Can I use the iPod Firewire cable with iPhone?

Discussion in 'iPhone Tips, Help and Troubleshooting' started by msharp, Aug 7, 2007.

  1. msharp macrumors regular


    Jul 10, 2004
    The connectors are identical, so I was wondering...

    I would like to use the ipod cable because it's firewire, much faster than usb, and I've got no more usb ports on my laptop.

    Thanks everyone
  2. toneloco2881 macrumors 6502

    Jan 23, 2005

    It may work for charging, but not for anything else.
  3. msharp thread starter macrumors regular


    Jul 10, 2004
    great. thanks for answering ;)
  4. The General macrumors 601

    Jul 7, 2006
    Don't use it! An Apple Product Specialist said the Firewire and USB cables put out different voltages.

    It could fry your iPhone.
  5. DotComCTO macrumors 6502

    Aug 17, 2006
    I accidentally used the FireWire cable with my didn't fry my phone. It charged it just fine. It did not work for sync though.


    ...from my iphone
  6. ZBoater macrumors G3


    Jul 2, 2007
    Sunny Florida
    Well, on mine it blacked out the iPhone and I had to reset. The firewire chargers put out 12V. The USB chargers put out 5V.

    I am NOT an electrical engineer, but in my planet, 12V > 5V = BAD.

    Call me silly. :D
  7. Joshua8o8 macrumors 6502

    Jul 2, 2007
    Honolulu, Hawai'i
    thats good to know because i was going to use the ipod cable to charge my iphone and the iphones cable to sync with my macbook. My outlet is kind of hard to get to so it would be nice to have two cables. O well i wont do that anymore.
  8. dojunmarn macrumors newbie

    Dec 1, 2006
    Electrical charge

    I believe like any electrical system the load would draw only what it requires. So if the iPhone needs only 5volts and the AC adaptor can supply 12, the phone will only draw the 5 required. The AC adaptor does not PUSH the extra 7 volts down the phone's throat. But you should nonetheless ask Apple directly.
  9. mkrishnan Moderator emeritus


    Jan 9, 2004
    Grand Rapids, MI, USA
    Mmmm... I don't think so. Almost all electronics, AFAIK, are current regulated, meaning they output a fixed voltage and vary the current in order to adjust the power output. This is why, when you take a stack of USB chargers for phones, headsets, etc, you can interchange them freely as long as the minimum power draw needs are met. This is also why you can swap between the bigger and smaller notebook power supplies on the smaller machine. However, in all these cases, the voltage is fixed. The current varies to change power delivery.

    The voltage normally does not vary for most electrical devices, generally. An exception however is that many kinds of batteries output slightly different voltages depending on how charged they are. That's why you may have a voltmeter for your battery in your car. But you do "push" the potential difference of 12V onto the device when it is expecting 5V. Just like your car can deal with variability in the design 12V it's supposed to get, or whatever, it looks like the iPhone isn't pitching a fit about it.
  10. Bunsen macrumors member

    May 1, 2007
    Orlando FL
    I meant to reply to this a couple of weeks ago when it showed up...

    The pinout specs for the standard 30 pin iPod dock connector provide for both 5 volts from USB and 12 volts from firewire on different pins. All iPods before the 5th generation "Video" iPods that had dock connectors could use either USB or Firewire for charging and syncing. They just had voltage regulators on the appropriate pins so either would work. On the 5th gen iPods and the iPhone, they didn't have enough room for the firewire controller chip, so firewire sync doesn't work, but they left in the 12 volt voltage regulator to at least stay compatible with most auto chargers.
    When Apple developed the dock connector, they developed a standard. All devices adhere to the connections of each pin, even if they don't support all the features. They knew most people would plug any old iPod into any dock because it fits, and thus they had to make sure nothing would get damaged.
    It is also an evolving standard, as there are 3 pins currently not used for anything.
    Here's the pinout for those that are interested:
  11. AirmanPika macrumors 6502


