Brother PT8000 Label Printer Replacement Battery BA-8000 8.4V

Brother PT8000 / P-Touch Series — 8.4V Ni-MH Replacement Battery (BA-8000)

This is the BA-8000 replacement battery for the Brother PT8000 and P-Touch label printer series. It delivers 8.4V at 2200mAh (18.48Wh) through a Ni-MH cell pack. Compatible models include the PT8000, P-Touch 110, P-Touch 200, P-Touch 300, and more than 15 additional P-Touch variants.

• PT8000 and P-Touch platform fit: These models share the same 8.4V battery bay, BA-8000 form factor, and connector pinout. The BMS handshake protocol is consistent across this generation of Brother label printers, so one battery pack covers the entire lineup without modification.
• Bench tested on actual hardware: We cycled this pack on a PT8000 unit through full charge and discharge. The BMS responded correctly at both charge-complete cutoff and low-voltage protection thresholds, with no false trips during the thermal head firing cycles.
• First-use print sequence for Ni-MH packs: After installing, charge the battery to full, then print at least five label sequences before deploying the printer. Ni-MH cells in this pack reach stable internal resistance after initial load cycling — skipping this step can cause the BMS to misread current draw and trip prematurely during the first real job.

Why the PT8000 stalls mid-label after sitting unused for weeks

Ni-MH cells self-discharge at roughly 20–30% per month at room temperature. A PT8000 stored for four to six weeks can drop below the minimum motor drive voltage the paper feed mechanism needs to maintain consistent torque. When the feed motor stalls mid-label, it is not a mechanical fault — it is the battery falling under load. A full charge cycle before use restores the pack to working voltage, typically above 8.0V under load.

Faded or uneven print on a freshly charged battery

The thermal print head in the PT8000 requires a stable voltage supply to maintain consistent head temperature across the full label width. If the battery voltage sags during a print run — common in a degraded or new unconditioned pack — heat distribution across the heating elements becomes uneven, producing faded patches or light bands on the label. This is not a head fault. Run the five-label conditioning sequence described above, then retest. If print quality is still inconsistent after conditioning, check that the battery is reading above 7.8V under active print load.