iPads will charge on any USB port...

Discussion in 'NZ Computing' started by Dave Doe, Apr 6, 2010.

  1. Dave Doe

    Dave Doe Guest

    Anyone taking possession of a shiny new iPad this weekend may have
    noticed an odd message when connecting their gadget to some computers or
    USB chargers: the words Not charging in the iPad?s menu bar. We
    experienced the same issue during our initial testing, leading us to
    wonder if there was something wrong with our test unit
    As we reported on Friday, the issue is simply that the iPad has heftier
    charging requirements than iPods and iPhones, and some USB
    ports?especially those on older computers and most USB hubs?don?t
    provide enough power to charge the iPad during use. That doesn?t mean
    lower-power USB ports can?t charge the iPad at all; instead, whether
    they can charge the iPad?s battery?and how quickly?depends on how the
    iPad is being used.
    ?When connected to lower-power USB ports?those on older Macs, most
    Windows PCs, and most USB hubs (powered or unpowered)?the iPad?s battery
    is not charged while the iPad is awake, but is charged (again, slowly)
    when the iPad is asleep. What?s confusing here is that the message Not
    charging appears in the menu bar when the iPad is awake, which might
    lead you to assume that the offending USB port can never charge your
    iPad. But rest assured, Apple says: once you put the iPad to sleep, the
    battery will indeed charge. (If you could see the screen while the iPad
    was asleep, it might even display the charging icon. It?s the modern-day
    ?Does the refrigerator light stay on when I close the door?? mystery.)
    The USB ports on Apple computers provide 5 V (Volts) and 500 mA
    (Milliamps) to each port, regardless of whether the port is USB 1.1 or
    USB 2.0. This is in compliance with USB specifications. On some newer
    Intel-based Macs, such as the MacBook (13-inch, Late 2007), when a
    device requiring more than 5V and 500mA is connected, the port with that
    device connected to it becomes a high-powered port capable of offering
    up to 1200 mA at 12 V. That port will continue to operate as a high-
    powered port until the device is removed.
    Although we haven?t done enough testing to be sure, it appears that even
    though the iPad?s battery isn?t charged during use when connected to a
    low-power USB port, the iPad at least gets enough juice that it doesn?t
    have to draw from its battery. In other words, your battery level
    doesn?t appear to go down.

    In short, there?s nothing wrong with your iPad; it?s just hungry for
    power. In this respect, the iPad is a lot like many USB hard drives and
    Apple?s external optical drive for the MacBook Air: it needs more juice
    than the typical USB port provides.

    Dave Doe, Apr 6, 2010
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.