Does an iPad or high power Android phone *need* a USB 3.0 extension for full power charging?

I wanted to extend the length of my charging cables. So, I bought these USB 2.0 extension cables from Frys:

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When I got home, I realized that *maybe* USB 2.0 extensions won't fully charge a 2.1 amp iPad (which uses the lightning cable) or a 1.2 amp smartphone (which uses miniUSB connectors).

But I'm not sure...

I'm confused how the USB 2.0 versus USB 3.0 spec has to do with the current that the device (wall charger or computer) will give the iPad or smartphone in the specific case of the USB extension cable.

So, fundamentally, I'm asking whether it matters when charging a late-model iPad Air (lightning cable) or smartphone (Nexus 5) whether I use a USB 2.0 or a USB 3.0 extension cable?

Reply to
Avraham Bernholz
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Avraham Bernholz wrote

I did that with my Logitech keyboard and mouse charging cable.

I used extension cables I got of ebay for peanuts.

Should be fine, the current is signalled by the resistance between the power pins and the data pins with a charging cable and the extension shouldn?t make any difference to that.

It doesn?t, USB 2.0 and 3.0 is an entirely separate issue to how Samsungs and Apples indicate what current they want.

Shouldn?t matter at all, USB 2.0 extensions should be fine as long as there is enough metal in the wire so that you don?t see a lot of voltage drop in the extension cable. And that isnt determined by the USB 2.0 and 3.0 spec anyway, its silent on the gauge of wire used.

Reply to
Rod Speed

The USB 3 standard says nothing about power capacity in excess of the long established 0.9A 5V requirement.

USB 3.1 is the standard which allows for 'more power'.

You only need a USB 3.1 cable if the charger can produce up to 5 Amps at either 12 Volts or 20 Volts (the two new higher power options permitted by the USB 3.1 standard) *and* the thing you want to charge is capable of demanding such higher power (so, only if your device and charger both claim to be up to the USB 3.1 standard).

A USB 3 cable might not suffice in those circumstances.

Plugging a USB 3 or USB 3.1 cable into a basic 1 Amp, 5 Volt, USB charger won't make it any 'quicker' or 'more powerful'. Likewise, a 2A

5V charger will still only provide up to 2A 5V
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Reply to
Whiskers

Whiskers wrote, on Thu, 21 Aug 2014 00:05:19 +0100:

Do I understand this to mean:

  1. If I have a 12V/20V/5A wall charger USB 3.1 wall charger,
  2. And, if my smart device is a USB 3.1 device,
  3. Then (and only then), do I need a USB 3.1 cable
  4. Otherwise, the USB 2.0 extension cable will work just fine.

Is that correct?

Likewise, since I have an iPad with Lightning cable, the USB 2.0 extension cable will work just fine with that Lightning cable.

Is that also correct?

Reply to
Avraham Bernholz

It also depends on voltage supply at outlet - if below 120v then size of wire may reduce voltage below what the device requires or cause very slow charging even when device is off.

Reply to
Zaidy036

Pray tell! what has 120 volts got to do with the charger voltage? Most chargers and wall warts these days are SMPS and regulate from around 90 to 250 volts.

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John G Sydney.
Reply to
John G

Yes.

Normally, but not necessarily always, particularly if its a poor quality USB 2.0 extension cable that has very thin wires that drop a significant voltage when the ipad is getting the maximum current it ever takes.

Reply to
Rod Speed

Rod talks bollocks, so you and he should get along just fine.

*plonk* again, crossposted groups trimmed
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Reply to
Mike Tomlinson

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