About this replacement
NEXGO N3 / N5 — 3.7V Li-ion Replacement Battery (GX02)
This is a 3.7V, 5100mAh Li-ion battery for the NEXGO N3 and N5 mobile payment terminals. It replaces OEM part number GX02. Both terminals share the same battery bay, connector pinout, and BMS communication protocol, so one part number covers both models.
- N3 and N5 compatibility: NEXGO built the N3 and N5 on the same hardware platform. They use an identical battery bay, matching connector, and the same BMS handshake sequence — so this cell fits both without modification.
- Bench tested on actual hardware: We cycled this battery through the full NEXGO boot sequence and monitored the BMS response during card-read, receipt print, and wireless data events. The protection circuit handled combined load spikes without tripping.
- First transaction cycle after installation: After fitting this battery, complete one full transaction — boot to receipt print — before deploying in a live environment. 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 motor fires, it draws a short current spike that can trip the BMS overcurrent threshold on a new cell if the terminal hasn't completed an initial calibration cycle. The BMS interprets the spike as a fault and cuts output, which forces a reboot mid-sale. Running one complete transaction cycle after installation — boot, card read, print — lets the BMS learn the terminal's load signature and stops false trips from occurring.
Terminal not completing PCI boot sequence after new battery installed
The NEXGO N3 runs a PCI-compliant security check on every boot. If the battery voltage sits below approximately 3.5V when the terminal first powers on, the boot sequence stalls before it reaches the payment application. A new battery shipped in storage mode may read low on arrival. Connect the terminal to the charging cradle for 15–20 minutes before the first power-on to bring the cell above the boot threshold.