About this replacement
VeriFone T650p — 7.4V Li-ion Replacement Battery (INR18650-2S1P)
This 7.4V, 3350mAh Li-ion battery replaces the original cell pack in the VeriFone T650p portable payment terminal. It fits the T650p directly using the same connector and BMS communication protocol as the factory unit. Capacity figures come from the product data: 3350mAh / 24.79Wh.
- T650p platform fit: The T650p uses a 2S1P 18650 cell arrangement to hit the 7.4V nominal rail. The terminal's charge IC expects a specific BMS handshake on that rail — a mismatched pack will show a fault code rather than charge. This replacement uses the same cell configuration and BMS profile.
- Bench tested on actual hardware: We cycled this pack through the T650p's charge IC and confirmed the BMS handshake completed without fault codes. The protection circuit responded correctly to simulated overcurrent during a receipt-print draw spike and recovered cleanly.
- First-deployment cycle on the T650p: After fitting this battery, run one complete transaction — card tap or swipe through to receipt print — before putting the terminal into a live environment. The T650p 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 T650p runs a PCI security boot sequence on every power-on that includes a handshake with the battery BMS. On a brand-new replacement pack, the charge IC may not have completed its first acceptance cycle, causing the boot sequence to stall or loop. This is not a fault with the terminal or the battery — it is the charge IC in pre-acceptance mode. Plug the terminal into mains power, let it reach a full charge state, then cold-boot. After one complete charge cycle, the BMS handshake is accepted and the PCI sequence completes normally.
Charge indicator stuck at 99% after installing a new pack
A battery indicator locked at 99% on first charge is the T650p's charge IC operating in top-off mode on a new cell — it is not a defect. The IC holds the pack in a slow top-off phase until the cell voltage stabilises at the full-charge threshold, typically 8.40V across the 2S stack. Once that threshold is held for the required dwell time, the indicator steps to 100% and the IC switches to standby. If the indicator has not moved after 90 minutes on charge, disconnect mains, power the terminal off fully, reconnect mains, and allow a fresh charge cycle to begin from a cold state.