SDG #340 FNIRSI HS-02A 100W USB Soldering Iron and FNB48P USB Power Monitor

USB-C powered soldering irons have moved on quickly, and the FNIRSI HS-02A is one of the more ambitious examples, claiming up to 100W when fed from a PD 3.1 supply capable of 28V. This review looks at whether that headline figure translates into useful thermal performance at the tip, or whether it is mostly marketing built on a peak number that only appears for a moment during heat-up.

The HS-02A is examined physically first: build quality, the handle and grip, the display and control scheme, tip compatibility and the way settings such as target temperature, sleep behaviour and standby are navigated. Because a USB iron is only as good as the supply behind it, the FNIRSI FNB48P inline USB power monitor is used as the measurement tool, and it gets its own walkthrough covering the screen modes, protocol triggering, logging and the general usability of its interface. That combination is the interesting part of the video: rather than trusting the box, actual voltage, current and wattage are captured while the iron warms and while it is loaded with joints.

Calibration is covered too, which matters on cartridge style irons where displayed temperature and true tip temperature can diverge noticeably. Testing then shows how quickly the iron recovers on larger thermal masses, the practical limit of a compact USB tip, and where a mains bench station still wins.

For buyers, the takeaway is about matching expectations: a portable iron like this is excellent for field repairs, travel and light bench work, provided you pair it with a genuinely capable PD supply. The FNB48P is also worth considering on its own as a diagnostic tool for anyone chasing USB charging problems.