USB Wall Charger Performance?

That iClever is I think not a certified Qualcomm 3.0 charger but has only exaggerated wattage figures.

I don’t see any official Qualcomm 3.0 logo printed anywhere in its body.

This one has:

It does have the QC logo:

But my question isn’t really about QC3.0. This Samsung tablet doesn’t support QC3.0 or even QC2.0. It’s an older Galaxy Tab S2. I am just questioning this charger’s capability when it comes to regular low speed charging - below 2A current.

Using the QC3.0 port made no difference.

In my experience, the actual charging current is controlled by the device, add to that the quality of the charging cable’s capability to handle higher currents.

Qualcomm’s 3A capability merely just tell us that it can deliver up to 3A, but still it up to the device, the condition of the battery, how many percent is the battery’s present charge state, etc. on how much charging rate it can permit.

I totally understand that, and I am not expecting 3A when charging this particular old tablet. I am just wondering why I am seeing differences in voltage and current when using stock charger vs this iClever one.

BTW, I am using the same cable in both cases.

My Samsung tablet is very picky about its power source.

It charges much faster with its original adapter than it does with my Anker one, despite the Anker one being an excellent charger that works perfectly with everything else I own.

In sharp contrast, my old (1st version) Moto G phone will happily charge from the grottiest 4.4V power source I can find…

Looks like the Iclever is not quite as good—-minimal though—Curious as to the voltage before you plug in the device— I have had similar things happen with low amp output on a couple of my tablets Ravpower block vs stock walwart charger—-but others are always higher with the Ravpower

iClever: 5.03V
Samsung: 5.23V

your incoming house voltage must be lower than when you took the picture—- samsung lower

House voltage is the same.

Voltage actually goes up when I start charging. Right now I am charging it using the Samsung charger, and it is showing 5.43V, at least according to this Drok USB tester - again, that’s why I was asking in my original post if that Drok USB tester can be trusted.

I only have the Xtar USB tester—not sure how accurate they are—I see they’re only $3 right now at Illumination supply

Do you have a link? I can’t seem to find it.

Nevermind, found it.

I think they have Xtars 6 socket USB block for $16 plus good deals on other Xtar products

I think I’m going to order an Anker USB wall charger for comparison.

I have another older AmazonBasics charger, and that one charges with a higher current, just like the OEM Samsung one.

FYI, this is with an Anker charger I just got today… seems closer to the OEM charger in terms of current delivery…

I got several USB wall chargers and tested them with the ZKE Tech EBD-USB+ meter/load tester.

Various chargers seem to behave differently (voltage with respect to current loading).

1) For instance, the Samsung ETA-U90JWS (from Galaxy Tab 7) charger behaves: voltage increases as load increases (0.40v delta).

(this charger doesn’t work well with the XTAR VC4 since it starts at a low voltage (and the VC4 will think it doesn’t have high enough voltage, resulting in slower charge rate; however once the load gets higher, the voltage gets higher, so you could reset the VC4 and it will now work better — that’s my experience while testing this charger for use with the VC4)

2) Then there’s another Samsung EP-TA10JWE (this charger comes with Galaxy S5/Note III), this one tries to maintain fairly stable 5.3v (0.15v delta), and is what I recommend using with the XTAR VC4 (it performs well in my experience — the VC4 can maintain a high charge rate since the voltage remains high)

3) The Samsung EP-TA20JWE (I think this came with Galaxy S6) charger behaves differently: voltage decreases as load increases. (0.15v delta) (again not that good for use with XTAR VC4, as when load increases, the voltage decreases, and charge rate will decrease since the VC4 thinks voltage is going down…)

4) Anker 63-watt 2xQC3.0 PowerSpeed 5-ports charger: the 2xQC3 ports behave differently from the 3xPowerIQ (sorry, mislabeled as “VoltIQ” in the image)

a) the QC3 ports start at a relatively low voltage — almost exactly 5.0v, but tries to remain quite stable at load (0.10v delta).

(due to lower voltage, the XTAR VC4 may think it’s not powerful enough and will charge at a slower charge rate)

b) the PowerIQ ports have a higher voltage and behave a bit differently under load, and is also quite stable (0.12v delta)
(I forgot how it performed with the VC4 charger)
(part of the reason I was testing these chargers at different loads, is because the XTAR VC4 was so picky about the chargers so I had to make some tests to see which it works better)

~

(may be continued)

Thanks d_t_a! Interesting findings. My EP-TA12JWE seems to be behaving similarly to the ETA-U90JWS you tested.

5) This is current load sweep for Apple 10watts (or is it 12watts) charger (this is the charger that came with the iPad 3) (voltage very stable ~ 0.06v delta)
[using ZY1276 protocol detection, it indicates this charger only supports the “Apple 2.1A” protocol, not the “Apple 2.4A” protocol]

6) This is for the BlitzWolf BW-S9 QC3.0 (single-port) charger, behavior is: voltage increases as current load increases - fairly stable voltage (0.19v delta)

d_t_a, where did you buy your USB tester from?

AliExpress. There are several stores there selling the ZKE Tech EBD-USB+ meter. Lowest price seems to be around $18-19 (not including shipping, some countries may have a shipping fee).