Zebra QL220 Replacement Battery 7.4V 3400mAh AT16004-1

Zebra QL220 / QL320 Series — 7.4V Li-ion Replacement Battery (AT16004-1)

This 7.4V, 3400mAh Li-ion battery replaces the original AT16004-1 (also listed as H16004-LI) in the Zebra QL220, QL220+, QL320, and QL320+ mobile thermal printers. These printers are used for on-demand barcode label output in retail, logistics, and healthcare settings where the unit is carried or belt-mounted throughout a shift. Voltage and capacity match the original pack exactly — 7.4V, 3400mAh, 25.16Wh.

• QL220 and QL320 platform fit: All four models in this series run the same 7.4V battery rail with the same connector and BMS handshake, so one pack covers the full QL220/QL320 family. The BMS on each model reads cell voltage and temperature from the pack — the communication protocol is identical across the series.
• Bench tested on actual hardware: We ran this pack through charge cycles on a QL320+ and monitored BMS communication throughout. The protection circuit responded correctly to charge termination and discharge cutoff events — no false trips, no handshake failures with the printer's onboard firmware.
• First-shift print burst tip: The QL-series print head draws a sharp current spike on every label cut. Install this pack fully charged before the shift starts — a cell sitting at 20% when the print head fires its first burst can trigger a low-voltage BMS cutoff that looks like a dead battery, not a charge issue.

Why the QL220 stops mid-label on the first shift with a new pack

The QL220 print head fires a resistive heating element across the full label width on every print pass. That draws a sharp, brief current spike — higher than the printer's standby draw by a significant margin. If the replacement pack ships partially discharged (which is standard for Li-ion transport safety), cell voltage can sag below the BMS cutoff threshold during that spike. The printer shuts off mid-label and shows a low-battery error even though the pack is not empty. A full charge before first use eliminates this — the cell impedance is lowest when the pack is near full, so the voltage sag under print-head load stays within the BMS operating window.

Printer reports "battery error" immediately after installing the new pack

This usually means the BMS in the new pack has not completed its initialisation handshake with the printer's firmware. The QL-series communicates with the battery pack over a data line alongside the power contacts — if those contacts are dirty or not fully seated, the printer cannot read the pack's status registers and flags a fault. Wipe the battery contacts on both the pack and the printer bay with a dry cloth, reseat the pack firmly until the latch clicks, then power the printer on. If the error clears, place the unit on charge until the indicator shows full — a clean contact at 7.4V nominal resolves this in almost every case.