About this replacement
Pax N910 / N900 / N510 — 7.4V Li-ion Replacement Battery (YW-002)
This is a 7.4V, 2600mAh Li-ion battery for the Pax N910, N900, and N510 mobile payment terminals. It fits the battery bay directly and connects to the terminal's onboard charge IC. Voltage and capacity match the OEM spec — 7.4V, 2600mAh (19.24Wh).
- N910, N900, and N510 compatibility: These three Pax terminals share the same battery bay dimensions, connector pinout, and BMS handshake protocol. One cell fits all three without modification.
- Bench tested on actual hardware: We cycled this battery on the N910 and monitored BMS communication during boot, transaction load, and receipt print events. The protection circuit responded correctly to the printer motor's current spike without tripping an overcurrent fault.
- First transaction cycle before live deployment: After installation, run one complete transaction — including a receipt print — before putting the terminal into service. The N910 maps battery capacity during normal operation and needs at least one full power cycle to display the charge indicator accurately.
Terminal not completing PCI boot sequence after battery swap
The Pax N910 runs a PCI-compliant boot sequence that includes a BMS handshake before the OS fully loads. A new cell sometimes stalls this handshake on the first boot because the BMS has not yet synchronised its state registers with the terminal's charge IC. The fix is straightforward: let the terminal complete its first full boot with the new battery installed and mains power connected. If the terminal hangs at the Pax logo, hold the power button for 10 seconds to force a hard reboot — the second boot attempt completes the handshake in almost all cases.
Battery indicator stuck at 99% after first charge
On a new Li-ion cell, the N910's charge IC enters a top-off phase once the cell reaches approximately 4.15V per cell. During this phase the indicator holds at 99% for an extended period — this is normal charge controller behaviour, not a fault. The indicator moves to 100% once the current tapers below the charge IC's termination threshold, typically at or below 100mA. No action is needed; leave the terminal on charge until the indicator updates on its own.