Review request for HKJ [USB Power Devices]

I use a short thick cable because I want to measure the usb supply, not the cable. This is not perfect, my cable has some losses, they can be seen on multiple output chargers. Single output is measure with my standard cable, when paralleling multiple outputs, I have many short cables in parallel and my measured voltage will be slightly higher at the same current.

When used to charge devices the charge current may depend on the cable, it depends on the device. Some devices are more sensitive to low voltage than other. When testing usb chargers I usual simulate a long cable with a 0.5ohm resistor in series with the 5 volt, this can give a good idea how sensitive the device is.

Chargers without an optocoupler will often increase the voltage slightly when loaded, but my preferred chargers has 5.2V always.

We previously discussed about this, I believe your methodology is pretty allright here. I just wanted to pinpoint it would be a nice idea to add a comment in this regard whenever convenient in your final words in the reviews. I personally would not buy something like the Energizer High Tech Mains charger 336:

At 1A load, its already is at ≈4.9V, so there's very very little voltage left to be dropped by cable and connector resistances. Besides, even the “premium” commercial cables suck, in general terms, with regards to their lenght/gauge relationship, which means the voltage drop will have a noticeable impact at high current levels. And if you factor in some people treat their connectors like crap, it's easy to understand why they can't stop complaining about slow charging speed.

Needless to say, I build my own cables.

Cheers ^:)

Hi Henrik

Have you tested the Amazon basic 2.4amp usb charger, they seem to be a reasonable price, You should be able to get an EURO plug version from your local Amazon.

https://www.amazon.co.uk/dp/B01FI2P0WW/ref=twister_B01N1UZ3JO?_encoding=UTF8&psc=1

Thanks

John.

Amazon do not have a Danish department, I either use German or English Amazon, with mains equipment usual Germen because I then get the correct plug.
Anyway I have ordered one, but it will be some time before I get around to test it, I have a fairly long queue of usb chargers.

Hi Henrik, what do you think of this, only $3.65 delivered. (sorry about the bold it will not turn off)

1.2v 12v 18650 Li-ion Lithium Battery Capacity Tester + Resistance Lead-acid Battery Capacity Meter Discharge Tester

https://www.aliexpress.com/item/-/32681742031.html?uttaskid=37002&utcontentid=976&utalgorithmid=2&tracelog=rowan&rowan_id1=eclc_en_7_1_en_US_2017-04-06&rowan_msg_id=johnUTT_37002_$a4ea5d470c6b441eb3dde94ac2d435e1&ck=in_edm_other

John.

The previous link looks much better if “junk free”: https://www.aliexpress.com/item/-/32681742031.html

The bold attribute goes off by selecting all off the involved stuff (or more) and applying/switching it a couple of times, at most (shortcut: CTRL + B).

Cheers

I prefer the ones with constant current discharge. For this one you need to get a couple of power resistors and will not have a constant current discharge.

Something like this is much better: Test/review of Electronic load 60W
The heatsink with a fan do not get as hot as a power resistor and can work at many different currents.

Not a USB power device, but this looks interesting

https://www.aliexpress.com/item/PR10-C-EU16A-home-power-metering-socket-home-energy-meter-power-recorder-electricity-meters-16-currency/32695358611.html

I’ve been using Technoline power meters until now and they have been independently verified as accurate, but this has more features.

I have been using this for a month now and according to my cheap Fluke it seems to be accurate. I like the ZKE software too which is the same as with the USB meters.

http://www.ebay.com/itm/252205821159

Looks interesting and fairly cheap. I always wonder why they only publish the maximum current, in many cases the minimum current where it still has some precision left, is more interesting (You need that for chargers, led lamps and other electronic stuff).
I have ordered one, maybe I get time to review it.

I have that one lying around, but I have not had time to review it yet.

I do never get time to review all the stuff I get/buy, my main priorities are batteries and chargers, everything else is done in between.

It says 0.005-16A in the specs for current range, but that translates to 1.15 watts at 230 volts. But then it also says minimum power 0.1 watts. So what to believe.

I did not check far enough down on the webpage first time around.
It says the resolution is 0.001A, the interesting thing to know is how much current do it need to be fairly precise in PF (Power factor), with AC power measurement that is an very important value.
My most sensitive power meter has a full scale value of 0.001A with a resolution of 0.0000001A (I seldom need that sensitive measurements).

hello HKJ, could you please take a deep look into this powerbank, because there are many report that it fries the charging IC in phone

I will do a check of it, but probably it will test fine. This problem is probably something that just happens once in a while and it is unlikely that it will show up during my test. If it happens I will, of course, have a record of it.

Got the Zhurui meter today.

Quick low current application comparison against UNI-T UT210E clamp meter using a USB power supply (Anker 5 port) and a USB load as load:
Zhurui / UNI-T
0.011 A / 0.009-0.010 A (Anker standby, no load)
0.067 A / 0.062 A (1 A usb load)
0.110 A / 0.103 A (2 A usb load)
0.150 A / 0.142 A (3 A usb load)

Of course the clamp isn’t probably super accurate at those low currents (3% + 10 digits)

That looks very interesting. I bought a mains meter a couple of months ago, but this one's much nicer.

I'm awaiting your experiences with it before ordering one for me :)

Very interested in finding out from HKJ’s review how accurate the power factor is on low currents, since the power measurement doesn’t really matter if that’s out of whack.

The meter is probably not very accurate at low currents. I checked HKJ’s Anker review and he measures the efficiency at 0.25 A to be about 79 . With the meter I got 72 (1.32 W out, 1.82 W in). But for example at 2 amps the results do match.

edit: I take that back, it actually seems very good after I tried a more accurate load (YZXStudio ZL1100) and got 1.2725 W out, 1.60 W in = 79.5 % efficiency).

Also good accuracy at lower load (0.1 A / 0.51 W on the USB load), 71 % efficiency (0.51 W out, 0.72 W in) matches HKJ’s graph. As does at 0.05 A (62 %).

http://www.ebay.com/itm/Key-High-Quality-2-Port-USB-Car-Charger-Rapid-Charging-2-4-Amp-Per-Port-/122082219628

dirt cheap on massive discount. One has to wonder …

I’ve purchased one of these and have been very happy with it. Might be worth a full test.

http://www.ebay.com/itm/262761776634?var=561726596040

Dirt cheap when you live in the US, but shipping to EU is $18