USB Power Supply/charger Test and tear down

Wow, awesome comparison, thank you very much!

I think I'll have to replace one or two USB power supplys I currently use. Those teardown pictures are very helpful and really show the weak links.

Do you have a plan on testing some 12V USB power supplys used in cars? :)

Great and informative test, Thank you HKJ

Not at this time.

This is awesome, thank you!

I’ve always been wondering about that ioncell ps, but I’ve been so sceptical to chinese knock-off supplies, that I’ve just let it be until now - ordered!

Very useful review - thanks for taking the time. Good to know that Intl Outdoor have a readily available safe model I can get should I need a replacement.

Thanks again HKJ. The amount off effort put into this is amazing. Cheers.

As others have said, thanks for all the time/effort to bring this kind of information to us. It’s much appreciated.

Great tests, I guess I'm retiring my green one that looks like yours.

Another test here

That test does include many brand name chargers and very few cheap charger. Notice that the KMS is not the same 4 port ps as I have tested, this is very obvious if looking at his tear down.

Thanks for this big job that you do for us… It is amazing that the most best looking PS are the worts…

In the noise plots for chargers 1, 6, 12, and 13 you clearly see what are commonly called “hanging bridges”. These are highly indicative of the waveform sampling frequency being less than twice the noise frequency (under-sampling). This causes aliasing and distortion of the waveform. The noise level of those devices is probably quite a bit higher than what is indicated.

That might be the case, but I doubt the result would be that much different if I sampled at a higher frequency. I sampled at about 100kHz, i.e. each point on the curve is about 120 samples.

The expression "hanging bridges" is not common around here, I have never heard it before. I tried using google, but did not have much success (There is a surprising number of pages about Brookling bridge and oscilloscopes ).

Awesome teardowns and reviews. Always wondered what had to give in those tiny little cube chargers, now I know!

Hesitant to use my Samsung cube charger now, assuming similar isolation and noise issues.

Makes me wonder how the built-in USB charging ports on my surge protector fare, hoping they are better than these little chargers

Do not worry about the Samsung charges, check the link nekdo12 posted, there is a test of two Samsung chargers and works fine.

Hopefully they are.

i dont know what these ps are good for, are they employed for powering Apple ipads during a work day or for charging Apple liion cells in iphones during the night? never mind.

the 4 most expensive ps were the 4 best? i see :)

goobay .. i think it's German stuff (goobay.de).

Thanks for the superb review!!

The #1 in my test? I will recommend that you break it apart and throw it out, with 0.5 mm in isolation distance it is not something to have laying around.

On the one you linked to, try reading the text on the bottom of it, there it says 1A. It is probably just as unsafe and weak.

If you really want a small ps, buy the Apple one, it is safe.

Yet another quality review by HKJ! Been reading your reviews on chargers and batteries! Reviews are always packed with nice charts and high quality pictures!

Thanks HKJ!

Very interesting and useful, thanks a lot for the effort

I just received 1 of the 1.5a chargers today…and it is 1A. Thanks for the testing, great info!