Welcome to iPadForums.net Guest - Click Here to Register

Usb charging

This is a discussion on Usb charging within the iPad 2 Forum forums, part of the Apple iPad Discussions category; Originally Posted by KJSmitty Originally Posted by DontUnderstandMyIpad Have you connected the USB cable to a pc/laptop? The iPad draws a current of 10A and ...

iPadForums.net is the original Apple iPad Forum! Registered Users do not see these ads. Please Register - It's Free!
+ Reply to Thread
Page 2 of 2 FirstFirst 1 2
Results 11 to 17 of 17

Thread: Usb charging

  1. #11
    iPad Enthusiast
    Member #
    37165
    Liked
    2 times
    Join Date
    Mar 2011
    Location
    Minnesota
    Posts
    374
    Quote Originally Posted by KJSmitty View Post
    Quote Originally Posted by DontUnderstandMyIpad
    Have you connected the USB cable to a pc/laptop?

    The iPad draws a current of 10A and only the iPad wall charger supplies this current. A pc USB supplies a much lower current and will thus only trickle-charge the iPad.
    I hope it's not drawing 10A.... :-). The battery would last only a few seconds if that.

    For the OP,

    USB only puts out around 5 watts and 1amp. That is why the iPad charges much slower connected to a PC/laptop vise the supplied 10 watt 2 amp power block.
    Double check your USB specs... it is my understanding USB 2.0 is limited to 500 milliamps (0.5 amps). USB 3.0 is 900 milliamps (0.9 amps).

  2. Ads


  3. #12
    iPad Enthusiast
    Member #
    37165
    Liked
    2 times
    Join Date
    Mar 2011
    Location
    Minnesota
    Posts
    374
    Quote Originally Posted by KJSmitty View Post
    Quote Originally Posted by DontUnderstandMyIpad
    Have you connected the USB cable to a pc/laptop?

    The iPad draws a current of 10A and only the iPad wall charger supplies this current. A pc USB supplies a much lower current and will thus only trickle-charge the iPad.
    I hope it's not drawing 10A.... :-). The battery would last only a few seconds if that.

    For the OP,

    USB only puts out around 5 watts and 1amp. That is why the iPad charges much slower connected to a PC/laptop vise the supplied 10 watt 2 amp power block.
    Double check your USB specs... it is my understanding USB 2.0 is limited to 500 milliamps (0.5 amps). USB 3.0 is 900 milliamps (0.9 amps).

    Actual current flow varies with the charge level required. If charge is really low, then the demand current wise is higher. As the charge reaches full, the current tapers off so as to not over charge. That is the regulators job. I know too much detail.

  4. #13
    iPad Fan
    Member #
    39405
    Liked
    2 times
    Join Date
    Mar 2011
    Location
    DFW, TX
    Posts
    141
    Quote Originally Posted by madhatter61
    Double check your USB specs... it is my understanding USB 2.0 is limited to 500 milliamps (0.5 amps). USB 3.0 is 900 milliamps (0.9 amps).
    No need to double check my specs. I already knew them as stated. Maybe you would have preferred "up to 1A".

    The only point worth taking away is something that has the capability to charge at 2A will charge the same battery faster than something capped at .5 or even 1A etc.

    Cheers

  5. #14
    iPad Junkie
    Member #
    11919
    Liked
    10 times
    Join Date
    Aug 2010
    Location
    Virginia, USA
    Posts
    732

    Just use the 10 watt charger it came with

    You can buy another if you need it from guess where? your iPod or iPhone or USB port do not put out 10 watts, only the iPad charger does.
    If my Irish Wolfhound doesn't like you neither will I.
    2012 13" MBA, 2011 11" MBA, 2010 15" MBP, 2 iPad3s, 1 iPad Mini, iPhone 4S and iPhone 5. A bunch of iPods and an Apple TV.

  6. #15
    iPad Enthusiast
    Member #
    37165
    Liked
    2 times
    Join Date
    Mar 2011
    Location
    Minnesota
    Posts
    374
    Quote Originally Posted by Nickso View Post
    Some USB ports put out a different amount of current (mA)
    The USB ports on my desktop monitor put out very little power. Most USB hubs have a power supply with them and they put out more power, but I don't know if enough to make the iPad show that it is actually charging. I have a USB hub so I will try it later and let you know.
    If you read up on the specs of USB 2.0 you will find the max current is 500 milliamps ... that's 0.5 amps. USB 3.0 is expecting up to 900 milliamps.

    The Apple charger puts out 1 amp ... at 10 volts that would be 10 watts.
    Or if limited to 5 volts it would take 2 amps to equal 10 watts. Standard USB chargers won't charge your battery.

  7. #16
    iPad Fan
    Member #
    39405
    Liked
    2 times
    Join Date
    Mar 2011
    Location
    DFW, TX
    Posts
    141
    Quote Originally Posted by madhatter61

    If you read up on the specs of USB 2.0 you will find the max current is 500 milliamps ... that's 0.5 amps. USB 3.0 is expecting up to 900 milliamps.

    The Apple charger puts out 1 amp ... at 10 volts that would be 10 watts.
    Or if limited to 5 volts it would take 2 amps to equal 10 watts. Standard USB chargers won't charge your battery.
    Actually,,,,,,,

    1. Both USB and the iPad charger put out /charge at 5 "volts". (+ or - a small percentage)

    2. The iPad charger puts out/can charge at 2.0 "amps". (2.1 to be exact)

    3. Depending on the USB source, IE: your PC, car adapter, other plug-in style adapters etc, it can put out/charge "up to" typically 1.0 "amp" max.

    4. Thus, both charge at 5 volts yet the iPad charger can charge at 10 watts and the other between 2.5 and 5.0 watts. (volts x amps = watts)

    5. BOTH will charge the iPad.... Yet if only charging at 2.5 watts it will take significantly longer. Especially if the iPad is being used while charging. Basically the difference between a quick charge and a trickle charge. Never the less, both will charge unless the amps/watts provided during the charge are exceeded by the demand from the iPad battery etc.
    Last edited by KJSmitty; 04-01-2011 at 12:05 AM.

  8. #17
    iPad Fan!
    Member #
    10373
    Join Date
    Jul 2010
    Posts
    7

    Energizer PowerPack PC007 iPad Adapter

    I am using the PC007 iPad Adapter by Energizer to charge my iPad when using a computer USB port.

    When possible, I always use the outlet adapter that came with the iPad. That adapter is just a neat accessory to have but not a necessity


Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Similar Threads

  1. Replies: 7
    Last Post: 03-21-2011, 02:42 AM
  2. Charging
    By Aldo in forum iPad Help
    Replies: 3
    Last Post: 12-26-2010, 02:42 PM
  3. Charging?
    By HUNTER1 in forum iPad General Discussions
    Replies: 7
    Last Post: 07-26-2010, 10:57 PM
  4. Charging while using
    By Sayishere in forum iPad General Discussions
    Replies: 0
    Last Post: 07-25-2010, 06:31 PM
  5. Charging???
    By HarlyFan in forum iPad Help
    Replies: 7
    Last Post: 07-12-2010, 08:51 AM

Search tags for this page

charging current ipad2
,
how many amps does a usb port put out
,

how many amps does an ipad draw

,
how many amps does ipad2 draw
,

ipad 2 charging current

,
ipad charging current
,
pc007 ipad adapter
,
pc007 ipad usb adapter
Click on a term to search for related topics.