5A/9V LED Display Multi Tester Dual USB Output Current Detector for Phone Charger, Power Bank

I already own several USB power monitors, including the  DROK Dual-USB Detector . This product ( LED Display Multi Tester Dual USB Output Current Detector ) seems to offer the same functions at half the price, so I decided to give it a try.The product was shipped from China and took 3 weeks to arrive. Not a big deal in my case. It came with zero documentation, only a label on the plastic bag that says:KEWEISIModel: KWS-10VAVoltage: 3-9V +/- 1%Current: 0-3A +/- 1%[Accuracy]I compared the accuracy of this USB meter against a professional digital multimeter (Agilent 34401A). The voltage reading is close enough, showing 5.07V instead of 5.035V. But accuracy of current reading is very poor, especially at the lower end. For example, at 0.5 Amp current, the reading of this USB meter shows 0.45 - 0.46A, or 8-10% too low. At higher current such as 1A, the USB meter shows 0.97A, which is just 3% lower.In contrast, the current reading of my DROK USB meter is consistently accurate to the last digit (0.01A), or just 1% error at 1 Amp.[Other Observations]- The two USB ports can be used for both Power and Data, which is good.- The meter itself consumes 13mA with no load connected- Depending on the orientation of the USB port, the LED display could be facing the wrong way. The DROK meter is better in this aspect, since it comes with a short USB cable connector.[Bottom Line]The KEWEISI USB meter is not as accurate as the DROK counterpart. But for most applications, all you need to know is whether your USB port is charging at slow (0.5A), fast (over 1A), or not at all. A precise reading is not really necessary in this case. Therefore I consider this product a good value just for its lower cost.

Well this is a really nice amp meter for testing charging speeds from phone adapters and computer usb ports . It's a handy tool for testing cables because not all cables are fast chargeThis adapter dose support fast quick charge 3.0The only issue I found was as u see in the 3rd pic is that the USB was not properly align in the cut out hole on the tester but for 5 $ that not something to realy complain aboutSo I give it 4 out of 5 stars because if the port not being aliened but u get wait u pay for so I'm really happy with it recommend it..

I have struggled sometimes with charging. Sometimes I plug in my phone and get barely a trickle. Sometimes I get nothing. I can painstakingly test each piece by waiting ten minutes and switching out individual pieces or I can throw away everything and start over. Generally I go for tedium, because I am cheap. Since getting this product I have discovered two faulty USB ports on a power strip, two useless USB to miniUSB charging cables and 1 phone charging cable that wasn't worth having. I absolutely love knowing that my phone will be charged when I plug it in.

I read the current top review by "NLee the engineer" before I bought this, so I did make an educated decision to buy this cheaper-than-DROK tester and prepare to tolerate its inaccuracy and inflexible output position (i.e. "Depending on the orientation of the USB port, the LED display could be facing the wrong way. The DROK meter is better in this aspect, since it comes with a short USB cable connector"). In that sense, I can not complain. The rest of this review is just a FYI.Recently my tester dies, and the reason was presumably that I frequently plug two tablets into it to charge at the same time. My power adapter with "5V 2A" rating was pushed to its limit to output "5.5V 2.5A" and generating lots of heat, so hot that sometimes I would need some warm-up before I can touch it. I figure such over-working would theoretically be bad for my power adapter's life, but I never thought it would be a problem for this USB tester because it was rated at 5A/9V. As it turns out, in a hot afternoon, this USB tester died with some melting plastic smell. At a hindsight, it probably died because the excess heat, not because the voltage and current. Nonetheless, my next USB Tester will be a DROK unit. Its built-in short USB cable connector would be able to reduce the heat reaches the circuit board.Rest in peace.

It does what it is supposed to, what more could you ask for?I used this to check which USB cords were for faster charging (some cords allow faster charging but no data, others allow data but slower charging, and they usually aren't marked as to which is which), which USB ports charged faster (e.g. USB2 vs. USB3), and how fast I could charge from a battery pack.At least one reviewer stated that the accuracy was not as good as is claimed (e.g. reading up to about 10% lower than the actual voltage/current). I cannot confirm the accuracy, but I can say that for *my* purpose, the accuracy was good enough (e.g. if I get readings of 1.5A and .43A, but they are really 1.48 and .49, I still know which cord/port is better). If you need +/- 1%, you need to pay for high end equipment. But for most consumer uses, this should be fine

I recieved the item today, carefully opened the package and plugged it in to my cell phone charger. The charger was my OEM Samsung charger and was working fine, happily charging my Galaxy S7 Edge.I installed the USB tester in line between the charger and the phone. The screen lit up, displaying Volts amd Amps but almost as soon as it turned on it blinked off. While screen was dead, the output still charged my phone.I tried it on two other known to be good chargers but the screen just doesnt work at all.Needless to say I am not happy with this purchase.

I needed a way to measure voltage and amperage from a USB port and this does the job. I have no way of testing the accuracy, but the results it displays seem in line with the rated volts and output of the ports I have tested. I have even found some dead or under performing ports. I think it is accurate. It’s easy to use and read.I recommend it

Great little device, I have not used it to measure anything that will do QuickCharge using higher voltages as I don't own any devices that can charge with QC. All the devices that I have measured during charge appear to be accurate, I have a different USB measuring tool and the results are comparable with each other. Very visible with the bright numbering.This is a great tool to find out if your devices are charging properly, or you have a low quality/faulty cable. Most devices will charge at up to 2.0A with a good cable. I've used this to find the low quality cables that I thought were good and only charged at around 1A.