USB Power Meter with Two USB Ports for Charging and Data Sync, Dual Bright LED Display for Concurrent Real-time USB Current and Voltage Monitor for iPhone iPad Galaxy Smartphone

This USB power meter is great. Just plug it into the power source, then plug the device into port 1 of the two ports (port 2 appears to be current limited). In my initial testing, I used several power sources, including a high-capacity battery bank. I also tested a variety of USB cables (not a significant difference between them, but I tend to buy better cables). It was interesting to see the difference in amps between the power sources -- some tend to max the devices capacity (1 amp, or 2 amp for mine) others show lower amps. I was surprised to find one of my small battery banks never put out more than .5 amp. This meter also showed me the current tapering off as the devices get higher than about 80%, until they are full and the meter shows 0.00 amps (demonstrating the false myth that devices can get over-charged/damaged if left on the charger for long periods -- the device internal charging circuitry prevents this).

I have to have one of these for my electronic repair work, in it's most simple functionality you can tell if a charge port is bad (no amperage level aka the blue indicator means no connectivity via the plugged in electronic.. but you must rule out the cable you have attached to it as well).. and in it's more subtle functionality you can tell if an internal battery is possibly failing... (watch the voltage aka the red indicator, note it's starting voltage with no electronic plugged in.. now plug in the electronic and watch the voltage drop/raise.. for example on a good 3v+ volt battery it may drop to 4.99 and then raise back closer to the starting voltage.. if it doesn't drop lower than the 5v+ rating of the USB the battery might not be as strong as intended and should be further inspected upon repair diagnosis procedure.) You can also just use it to test for bad USB ports in devices.. just plug it in and if no LEDs for either display come up it is not transferring power.. check for obstruction in the port, to corrosion on the pins, to possibly just software disabled power delivery as possible causes of this.

I've been wanting one of these for a while, so I did my research, found one that wouldn't break the bank and was simple to use, and couldn't be happier with it!I've developed a bit of an addiction to gadgets. So I've got a pile of charging cables, multi-port USB chargers, power banks, and car chargers galore. And when you're dealing with all that charging, you begin to notice (at the very least) that some cables seem to work faster than others. A little more research, and I learned that some just don't pull the amount of power they claim to, and the only way I'm going to be able to identify that with any certainty is with this little power meter.The packaging leaves a lot to be desired, and oddly enough, the little box it was in was taped all around with what appeared to be clear packing tape. It was like they were worried the box would come open, and it would fall out. Or like it was a repackaged return -- and no, I have no reason to believe this isn't brand spankin' new, but the tape situation was just weird. Anyhow...There are fancier ones out there, but this Soondar power meter does just what I need it to -- measure the power passing through. I'm able to see at a glance which devices can take a higher charge, what's being put out by chargers and power banks, and even which cables aren't up to par with the others. I would absolutely recommend this to anyone concerned about the time it takes to charge their devices. With this meter, it's easy to see which cables and chargers are really doing the job they claim to be able to, as well as what devices simply don't pull a lot of power to begin with, and you can quickly weed out any that aren't working to full capacity. And at this price, it's probably a good little gift for your favorite gadget hoarder, too!

Works ok, but can be flaky. I bought this to monitor how much power my Raspberry Pi was drawing. It seemed to work well, except after a few days, it read zero amps and the Pi wouldn't turn on anymore. Was worried that the Pi had died only to realize that the meter was not passing power through. Then one port was working and the other wasn't. So, sometimes it works, sometimes it doesn't.

When I first saw this device listed on Amazon, it was irresistible. Fortunately, it works great, and its accuracy is reasonably good, probably +/- 5%, which should be adequate to confirm the devices under test.Some 35 years ago when I was in technical school studying electronics, I learned about meters and shunts, and I built a few using surplus milliammeters, and built a few comparator based pseudo digital voltmeters. They all still work, but are very clunky when compared to this very portable device.Now that we have USB hubs which are supposed to deliver higher charge rates, this inline device readily confirms the charge rate actually being delivered to the device. It is easy to verify if that dual rate USB charging hub you purchased can really deliver 1.1 or 2.1 amps to the load.And if it matters, you can multiply the voltmeter reading by the ammeter reading to easily determine watts.This meter is so small that it will easily fit into my travel peripherals kit, and it weighs only 1 ounce.

Simple unit that does the intended job. I really like the large, easy to see LED digits and the fact that the volts and amps are different colors making it very easy to see at a glance which is which.I gave it four stars because the quality control could use some improvement. I ordered two units and on came through with the opening in the case misaligned with the internal connector. A small file quickly fixed this. Hint: to take the case apart, there is a screw hidden under the sticker on the back.

Simple to use, seems to be accurate and is useful for troubleshooting.