Honeywell RP4 Replacement Battery 7.4V 5200mAh 550053-000

Honeywell RP4 / RP4D — 7.4V Li-ion Replacement Battery (550053-000)

This is a 7.4V 5200mAh Li-ion replacement battery for the Honeywell RP4 and RP4D mobile thermal printers. It replaces OEM part number 550053-000. The RP4 series is used in field delivery, retail, and logistics operations where printing happens away from fixed power.

• RP4 and RP4D compatibility: Both models run the same 7.4V battery rail and use an identical connector and BMS handshake protocol. One battery fits both variants — no adapter or firmware difference applies.
• Bench tested on actual hardware: We ran this battery through charge and discharge cycles on the RP4 platform. The BMS communicated correctly with the printer's power management circuit, accepted full charge without error, and drove the thermal head and paper feed motor at consistent voltage throughout the discharge cycle.
• First deployment print sequence: After installing, charge fully and print five test receipts before putting the unit into service. Portable printer paper feed motors require this calibration sequence to confirm the BMS current profile is correctly set for the new cell — skipping it can cause false low-battery warnings on early cycles.

Why the RP4 thermal head produces faint output at certain battery states

The RP4's thermal print head requires a stable voltage supply to hold the correct temperature across the full width of a print line. When battery voltage sags — either from a degraded cell or a partially charged new one — the head cannot sustain consistent heat output. The result is uneven print density: darker on one side, faint or blank on the other. If this happens on a new battery, run a full charge cycle first, then re-test at full charge before assuming a hardware fault.

RP4 disconnecting from Bluetooth or Wi-Fi mid-print job

The RP4's wireless radio draws additional current during active transmission, and this load combines with the thermal head draw during printing. At low or degraded battery voltage, the combined draw causes a momentary voltage sag that trips the BMS or causes the radio module to reset. This shows up as a dropped connection mid-job rather than a clean low-battery warning. Charge the battery to at least 7.2V before starting high-volume print jobs and confirm the charge indicator shows full before deployment.