About this replacement
Pax Payment Terminal — 3.85V Li-ion Replacement Battery (IDS152GA)
This is a 3.85V, 5400mAh Li-ion replacement battery carrying OEM part number IDS152GA. It fits Pax mobile point-of-sale terminals that use this cell. Voltage and capacity match the original specification exactly.
- Pax terminal power architecture: Pax mobile POS terminals run the display, contactless reader, receipt printer, and wireless radio from a single cell. The BMS on this battery manages each draw independently and will trip if any single load spike exceeds the protection threshold — most commonly during printer motor engagement.
- Bench tested on actual hardware: We cycled this battery through full charge and discharge sequences, confirmed BMS handshake acceptance, and verified that the charge IC recognized the cell without error flags or protection lockouts.
- First transaction cycle after installation: After fitting this battery, run one complete transaction from power-on through to receipt print before deploying the terminal live. The terminal maps battery capacity during normal operation and requires at least one full power cycle to calibrate the charge indicator correctly.
Receipt printer causing BMS trip during high-volume periods
The receipt printer motor draws a sharp current spike the moment it engages — far higher than the steady-state wireless or display draw. On a degraded or freshly installed battery, the BMS can interpret this spike as an overcurrent event and cut output briefly. This is more likely during back-to-back transactions when the cell temperature is already elevated. If the terminal resets consistently at print time, check that the battery contacts are clean and fully seated, and confirm the BMS has completed at least one full charge cycle on the new cell before heavy use.
Terminal won't power on after sitting unused in storage
Li-ion cells self-discharge at roughly 1–2% per month at room temperature. A terminal left in a drawer for several months can arrive with the cell below the BMS recovery threshold — typically around 2.5V per cell — at which point the BMS locks output entirely as a protection measure. Connect the terminal to its original charger and leave it for 30–60 minutes without attempting to power on. The charger applies a low-current trickle that nudges the cell voltage back above the recovery threshold, usually around 3.0V, after which normal charging resumes.