About this replacement
VeriFone iPay E355 — 3.8V Li-ion Replacement Battery (BPK087-500)
This is a 3.8V 1950mAh Li-ion battery for the VeriFone iPay E355 mobile payment terminal. It replaces OEM part BPK087-500 and BPK087-500-01-A. The E355 is a portable POS device used by merchants to process card payments wirelessly at counters, tables, and mobile sales environments.
- iPay E355 and e355 compatibility: Both model designations refer to the same hardware platform. They share the same battery bay dimensions, connector pinout, and BMS handshake protocol — this cell fits both without modification.
- Bench tested on actual hardware: We ran the E355 through card-present transaction cycles, including print and wireless bursts. The BMS accepted the cell without a fault flag, and charge IC entered top-off mode as expected on a new cell at first charge.
- First deployment tip for the E355: After installation, run at least one complete transaction cycle — payment capture through receipt print — before going live. The terminal maps battery capacity during normal operation and needs one full power cycle to calibrate the charge indicator correctly.
Terminal not completing PCI boot sequence after battery swap
The E355 runs a PCI security boot check on every power-on. If the battery voltage is below the terminal's acceptance threshold, the boot sequence stalls before the OS loads. A new cell shipped in storage state may sit at 3.4V or lower. Connect the terminal to the VeriFone charger and allow it to reach at least 3.6V before attempting to boot. One full charge cycle usually resolves the stall permanently.
Battery indicator stuck at 99% on the E355 display
This is a charge IC behaviour on new lithium cells, not a fault. The E355's charge controller enters a top-off phase near full capacity and holds the displayed percentage until the cell voltage stabilises at 4.2V. The indicator stays at 99% during this phase, which can last 20–40 minutes on a fresh cell. Once the charge IC exits top-off mode and the terminal completes one full discharge-charge cycle, the percentage display tracks normally. No action needed beyond that first cycle.