NEXGO GX02 Payment Terminal Compatible Battery 3.7V 6700mAh

NEXGO N3 / N5 — 3.7V Li-ion Replacement Battery (GX02)

This is a 3.7V, 6700mAh Li-ion replacement for the GX02 battery used in the NEXGO N3 and N5 mobile payment terminals. Both terminals share the same battery bay, connector pinout, and BMS communication protocol, so a single cell covers both models. Swap it when the original cell no longer holds charge through a standard merchant shift.

• N3 and N5 shared battery platform: NEXGO built the N3 and N5 around the same power rail and BMS handshake spec. The GX02 cell fits both without any adapter or firmware change — the terminal reads cell state over the same communication line on either unit.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the N3 platform. The BMS accepted the handshake on first boot, charge IC entered CC/CV mode correctly, and protection circuits responded normally to overcurrent and overvoltage conditions.
• Post-install calibration on the N3 and N5: After fitting this cell, run the terminal through at least one complete transaction cycle before deploying it in a live environment. The charge indicator on both models maps capacity during normal operation and needs one full power cycle to display an accurate reading.

Terminal rebooting mid-transaction after a battery swap

The N3 receipt printer draws a sharp current spike — sometimes over 1.5A — each time it fires. On a new cell that has not yet completed a calibration cycle, the BMS may read that spike as an overcurrent event and trip the protection circuit. This drops the terminal mid-transaction, which looks like a crash but is actually a BMS cutoff. The fix is to run several complete transaction cycles, including printed receipts, before using the terminal in a live environment. After two or three full cycles, the BMS adjusts its load profile and the trips stop.

Terminal not powering on after sitting unused in a drawer

Li-ion cells self-discharge over time, and the N3 draws a small standby current even when switched off. After several weeks unused, the cell can drop below the BMS recovery threshold — typically around 2.5V — and the terminal will not respond to the power button. Connect the terminal to its original charger and leave it for 20–30 minutes without pressing anything. The charge IC uses a trickle pre-charge mode to bring the cell back above the recovery threshold before switching to normal CC/CV charging. Once the charge LED activates, the cell is above 2.8V and the terminal will boot normally.