About this replacement
Telpo TPS900 — 7.4V Li-ion Replacement Battery (325987P)
This 7.4V 2200mAh lithium-ion battery replaces the OEM 325987P cell in the Telpo TPS900 portable point-of-sale terminal. It fits the TPS900 directly and matches the original voltage, capacity, and connector spec. Use it to restore full-shift operation to a terminal that's degraded after heavy daily transaction cycles.
- TPS900 platform fit: The TPS900 uses a single-cell 7.4V Li-ion pack with a BMS that handshakes with the terminal's charge IC on boot. This replacement carries the same cell chemistry and BMS profile, so the terminal completes its power-on sequence without rejecting the pack or throwing a battery fault code.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge sequences on the TPS900 platform, confirmed BMS communication, and verified the charge IC accepted the pack without triggering a fault. Thermal readings stayed within spec across receipt print, card read, and wireless data bursts.
- First deployment tip: After installing this battery, complete one full transaction cycle — card read, receipt print, wireless data — before going live. The TPS900 maps pack capacity during normal operation, and it needs at least one complete power cycle to calibrate the charge indicator correctly.
Receipt printer causing voltage sag during busy transaction periods
The TPS900's thermal printer draws a sharp current spike each time it fires — often 1.5–2A for a fraction of a second. On a degraded original battery, this spike pulls the cell voltage below the BMS cutoff threshold, which triggers a protective shutdown mid-transaction. A fresh cell with low internal resistance handles the spike without the voltage rail collapsing. If the terminal is restarting only during or immediately after printing, the battery is the first thing to swap, not the printer.
Terminal not completing PCI boot sequence after battery replacement
The TPS900 runs a PCI-compliant security check during startup, and part of that sequence verifies battery status via BMS handshake. If the new battery arrives partially discharged, the BMS may report a cell state that causes the terminal to stall at the boot screen. Connect the terminal to the charger first and let it reach above 3.8V per cell before powering on. One full charge-then-boot cycle is usually enough for the terminal to accept the pack and complete its security sequence.