For anyone looking to safeguard sensitive electronics or keep critical systems online during an outage, the YX-X804 and YX-X50 power-failure modules promise a compact, all-in-one backup solution. In this hands-on review, we break down what each board offers, how to wire and configure them, and what happens when you cut the mains—no technical wizardry required.

At 01:35 Hardware Explained, we walk you through both PCBs, starting with the YX-X804’s three-phase input terminals, integrated Li-ion charging circuit, and seamless switchover relay. You’ll see how the onboard DC-DC converter keeps your load steady at 5 V or 12 V (selectable via jumper), and how the status LEDs and logic-level pins let you monitor charging, battery voltage, and fault conditions. The YX-X50, by contrast, is a slim “hockey-puck” style UPS module with a single 5 V output, optimized for Raspberry Pi, routers, or small IoT gateways—it uses a MOSFET-based ideal-diode for near-instantaneous power switching.

Jump ahead to 08:39 YX-X804 Tested to see these features in action: we apply a 2 A load, then physically disconnect the mains. The module switches to battery in under 8 ms, holding the voltage rock-steady under load. A quick oscilloscope trace confirms minimal dip, and the built-in over-discharge protection shuts the output off cleanly if the battery falls below 3.0 V per cell. We also demonstrate the board’s adjustable low-battery alarm output and show how easy it is to tweak thresholds with the onboard potentiometer.

At 11:40 YX-X50 Tested, we mount the puck-shaped module under a Raspberry Pi running a stress-test script. As soon as the USB-C supply is yanked, power stays up flawlessly while we hammer the CPU and draw over 700 mA. The tiny footprint hides an impressive 95 % efficient converter, and thermal testing shows it stays cool even under sustained load. We also explore its automatic charging behavior—once you restore the USB power, it top-ups the battery without any manual intervention.

Both modules offer straightforward screw-terminal or solder-pad wiring, clear status indicators, and built-in protections that make them ideal for DIY home automation, remote sensors, or small servers. Whether you need high-current multi-voltage backup (YX-X804) or a sleek single-output UPS for a Pi or router (YX-X50), these boards deliver reliable performance for hobbyists and engineers alike.

🎬 Video Chapters

00:00 – Introduction

01:35 – Hardware Explained

08:39 – YX-X804 Tested

11:40 – YX-X50 Tested