Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Can an IPOD be recharged using electrolytes?

  1. Feb 16, 2008 #1
    Hi,

    I'm just wondering if this is true and any explanation why it works would be just grand.
    http://www.youtube.com/watch?v=GfPJeDssBOM
     
  2. jcsd
  3. Feb 18, 2008 #2

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    It looks like a pretty straightforward application to me. Obviously the pin connectors for the USB charger are composed of a different metal than the negative housing. The 'electrolytes' are a salt bridge between the negative side and the positive pins in the USB charger cable. The USB cable acts as a limited use battery (and an expensive one too) which partially charges the battery in the IPOD. I suspect the copper components pretty quickly corrode away and the trick doesn't work for long... neither does the USB cable.
     
  4. Feb 18, 2008 #3

    mrjeffy321

    User Avatar
    Science Advisor

    It is interesting that you should take this video at face value, chemisttree.
    I am far more skeptical of its validity, especially when considering the other videos that same YouTube user puts out which are even more difficult to believe (for example, this one, or this one).

    Although it is not entirely implausible to think that some type of voltaic cell is being constructed using the onion and USB charger, I think a more likely explanation is that the video is faked.

    I do not know what types of metals they use to make USB plugs (perhaps Copper, Gold, Nickel, or steel), but whatever they are they are probably not that far apart in their reduction potentials. The voltage from such a cell would probably not be very high, and in order for it to recharge the battery it would need to be at least 3.7 volts (the voltage of the Li-ion battery the iPod uses).
    Not to mention the very small reaction area over which the redox reaction could occur, the so the current would be very limited and the voltaic cell would supply a very small power.

    How do we know that the iPod in the video is actually operating on the ‘power’ supplied by the onion-cell? For all we know it does have internal battery power and that is what it is using and off-camera someone turned it on when we (the viewers) could not see.
    Perhaps another possibility is that the iPod turns itself on when it detects a closed-circuit in its battery charger (I don’t have an iPod, so I cannot check this).
     
  5. Feb 19, 2008 #4

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It's garbage.

    - Warren
     
  6. Feb 19, 2008 #5

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Whaaaat? You think someone could have faked a YouTube video? Say it ain't so!
     
  7. Feb 21, 2008 #6
    Does look extremely garbage, the only explanation I could think of for this working is making a galvanic cell within the actual USB port maybe?
     
  8. Feb 21, 2008 #7

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes, and that current might be sufficient to cause a signal in the IPOD and cause it to wake up and display the charging icon (as MrJeffy has suggested).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Can an IPOD be recharged using electrolytes?
  1. Rechargable batteries (Replies: 1)

  2. Rechargable batteries (Replies: 5)

Loading...