I have now tested hundreds of power banks and chargers for breaking, which is without question the most important and largest product category for me.
In this article I would like to show and explain to you how I test power banks and chargers and also which measuring devices I use.
Which measuring devices do I use for tests?
Let’s start with the measuring devices I use. Of course, these vary quite a bit depending on the test, but here is a brief overview:
(Important, everything here is full of affiliate links)
USB Tester / Trigger
Unfortunately, there is no tester who does everything perfectly. The PowerZ models have the best capacity measurement and software for logging data.
The FNIRSI FNB58 is best for reading supported charging protocols and triggering the 100W+ power levels. But due to the USB A port, it is not suitable for measuring capacity via USB C (since a cable always has to be connected between the source and the tester).
The WITRN C4 Pro is something in between PowerZ and FNB58. Works better than the PowerZ KM003C at 140W+, but again has worse software.
The KM001C is used for capacity measurements with up to 100W.
Electronic load
You can find similar electronic loads like the ATORCH DL24 on Amazon, eBay and Aliexpress. Visually these look very similar.
95% of them are no good! The ATORCH DL24, on the other hand, is beyond any doubt for me! This really manages 150/180W, measures itself relatively accurately (even if I don’t use the integrated measuring function for tests but a USB tester) and, above all, discharges very “stable”. Even at 0.1A etc. there is hardly any fluctuation.
The ATORCH DLB-600W is the big brother with “up to 600W”. Nope…. Up to 600W for a few minutes perhaps. Anything over +- 350-400W over a longer period of time will melt the ATORCH DLB-600W. And yes, I’m speaking from experience here!
The load is also not quite as precise, you set 10A and +- 10.3A is drawn, and at low loads it jumps back and forth quite a bit.
Unfortunately, I have not yet found a good and cheap alternative to the ATORCH DLB-600W if I need more than 180W load.
AC measuring devices
The UNI-T is a classic current measuring device. This works quite accurately even at low loads.
The ATORCH AC85, on the other hand, can still measure reasonably accurately even at very low loads (less than 0.4W) and, above all, can log values using the optional software.
Miscellaneous
(Important, everything here is full of affiliate / advertising links)
How does the test work?
Let’s get to the actual test process.
1. Product photos
As you know, I take all of my pictures myself. Accordingly, this is the first thing I do after receiving them.
I have a corresponding photo tent for the pictures with a white background. I go into the garden to take the other pictures.
Photos are always taken first, because power banks with high-gloss surfaces in particular look terrible after handling them once or twice.
2. Initial data
After taking photos, I first measure the products, weigh them, etc.
3. Determine loading logs
Step 3 is checking the loading logs. Does the USB-C port really offer the performance advertised? I usually do this with the FNIRSI FNB58 or the PowerZ KM001.
It is also important to read whether a charger supports PPS.
4. Capacity test for power banks, efficiency measurement for chargers
Power banks:
For power banks, I now start by measuring the capacity. To do this, I fully charge and discharge the power bank. The structure usually looks like this:
Powerbank -> PowerZ KM001C – > USB C Kabel – > Typ-C USB PD Trigger -> ATORCH DL24
If the power bank is empty, it is charged again and usually discharged again at a different voltage/power level.
I log the charging time between cycles, usually with the PowerZ KM001C or PowerZ KM003c. In order to save some electricity, especially in summer, I usually charge my power banks using an off-grid solar system in my office and a 230V converter (and corresponding charger).
Important, I try to avoid a cable between the power bank and the measuring device! These can have a negative impact on the measurement.
Charger
After reading out the charging protocols, I start measuring the efficiency and voltage stability.
As a rule, the following test setup is achieved here:
ATORCH AC85 -> Charger in test -> PowerZ KM001C -> USB C cable -> Type-C USB PD Trigger -> ATORCH DL24
To measure the efficiency, I compare the values on the input side of the ATORCH AC85 with those of the PowerZ KM001C.
For 140W chargers, I usually use the WITRN C4 Pro or PowerZ KM003c in combination with the FNIRSI FNB58, which I use to trigger the 140W level.
Why is this so complicated? Theoretically, the WITRN C4 Pro or PowerZ KM003c can also trigger the 140W level. However, this can be unreliable, especially with the PowerZ KM003c! So I had situations where after a few minutes the connection was lost and the unloading stopped. The FNB58, on the other hand, worked more reliably.
5. Praxis-Tests
Once the tests have been completed, I try out the chargers/power banks on various devices.
Typically this will be the Google Pixel 8 Pro, iPhone 15 Pro Max, MacBook Pro 13 M1, Steam Deck and Dell XPS 13 at the end of 2023.
I do this less to test the charging speed – I can now estimate very well how quickly a device will charge based on the measured values and charging standards – but more to see whether the test device behaves “as expected”.
I would like to have more test devices for practical testing, but I can’t invest thousands of euros in smartphones and notebooks that are here just for testing.
The attempt to persuade manufacturers to take out a long-term loan here has so far failed.
6. Load test on chargers
With chargers, this is the point where I constantly load them with full power for a longer period of time (at least 4 hours).
This is supposed to show temperature problems or something similar. This is more or less the same setup as measuring efficiency.
I do this test at the very end, because if something were to happen to the charger here, I would already have all the other relevant measurements.
7. Writing the text
A not entirely unimportant point is writing the actual test. I usually write this in Google Docs while I create tables the classic way in Excel.
8. Waiting for publication
It can take 5-30 days between creating a test and publishing it, depending on how many other tests I have in preparation.
Shortly before publishing, I copy the text from Google Docs into WordPress and edit/insert the images, links, etc.
Conclusion
I hope you found this post like breaking tests power banks and chargers interesting and informative!