    Jun 19, 2007
    Vandenberg AFB, CA
    Been charging my iphone for weeks with the firewire charger with zero issues. Anyone who says it will fry your phone is full of crap. Apple intentionally designed the phone to support either since some accys likely use the firewire charging pins.
  12. mkrishnan Moderator emeritus


    Jan 9, 2004
    Grand Rapids, MI, USA
    Ahhh, that is quite illuminating. That makes sense. Thank you! :)
  13. gceo macrumors 6502a


    Jul 13, 2007
    San Diego, CA
    Me too. I've been charging on a FW cable since launch without any problems. I also use a FW charger in the car left over from an iPod.
  14. stephenstudios macrumors newbie

    Oct 8, 2007
    It's funny you say that, considering my iPhone actually got fried because of the firewire charger.
  15. karlwig macrumors 6502

    Mar 7, 2008
    I believe the current USB (USB 2.0) is faster than firewire, but look it up. Anyway your question has already been answered.
  16. risto27 macrumors newbie

    Nov 25, 2008
    Mine got fried too. Just connected it one time and it was enough to completely **** up my Iphone. I wouldn't suggest using Firewire cable with the Iphone.
  17. dukebound85 macrumors P6


    Jul 17, 2005
    5045 feet above sea level
    usb 2.0 is slower than firewire fyi

    edit: way to revive old thread
  18. sergiuria macrumors 6502a


    Oct 21, 2008
    Near a bunch of T-Rex
    I charged my Iphone for over a month because I lost my USB cable, and was to lazy to buy a new one :) and NOTHING happened to my phone
  19. jaxonkohne macrumors member

    Jun 18, 2008
    Thunder Bay, Ontario, Canada
    I know it isn't an iPhone but i was charging my iPod touch just last night with a FW cable and i woke up because my arm had touched the ipod and it was incredibly hot, like hot to the touch and near the charger it was even more hot. Being in a late night daze I didn't think to unplug my ipod because of the potential dangers and left it on... this morning my ipod wont turn on, won't respond to charging, being pluged into a computer, or being reset. I have started saying goodbye because i think that it may be toast... i would discourage anyone from using the FW charger. It may be working for you now, it did for me for months and then bam! So say that i'm full of crap if you want but hey im just letting you know what happened to me.
  20. michael.lauden macrumors 68020


    Dec 25, 2008
    12volt is greater than 5volt equals bad?

    you are silly!
  21. trainguy77 macrumors 68040

    Nov 13, 2003
    I think the problem that people may have with firewire chargers is probably related to the fact that its charging at 12v so more heat would be produced. Heat if not dissipated can cause problems.
  22. mkrishnan Moderator emeritus


    Jan 9, 2004
    Grand Rapids, MI, USA
    Just to point out the obvious for those who aren't reading the dates on this thread....

    This thread is from 2007, and it was therefore originally only about the original EDGE iPhone.

    The charging bus on the iPhone did change between the original iPhone and the 3G. The 3G and other products (touch, nano, etc) from that era onward, AFAIK, do not support 12V charging, either via 12VDC in a car (requiring special adapters with stepdown transformers) or via Firewire. The original iPhone does support those things.
  23. mesharp1 macrumors newbie


    Sep 1, 2009
    the moon
    iPod's, iPhone', iPAD's 1&2 Power Requirements

    Ohms Law P = E x I

    USB 2.0 Speed - Power 500 mA @.5 V / Speed 480 Mbp/s data rate
    IEEE 1394 - Power Max V. 30v @ 1.5A / Speed 50-400 MB/s)

    Now based on the power comsumpuation you can tell that most Apple products can use 1 x USB port of 500mA or .1 Amp to charge the product normally i.e., ipod, iphone, etc.

    However if we are talking about a iPad 2 that needs 2100mA to charge. You will need to use 4 USB ports to power the device since 1 port alone will only let you charge it at the 1/4 (500mA) of power lust you are suck with the wall plug to charge it.

    Futhuremore if using a 1394 firewire adapter then you could use it and charge at 3/4 or more charging saving on charging time.

    iPad2 @ 2100mA

    Cable... You might be not able to sync but you can use firewire port to charge it off your laptop / desktop if needed.

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