About this replacement
Zebra P4T / RP4T Series — 7.4V Li-ion Replacement Battery (CT18499-1)
This 7.4V, 6800mAh Li-ion battery replaces the OEM pack in the Zebra P4T, RP4T, and RP4 mobile printers. These portable thermal printers run on-demand label and receipt jobs in logistics, retail, and field operations — far from fixed power. The cell and BMS in this pack match the current draw profile of the print head and paper feed motor in that printer family.
- P4T, RP4T, and RP4 compatibility: All three models share the same 7.4V battery bay, connector pinout, and BMS communication protocol. A single cell design covers the full platform — no adapter or firmware change needed.
- Bench tested on actual hardware: We ran this pack on a P4T unit and cycled through continuous label print jobs. The BMS held steady through thermal head warm-up surges and paper feed motor start draws without triggering a low-voltage cutoff.
- First-deploy print sequence: After installing this battery, charge it fully, then print five test labels before putting the unit into service. The P4T's BMS uses early current draw data from the paper feed motor to calibrate its discharge curve — skipping this step can cause premature low-battery warnings during the first shift.
Bluetooth dropout mid-print job on the P4T and RP4T
The P4T runs its Bluetooth radio and thermal print head from the same 7.4V supply. When battery charge drops below roughly 6.8V under load, the radio draws enough current to cause a momentary voltage sag. The printer's BMS interprets this sag as a fault condition and can suspend the radio to protect the print head. A battery with degraded cells will hit this threshold much earlier in the shift than a fresh pack will.
Faded or uneven print output after swapping the battery
The thermal print head requires a stable voltage supply to maintain consistent head temperature across the full print width. If the replacement battery has a weak cell or a mismatched BMS profile, the head temperature varies line by line, producing faded bands or uneven darkness across the label. Check that the battery is fully charged before diagnosing the head itself. If print quality normalises above 7.2V on a volt meter, the issue is the battery, not the head.