Sunday, April 7, 2013

How to choose a good USB data and charging cable for your mobile phone

Most of us will have a few USB data and charging cables for our mobile phone, i.e. one at home, one in office, one carrying together with our laptop, etc.

Do you encounter the problem of slow charging, or worst still, unable to charge with the additional USB cable that you bought? Perhaps you can find the solution after reading this.

First of all, although most of the USB cables look alike from their external appearance, they might be different inside the cable, and probably that is the ready why certain USB cable unable to charge your mobile phone, certain can charge but at a very slow rate, certain just work as fine as the original USB cable that come with your phone, and certain even can charge faster than the original cable.

There are 5 wires inside the USB 1 and USB 2 cables, and there are more inside USB 3.0 cable. Since most of the mobile phones nowadays are using USB 2.0 connector, so USB 3.0 is out of our topic here.

The 5 wires are:
  • 2x 28 AWG data lines
  • 2x 20-28 AWG power conductors
  • 1x drain wire
and those 5 wires are connected to the 5 pins in your micro-USB connector.

In fact, there are two kinds of USB cable: fully-rated and sub-channel. The main difference between them is that fully-rated cable can be used for typical peripherals operating at the rate of 480 Mbps (high speed) signalling, while the sub-channel one at the rate of 1.5 Mbps (standard speed) signalling. The construction inside the cable fully-rated and sub-channel cable is different.


As you can see from the diagram above, the fully-rated USB cable is shielded by braid and aluminium foil.

You can probably see some printed codes on the good quality USB cable, including something like this: "28AWG/2C and 24AWG/2C" or "28AWG/1P + 24AWG/2C".

The first code is normally the specification of the data signal pair, which is normally 28AWG. "2C" means 2 conductors, and "1P" or "1Pr" means 1 pair. "2C" and "1P" are basically the same.

The important part is the second code, which is the specification of the power distribution pair. The minimum requirement is 28AWG, and the lower the AWG number the better. This is because lower AWG wire is thinker, and therefore the electrical resistant is lower.



Therefore, charging with a "28AWG/1P + 28AWG/2C" USB cable is normally slower than a "28AWG/1P + 24AWG/2C" cable.

Certain USB cable comes with a ferrite bead at one end, which function is to filter high frequency noise to improve signal transfer.


As a conclusion, when you buy additional USB cable to charge your mobile phone, you should look for:
  • USB 2.0 support
  • High speed 480 Mbps data transfer rate
  • The packaging mentions it is a "charging" cable and not only a "data" cable
  • Power conductors of 24AWG/2C or better (for faster charging speed)
  • (optionally) the ferrite bead
Remember not to only look for the information on the packaging of the cable. Sometimes you will find the specification printed on the cable is different from that mentioned on the packaging.


22 comments:

  1. your blog is fantastic
    lets know something about : Reliable information provided by Alarm System Report is very useful for choosing top alarm systems.

    ReplyDelete
  2. This is fantasticcccccccccccccccccccccccccccccccccc!!!!!!!
    Grrreaattt!

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  3. Thank you! I have recently purchased several new cords and NONE of them transfer the power quick enough to charge my phone. -thanks to you, I finally know why.
    Blessed Be!

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  4. Hello!
    Thank you very much for informative post on USB cables!
    This is just what I was looking for.
    Could you point me to your resource please? Where did you obtain that table with comparison of full-rated and sub-channel cables and the diagrams?
    Thanks again, keep up the good work!

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  5. @giomjava

    From the manufacturer's specification documentation.

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  6. Great info. Where can I go to purchase some good quality cables?

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  7. @John Picard

    My choice of brand is Pisen. It works well for me.

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  8. Many thanks for these explanations, some usb cables didn't properly charge my phone, now I know why!

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  9. Thx ! Really learnt a lot from you since I joined you blog.

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  10. Thanks. Maybe that explains why I go through charging USB cables every 6 months.

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  11. Thanks. Maybe that explains why I go through charging USB cables every 6 months.

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  12. What if its only USB cale with 1000 mbps speed rate

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  13. Thank you very much.. Very informative..

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  14. Fantastic post with excellent images. Recently I have ordered a Phone Data Cable for my phone from "mobansp" store. Now I am thinking that your post will be more attentive for me as, all these information about the usage and feathers of data cable will definitely help me to use data charging cable in a proper way. Thank you so much. Very informative post

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  15. Hi Voyager 8, your blog is really informative, i just have some questions as follows, 1. what is the function of drain wire and braid and foil shield. 2. What AWG no. of data line can support 480 mbps transfer rate. 3. Is the data line speed matters when wireless data transfer are now available such as blutooth and other apps. ? thanks. from CELLZONE

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  16. @Charles Tomas

    The drain wire is for grounding purpose.

    The aluminium foil is also for grounding purpose.

    The metal braid is required to enclose all the wires in the cable.

    USB 2.0 24/28AWG cable can support 480 Mbps data transfer rate.

    Bluetooth speed is much slower. Current wireless charging technology speed is also much slower.


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  17. Very informative post. Thanks for sharing.

    I have an issue that maybe you have encountered. I used a USB type B connector (28AWG/1P+26AWG/2C) to connect a sensor and got nothing from Device Manger. I tried another 28AWG/1P+26AWG/2C and also got nothing. I then tried my cell phone and also got nothing, so I isolated it to the cable being the issue.

    I used the exact same port but this time used a 28AWG/1P+28AWG/2C wire and tried the sensor and Device Manager detected it. To confirm I unplugged the sensor and plugged my phone into it and it also detected it and started charging it.

    My assumption would be that a 28AWG/1P+26AWG/2C cable would work "better" power wise than a 28AWG/1P+28AWG/2C cable.

    The 28AWG/1P+26AWG/2C wires weren't kinked or used. Outside of a bad batch, any ideas why the two 28AWG/1P+26AWG/2C cables would not work with the sensor or the cell phone?

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