Charging observation (regarding sync cable length)

Discussion in 'iPad' started by Scott-n-Houston, May 24, 2010.

  1. Scott-n-Houston macrumors 6502a

    Apr 27, 2008
    Houston (duh)
    I ordered some 6' sync cables. They seem to work fine for syncing and for charging my iPhones. I have noticed with my iPad, they charge very slowly. Also, if I'm using my iPad they really don't charge at all. My percentage actually went down while plugged in and I was using my iPad.

    When I use the 3' Apple Cables, I don't have any issues. It charges while using and charges faster.

    These scenarios are while on the 10w charger in a wall plug (not a USB).

    Has anyone else noticed this or observed this?

    Why would it be different?
  2. wiretapMD macrumors member

    Jan 7, 2010
  3. iserian macrumors 6502

    Apr 30, 2010
    Palo Alto Apple Store
    I rarely charge during the day --

    Using 6 foot USB extension cables with the apple cable that came with my Pad's -- for overnight charge no problem.
  4. DeuceDeuce macrumors 6502a


    Aug 8, 2007
    San Dimas, CA
    Same here
  5. ozhood macrumors newbie

    May 24, 2010
    Adelaide, South Australia
    The iPad draws a lot more charging current than the iPhone or iPod. The extra cable resistance results in a lower charging voltage being present at the input of the iPad than would be the case for say... an iPhone. In extreme cases the iPad will not charge at all. Just to be clear here, an acceptable iPad charging current is wayy above the stated specs for USB (0.5 Amp)

    This situation can be improved with larger gauge cables which have less resistance. I'm guessing they should hit the stores any day now.

    Make no mistake though, charging an iPad from a USB port is not a sure thing.

    If you are having charging issues, keep the cable as short as possible or try a different cable. Not all USB cables are created equal.
  6. Scott-n-Houston thread starter macrumors 6502a

    Apr 27, 2008
    Houston (duh)
    Good point regarding the USB cables not being equal. These were very cheap ordered online. I bought several because they were so cheap.
    They work great with my iPhones and iPods, but the iPad is another story. :(

    I suspect the internal cabling isn't quite equal to whatever Apple puts inside their products.

    Why in the world doesn't Apple sell the extra long sync cables that you see in their stores. The Geniuses have them, and if you look at their displays, they use them to connect all the display items. I'd pay decent $ for a 6' or longer cable from Apple that I know will work with my iPad and all Apple devices.
  7. Hammie macrumors 65816


    Mar 17, 2009
    Wash, DC Metro
    I've experienced the same issue with the six foot cable I purchased from Amazon.

    No issues with the standard three footers, but very slow with the six footer.

    Another interesting observation is that the six footer I have uses the old 30-pin adapter that you need to squeeze to remove. I have an old three foot version that came with my 2G iPod Nano and if I use it with my iPad to my laptop, I often get a device not compatible error or something like that. I wonder if the older 30-pin cables had a different wiring schematic that is causing the issue.

    Any thoughts?
  8. Scott-n-Houston thread starter macrumors 6502a

    Apr 27, 2008
    Houston (duh)

    Mine does too. Good observation. I doubt any pins have changed position, but maybe it's the resistance in that setup vs. the new ones?

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