USB cable quality / resistance measurement?

Qualcomm QuickCharge protocols require nothing special in the cables, it's all about negotiation. Thence, it's likely that power negotiation failed on the APC M5 cable and it reverted to some other mode. This can happen if the cable has some sort of damage in the data lines; it can be a slight, intermittent failure. I'd test such cable with actual data transmission (like copying some files from computer to phone/tablet and/or vice versa).

fixed it, aged batteries actually lose capacity, thus the only reason for them not being charged “faster” is because of an unusually long and slow constant voltage phase. If you do not allow your device to reach that charging phase (like I do), it actually charges “faster”. This is not really true, of course, as it is due to the lesser battery capacity.

Yep I figured that might be the case also :slight_smile:

My nephew just asked me to grab another BW-MF8 cable for a friend of him. They seem discontinued, and now they're selling a downgraded and more expensive BW-MF10 version. You just lost another customer here Banggood Bangbad.

Cheers :-)

Originally posted on Tue, 07/17/2018 - 13:43. Edited to add joke.

I like your spreadsheet :slight_smile:
There seems to be a few typo’s for the Anker cables. Their site, for some weird reason, only lists AWG for the basic PowerLine
30cm - 24AWG
90cm - 20 AWG
120cm - 20 AWG

is what I got from their site.

Are these cables any good??

https://gopowerbear.com/products/micro-usb-cable
.

I think that question can’t be answered without knowing the AWG of the power wire.
The construction can be super strong but if the wires are thin then the losses will be bad.

OK…… thanks ZoomieFan.

[quote=ZoomieFan]

Thanks, I got these numbers from a little round of googling, so I'm stickin' to them :)

If you want the best of the best micro-USB cable, here it is:

If you want the best of the best USB-C cables, here it is:
https://www.aliexpress.com/item/Ugreen-5A-USB-Type-C-Cable-for-Huawei-P20-P20-Pro-USB-3-1-Fast-Charging/32844394210.html?spm=2114.search0104.3.56.60c334b5DUL8VD&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10151_10065_10344_10130_10068_10547_10342_10325_10546_10343_10340_10548_10341_10696_10084_10083_10618_10139_10307_10059_100031_10103_10624_10623_10622_10621_10620,searchweb201603_13,ppcSwitch_2&algo_expid=f1e8772f-d626-46a0-8834-30774854cf75-6&algo_pvid=f1e8772f-d626-46a0-8834-30774854cf75&transAbTest=ae803_1&priceBeautifyAB=0

Both are 18AWG USB cables. So, top of the top quality :+1: :beer:

Thanks BSM… good info. :+1:

Simply having large gauge doesn’t make a cable good.

The flexibility and durability of the insulation, the quality of shielding, the reinforcing cables inside, the joining between cable and connector, and many other things also matter.

Having had a Dash Charge cable which uses 18AWG wires, and is a great quality cable, and the fact that UGreen cables are great in general, I would have no problem that it is a high quality cable.

Ugreen is definitely one of the better brands, but I’m just saying that in general it is a bad idea to only consider wire gauge.

+1

You are right.

As you said, there are many factors in making a good USB cable.

The other problem with using thicker wire gauge is that flexibility is also affected. And the cable is made even heavier and thicker.

measure the cable resistance, you can use out UM series (um24, um25, um34) to measure the cable resistance
this video show how to measure

Thanks! The more advanced meters now do this automatically. You plug them in directly to the supply, then with the cable in between just like you say, and it calculates the difference. Only thing is most meters only have male USB A in or micro USB, so you can only test micro USB cables. Unless you have this:

Converts micro USB, USB C, Apple Lightning and even direct + and - into female USB which you can then plug your meter into.

I had already bought the Qoopow Qualmeter before I found that though. Yes it’s overpriced, and doesn’t give you direct results.

I bought that interface converter board too, but haven’t used much. It’s handy for converting various interfaces. But for measuring resistances, then I won’t exactly recommend as the board will also add some amount of resistance (so it will affect cable resistance measurements by adding some amount of resistance).

Hmm I wonder if you can calibrate it with a known cable. At least you can use it to compare cables even if you can’t get an absolute value.

It is possible to directly connect the converter board to any given meter by soldering the power leads with short thick wires, plus the data leads. Frankensteining but useful job, of course.

Cheers ^:)

But there are 2 currents - with and without the cable. Which current should I use?