A while ago when I got some Raspberry Pi's, I had a ton of issues with power. I bought a YZXStudio USB power meter/analyzer and a USB load tester, and tested every charger and cable I owned. I found a TON of bad cables which I threw out
Most of the pictures here are actually from 2017, but I never made any posts about them. So if you see I have no USB-C, thats why
This isn't much of a review, but just a post to show you what you can do
Here I'm testing an Anker charger, this thing is great and never drops below 5v at all. You can see the load tester plugged into the analyzer
Here is an example of a good USB cable, also an Anker cable. At 2.5a, its only dropped down to 4.9v
And here is a cheaper, bad cable. The cable feels thick, and looks good, but its clear they cheaped out on the conductors and/or connectors. At the same 2.5a, its only putting out 4.6v. With something like a Raspberry Pi, you will have an issue here. Now pair this with a bad charger, and you are going to have endless issues
Here is an example of a cheap USB charger, with just 1a, the voltage is all the way down to 4.1v! This is rated for 1a, so it should be at least be CLOSE to 4v
You can also use this to test power banks, like the Fenix one I have. Its rated at 1a, and does what it says
If you plug it into a charger, you can also scroll through stats to see all sorts of information. This no-name charger is rated at 3a, and I let it sit like this for 20 minutes, and the charger died...
After I got this, I trashed all of the USB power supplies that could not deliver the rated current, or were no-name branded. I really don't want to risk any kind of fire, for a $10 USB charger..
I also put all the cables in a special bag. They are still okay for Data, but not for power
I actually made a long list of all the cables I had, their length and their performance. I decided on a threshold and rated them. The descriptions are a little weird, since they were just for my own reference. As you can see, the total wattage on some of these cables is way down, to the point where you lose 15% of all power going in, just to the cable. In these tests the cable would feel warm
After doing all these tests, I've only ever bought Anker cables (No, they don't pay me, but I'll take their money if they are reading...)
I also tested the USB Extensions I had, and the cheap Monoprice ones did well!
If you have any requests for tests, let me know!