About this replacement
Tactilion G3 / G870 / K370 — 7.4V Li-ion Replacement Battery (GX01)
This 7.4V 1750mAh Li-ion battery replaces the OEM GX01 cell in Tactilion G3, G870, and K370 payment terminals. All three models run on the same voltage rail and share an identical physical form factor and connector. Capacity is rated at 12.95Wh — matching the original specification for these terminals.
- G3, G870, and K370 compatibility: These three terminals share the same battery bay dimensions, connector pinout, and BMS communication protocol. A single GX01-spec cell covers all three without modification.
- Bench tested on actual hardware: We ran this cell through full charge cycles on a G3 unit, monitoring BMS handshake acceptance, charge IC behaviour during top-off, and cutoff response under combined display, printer, and wireless draw. The BMS accepted the cell within the first complete boot-charge cycle.
- First deployment tip for POS terminals: After installing the battery, complete one full transaction cycle — including a receipt print — before deploying in a live environment. The terminal maps battery capacity during normal operation and requires at least one complete power cycle to calibrate the charge indicator accurately.
Receipt printer causing battery drain on the G3 and K370
The thermal printer inside these terminals draws a sharp current spike each time it fires — typically the highest single load event the battery handles. On a degraded cell, this spike can sag the voltage enough to trip the BMS overcurrent protection and reboot the terminal mid-receipt. A fresh GX01-spec cell with full capacity handles this spike without voltage sag. If the terminal still reboots during printing after a battery swap, check that the charge IC has completed a full top-off cycle before blaming the cell.
Terminal not completing PCI boot sequence after battery installation
The G3 runs a PCI security boot sequence on startup that requires a stable, verified power source. A brand-new cell can fail this check if the BMS handshake hasn't been accepted yet — the terminal interprets an unverified battery as an unstable supply and halts boot. This is not a faulty battery. Connect the terminal to the charger, allow one full charge cycle to complete, then power on again. The BMS handshake completes during that first charge and the boot sequence proceeds normally from that point.