Review on 🔌 UT658 Dual USB Detector: Digital Voltmeter Ammeter for Inspecting USB Chargers and Portable Power Sources - Measures Power Capacity, Voltage, and Current by Mitch Warner

PERFECT for monitoring USB connector output on solar panels. The problem with other counters is that they connect directly to the port. while this one gives you a bit of cable to be able to rotate the gauge and read the display (rather than poking your head under the dash and trying to see the gauge if you can at all). In addition, the reading is ideal for reading in sunlight. Some of these counters have small fonts and use OLED and other technologies that are almost impossible to see in the sun. I'm ordering another one or two today so I can just leave them plugged into my solar panel's USB ports. This is an added benefit if you aren't plugging or unplugging anything into the panel's connectors that can break over time. I'd rather break this $20 device than a $200 solar panel.