Products such as USB Charger Doctor are good way to test your USB chargers or cables, as well as checking the power consumption of USB powered development boards. You just plug them into a USB port, and connect the load, and you’ll see the real-time voltage and current shown on an LED display.
Those do the job, but I’ve just been made aware of UM25C USB meter tester that improves a lot on the concept with a dot matrix display capable of showing charts, and Bluetooth connectivity to send the data to Android or Windows devices.
UM25C specifications:
- Display
- 1.44″ color LCD display
- 0-5 brightness setting
- Auto screen off time – 0 to 9 minutes
- Refresh rate – 2Hz
- Measurement Range & Accuracy
- Voltage – 4-24.000V ±0.5‰ + 2digits
- Current – 0-5.0000A ±1‰ + 4 digits
- Capacity – 0-99999mAh
- Energy accumulation – 0-99999mWh
- Load impedance – 0.8Ω-9999.9Ω
- Time range – 0-99h59min59s
- Temperature range – -10 to 100 ±3
- Connectivity – Bluetooth
- USB – 1x USB male port, 1x USB female port, 1x micro USB port, 1x USB 2.0 type C port
- Quick charge recognition mode – QC2.0, QC3.0, APPLE 2.4A/2.1A/ 1A/0.5A, Android DCP for SAMSUNG
- Misc – 4 buttons to navigate menus, Bluetooth switch
- Dimensions – 71.2mmx30.5mmx12.4mm(UM25C)
- Weight – 23.74g
There’s also UM25 version (no “C”) that comes without Bluetooth. An Android app for Android 5.0 or greater, a program for Windows 7 or greater, and related documentation can be downloaded here.
The capabilities of the dongle are well showcased in the video below, which also includes demonstration of Android and Windows apps.
UM25C USB meter tester can be purchased for around $21 on various sites such as DealExtreme, Banggood, Aliexpress, etc… UM25 dongle, without Bluetooth, normally sells for $4 less, or around $17.
Thanks to Ian for the tip.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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Pretty cool, I’ve always complained about the other ones not showing volts and amps at the same time. Using a dot matrix display to have more room for metrics is a good idea. It’s not exactly cheap but it’s acceptable.
https://www.aliexpress.com/item/-/32880908871.html UM34C another new one
What’s the difference between UM34C and UM25C?
Might be an alternative
https://www.banggood.com/POWER-Z-PD3_0-QC4_0-USB-Tester-Voltage-Current-Tester-Ripple-Dual-Type-C-Meter-p-1226355.html
Different price point though. $50+. But maybe it’s warranted since it supports USB PD 3.0 & QC4.0
I noticed many reviewers measuring power consumption using meters of either low resolution or unspecified accuracy giving rise to differing results between reviewers. I searched the market 2 years ago and bought from ‘Franky’ a ‘YZX 1270’, another 5 significant digit USB meter with Bluetooth, with accuracy far surpassing the UM25C, as a result of ‘Franky’ individually calibrating each device off the production line before dispatch. The YZX 1270 is sold at many outlets with better accuracy than the UM25C, but only from Franky (HKong) with enhanced accuracy. Below is a link to review of the standard YZX 1270. I… Read more »
Just noticed this cheaper one which looks as complete (without the communication though), however I’m not sure one can trust its accuracy : https://www.banggood.com/USB-Volt-Voltage-Current-Meter-Voltmeter-Detector-Power-Capacity-Charger-Tester-p-1137098.html
These limited feature one some might find to expensive
https://www.aliexpress.com/item/Hight-Quality-Red-Blue-Dual-USB-Current-Voltage-Charging-Detector-Tester-Battery-Voltmeter-Ammeter-Charger-Doctor/32802268967.html?
And
https://www.aliexpress.com/item/Digital-Dispay-3V-7-5V-USB-Tester-Current-Voltage-Charger-Capacity-Doctor-quick-charge-power-bank/32851100319.html?
And A or B here
https://www.aliexpress.com/item/8-in1-QC2-0-3-0-4-30v-Electical-power-USB-capacity-voltage-tester-current-meter/32812273461.html?
So I just received mine, and I already like it. I do not regret it compared to the apparently cheaper ones. The display is large, very contrasted and quite readable. You have a large number of measures at once, it’s pretty cool. I didn’t read the manual but found my way through the interface via the 4 buttons, it’s more intuitive to use than a browser these days. Thanks Jean-Luc for this review 🙂
I plan measurements that will last for several days. Is this possible with the Android App? If not i should not buy the UM34C because this one only supports the Android App not the Windows Software. Or is it even impossible with the Windows Software? Did anyone tried this? On every Screenshot it seems that the data collecting and export is limited to a few minutes. 🙁