USB cables for power

[Shade]

I don’t know if anyone else is having the same experience, but my x98 Pro is ~extremely~ picky about which USB cable I use to charge it. Also which chargers, but I have that sorted out already.

I have one cable that is 6ft that gives me full power – enough to run it at full power and charge the battery at the same time – but all the rest of the cables that can do that are 1.5ft shorties.

Does anyone happen to know of a good source of cables for these things? I’d rather not buy a bunch and do the trial and error myself if anyone has leads on what cables have worked for them.

[Samuel Kwok]

The quality of USB cables and length has played a big part in charging speed for mobile phones, it’s no surprise it applies to tablets.

[Anonymous]

Hello, as you may be aware by now, this tablet consumes a lot of power. The Intel Atom CPU can need up to 8W and the screen is big and draws power too. That’s why the charger that comes with the tablet is a 2.5A one, and the USB cable is short and thick.

You need a charger capable of providing at least 2.4A, there are a lot of those. And you need a USB cable capable of carrying that current without much resistance. And here we have to apply what we learned on school about Ohm’s law. The resistance is proportional to the length of the cable and inversely proportional to its thickness.

For a 2 meter (6 ft) cable you need it to be made with thick copper wires. The standard way of measuring that is AWG. The USB cables we have been using to connect and charge cell phones have thin copper wires inside, classified as AWG28.

To carry more current to greater distances you need cables with power wires classified as AWG22, AWG20 or AWG18. I have three 6ft cables that have those specs and they can charge the tablet while I’m using it (a 5% in the time it took me to write this).

 

[Shade]

Thanks, vcespon. The AWG rating for the cables was the detail I didn’t have. I have more than one cable that is thicker but doesn’t pass a full current. Must be a thicker plastic sheath and not thicker copper. Makes sense with this low voltage: I’m sure the voltage drop is significant. An excellent and generous post.

[Author]

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