About this replacement
Feitian F20 Smart POS — 7.6V Li-ion Replacement Battery (2ICP4/55/58)
This is a 7.6V, 2500mAh (19Wh) Li-ion battery for the Feitian F20 and F20 Smart POS payment terminal. It replaces OEM part 2ICP4/55/58 and fits the same battery bay without modification. Use it when the original cell no longer holds charge through a full shift of card transactions.
- F20 and F20 Smart POS fit: Both models share the same 7.6V battery bay, connector pinout, and BMS handshake protocol. The terminal reads cell voltage and state-of-charge over the same communication line, so one battery covers both variants without any firmware workaround.
- Bench tested on actual hardware: We cycled this battery through the F20 boot sequence and ran repeated transaction simulations — including receipt printer actuation and wireless data bursts. The BMS held steady through the combined current draw and did not trip an overcurrent cutoff.
- First deployment tip for the F20: After installation, complete one full transaction cycle before putting the terminal into a live queue. The F20 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
The F20 receipt printer pulls a short but sharp current spike each time it fires. On a new cell that has not yet completed a full charge-discharge cycle, the BMS can interpret this spike as an overcurrent event and cut output momentarily — causing the terminal to reboot. This is not a faulty battery. Run the terminal through two or three complete transaction cycles, including receipt prints, and the BMS learns the normal load profile. Reboots during printing stop once the cell is past its first calibration cycle.
Terminal not powering on after sitting unused in storage
Li-ion cells self-discharge slowly over weeks. If an F20 has been stored in a drawer for several months, the battery voltage may have dropped below the BMS recovery threshold — typically around 2.5V per cell. At that point the terminal will not respond to the power button because the BMS has locked output to protect the cell. Connect the terminal to its original charger and leave it for 20–30 minutes without pressing anything. Most BMS units on this cell design re-initialise once the charger pushes voltage back above 3.0V per cell, after which the terminal will boot normally.