About this replacement
Sunmi P2 Pro — 7.6V Li-Polymer Replacement Battery (QP1669 / ZAP1522)
This 7.6V 2400mAh Li-Polymer battery replaces the original cell in the Sunmi P2 Pro mobile payment terminal. It fits merchants running card transactions in retail, hospitality, and food service environments. Capacity is 18.24Wh — matching the original power delivery the terminal expects from its charge IC.
- P2 Pro platform fit: The P2 Pro uses a specific connector orientation and BMS handshake tied to its charge management IC. This cell carries the QP1669 and ZAP1522 part references the terminal's firmware recognises during power-on initialisation.
- Bench tested on actual hardware: We cycled this battery through the P2 Pro boot sequence and ran it through receipt printing and card reader draws. The BMS held stable under the combined wireless, display, and printer load without triggering an overcurrent cutoff.
- First deployment tip: After fitting this battery, complete one full transaction cycle — card read, receipt print, and screen-on — before live use. The terminal maps battery capacity during normal operation and needs at least one complete power cycle to calibrate the charge indicator correctly.
Payment terminal rebooting mid-transaction after battery swap
When the receipt printer fires, it pulls a short but sharp current spike. On a new cell, the BMS may read that spike as an overcurrent event before it has learned the terminal's load profile. This triggers a protective cutoff, which the terminal registers as a hard reboot. Running two or three full transaction cycles — including printed receipts — allows the BMS to establish the correct overcurrent threshold for the P2 Pro's combined draw. After those cycles, the reboot behaviour stops.
P2 Pro not powering on after sitting unused in storage
Li-Polymer cells self-discharge at roughly 1–2% per month in storage. If a P2 Pro sits unused long enough, the cell voltage drops below the BMS recovery threshold — typically around 2.5V per cell — and the terminal refuses to boot to protect the cell from damage. Connect the terminal to its original charger and leave it untouched for 30–45 minutes before pressing the power button. The charge IC needs time to trickle-charge the cell back above the 3.0V recovery floor before full charging resumes.