About this replacement
Wiseasy P3 / WPOS3 Series — 3.7V Li-ion Replacement Battery (BT-O1)
This is a 3.7V, 6000mAh Li-ion replacement for the original BT-O1 battery. It fits the Wiseasy P3, WPO3, WPOS3, and WPOS-3 portable payment terminals. These are compact POS devices used in retail and hospitality for wireless card and transaction processing.
- P3 and WPOS3 platform compatibility: The P3 and WPOS3 share the same battery bay geometry, connector pinout, and BMS communication protocol. One cell covers the full range of these terminals without modification.
- Bench tested on actual hardware: We ran this cell through a full boot sequence on a WPOS3 unit. The BMS handshake completed correctly, the charge IC accepted the cell, and the terminal reached the payment processing screen without fault flags.
- First deployment tip for payment terminals: After installation, complete one full transaction cycle before going live. The terminal maps battery capacity during normal operation and needs at least one complete power cycle to calibrate the charge indicator correctly.
Terminal rebooting mid-transaction after battery swap
The P3 terminal draws a sharp current spike when the built-in receipt printer fires. On a new or deeply discharged cell, the BMS can read this spike as an overcurrent event and trip the protection circuit, cutting power mid-transaction. This is a BMS calibration issue, not a faulty battery. Run two or three complete transaction cycles including printed receipts and the BMS will recognise the printer load as normal operating behaviour and stop tripping. If it continues after five cycles, check that the battery connector is fully seated — a loose connection amplifies voltage sag at the BMS sense pin.
Terminal stuck on boot screen after sitting unused for weeks
A terminal left in a drawer will self-discharge below the BMS recovery threshold — typically under 2.5V per cell — and the protection circuit will lock the output to prevent damage. The terminal shows no response or loops on the boot screen because it cannot draw enough voltage to complete the PCI initialisation sequence. Connect the original charger and leave the terminal on charge for a full 90-minute recovery pass before attempting to power on. Once the cell climbs back above 3.0V, the BMS releases the lock and the terminal boots normally.