About this replacement
Intermec PB50 / PB51 / PW50 Series — 14.4V Li-ion Replacement Battery (AB13)
This 14.4V, 3400mAh lithium-ion battery replaces the OEM pack in the Intermec PB50, PB51, PW50, and PW50-18 mobile thermal printers. These are handheld label and receipt printers used in logistics, retail, and field operations where a mains connection is not available. Cross-references AB13, 318-026-001, 318-027-001, 318-026-003, 318-026-004, and 55-0038-000.
- PB50 / PB51 / PW50 platform compatibility: All four models in this series share the same 14.4V battery bay, connector pinout, and BMS handshake protocol — the same cell pack services the entire line without modification.
- Bench tested on actual hardware: We ran this pack through the PB50's BMS initialisation sequence and confirmed the protection circuit responds correctly to the printer's motor-start current draw at the paper feed and thermal head. No false low-voltage cutoffs were triggered during print cycles.
- First-deploy print sequence: After fitting the battery, charge to full, then run five consecutive print jobs before deploying in the field. The PB50's BMS calibrates its current profile against the thermal head and feed motor load during these initial cycles — skipping this step can result in premature low-battery warnings under normal use.
Why the PB50 refuses to print after sitting unused for weeks
Li-ion cells self-discharge during storage. If the PB50 has been sitting idle, the pack voltage can drop below the printer's minimum motor drive threshold — typically around 12V under load — and the BMS locks out output to protect the cells. The printer may power on and show a charge indicator, but the feed motor and thermal head will not fire. Place the battery on charge for a full cycle before attempting a print job; the BMS will release the lockout once cell voltage recovers above the cutoff threshold.
Faded or patchy print output that gets worse toward end of charge
The PB50's thermal print head requires a stable voltage to maintain consistent head temperature across the print line. As battery charge drops, voltage sag under load causes the head to run cooler than the target temperature, producing faded or uneven output — often most visible at the edges of labels. This is not a head fault; it is a voltage delivery problem. If print quality degrades progressively through a shift, check battery state first and recharge before the pack drops below 13V under load.