity match the original pack so the device BMS accepts the new cell without reconfiguration.
- PA768 and PA768 Rugged compatibility: Both variants share the same 3.85V battery rail, identical connector pinout, and the same BMS communication protocol. One part number covers both — no adapter or firmware change needed.
- Bench tested on actual hardware: We cycled this pack through full charge and discharge on the PA768 and monitored BMS handshake at startup. The protection circuit responded correctly to over-current and low-voltage cutoff thresholds on every cycle.
- First-shift cradle charge: After installing, place the PA768 in its charging cradle for a full cycle before starting work. Scan trigger inrush current peaks when the cell is near minimum charge, and a fully charged pack prevents false BMS trips the first time the trigger is pulled in a heavy scan burst.
Why the PA768 drops its wireless connection during rapid scan bursts
The PA768 draws power from two simultaneous loads during active scanning — the imager and the wireless radio. A rapid scan burst pulls the combined inrush from both at once. If the cell voltage sags below the radio module's minimum operating threshold mid-burst, the radio drops out before the scanner does. A fresh, fully charged cell holds voltage under that combined load where a degraded cell cannot.
Cradle showing a charging error after fitting the new pack
A charging error on the cradle dock immediately after a battery swap almost always traces to contact resistance, not a faulty cell. The dock contacts on the PA768 cradle and the battery pack's gold contacts both collect oxidation and debris during warehouse use. Wipe the contacts on both the pack and the cradle with a dry lint-free cloth, then reseat the scanner firmly until it clicks. If the error clears, the pack was not at fault — the dock contacts were the gap. Target a dock contact resistance below 0.1 ohm for stable charge initiation.