Castles V3 Payment Terminal Compatible Battery 3.7V 2900mAh

Castles V3 / VEGA3000-3G — 3.7V Li-Polymer Replacement Battery (IP604355-2P)

This 3.7V 2900mAh lithium-polymer battery replaces the OEM cell in the Castles V3 and VEGA3000-3G portable payment terminals. It matches the original IP604355-2P specification for voltage, capacity, and connector footprint. The 59.00 × 44.10 × 11.50mm form factor seats flush in the battery bay without modification.

• V3 and VEGA3000-3G compatibility: Both terminals run on the same 3.7V cell platform and share the IP604355-2P connector pinout. The BMS on each model uses the same voltage thresholds, so one cell serves both without a firmware conflict.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the V3 platform. The BMS accepted the cell on first boot, registered charge correctly, and held voltage above the low-battery cutoff through sustained transaction loads including receipt printing and wireless activity.
• First deployment tip for POS terminals: After installation, complete one full transaction cycle — including a receipt print — before deploying in a live environment. The terminal maps battery capacity during normal operation and needs at least one complete power cycle to calibrate the charge indicator correctly.

Terminal rebooting mid-transaction after a battery swap

The V3's receipt printer motor draws a short burst of current each time it fires. On a new cell that hasn't completed a full charge cycle, the BMS can interpret this surge as an overcurrent event and trip the protection circuit — cutting power mid-transaction. This isn't a faulty cell; it's the BMS acting on incomplete calibration data. Run the terminal through one full charge and at least one complete transaction with a receipt print before going live. After that cycle, the BMS registers the printer's current profile and no longer flags it as a fault.

Terminal won't power on after sitting unused in a drawer

Li-polymer cells self-discharge at roughly 2–3% per month. Left unused long enough, the cell drops below the BMS recovery threshold — typically around 2.5V — and the terminal refuses to boot. Plug the terminal into its charge dock and leave it for 30–60 minutes before attempting to power on. If the charge LED lights, the cell is recovering. If the terminal still won't boot after a full charge attempt, check that dock voltage at the connector reads 5V before assuming the cell is at fault.