Is it Possible That a USB Extension Cable Drains Battery Faster?

Discussion in 'iPhone' started by solo118, Oct 3, 2013.

  1. solo118 macrumors 65816

    May 16, 2011
    Long story short, I bought a cheap USB extension cable for my iphone so I can have extra slack when using the phone in bed, etc.

    When I first started using the 5S it had great battery life, nearly 7+ hours of usage which is amazing for the options I had left on. For whatever reason the first few days of having the phone I did not plug in my USB extension cable.

    Just a couple of days ago I went back to using the USB extension cable, my usage is down to about 6 hours (no change in settings, apps or anything like that) I am finding the battery to drain faster when using apps, or safari etc.

    I know 6 hours of usage is still pretty good, but I am just wondering if it has to do with the extension cable, or is it all in my head?
  2. deeddawg macrumors 604

    Jun 14, 2010
    This doesn't make sense.

    If you're plugging the phone in, how is the battery draining instead of charging? :confused:

    Otherwise there's a very simple thing to try. When you did A you had result X. Now when you're doing B you get result Y. The obvious next steps are to try A again and see if the result goes back to X; then try B and see if the result changes yet again.

    Translation: stop using the cable and see if the behavior changes. Then start using it again and see if it changes once more. Keep all other things the same as much as possible.
  3. Interstella5555 macrumors 603


    Jun 30, 2008
    It's possible if tethering or using other battery intensive task that the battery can be drained faster than it's being charged, but doesn't sound like that's the case here. Actually, backing up, if the third party is charging at a lower rate than a first party one I guess it would be possible to do this at lower usage than normal, but you'd still need to be taxing the phone pretty hard.
  4. Gjwilly macrumors 68030

    May 1, 2011
    SF Bay Area
    An extension cable can make the battery charge slower but it can't make it drain faster.
    If you're using it while charging you might be mistaking slow charging for draining but technically there's a difference.
  5. solo118 thread starter macrumors 65816

    May 16, 2011
    I may have been misunderstood, I meant when I take it off the charger (at 100%) I noticed my battery has decreased.

    Last night I removed the extension cable and charged with the supplied Lightning cable. I will post results later today, but so far I am at 91% with 45 minutes of usage so its looking good!
  6. Apple fanboy macrumors Core

    Apple fanboy

    Feb 21, 2012
    Behind the Lens, UK
    How do you work out that you are doing exactly the same tasks each day? For example if i spend longer playing games than playing music on another day I would get different results. For this experiment to work you would have to use a controlled set of tasks, like playing a video on loop all day. Otherwise it is biased by how many times your girlfriend Facetimed you.
  7. AJ007 macrumors newbie


    Apr 16, 2012
    Syracuse, NY
    I've noticed, that different quality extension cables won't work right with the 5s and ipad4 with ios 7. I'm guessing the cheaper ones you poor quality wires and you get more voltage drop. i use a belkin ext cable and a apple cable with a 12w apple brick and it will charge 5s and ipad4 in ios7 perfect. But yes, the longer the cable the less power gets to the device, it's a tiny loss but these devices seem to monitor it very closely.
  8. solo118 thread starter macrumors 65816

    May 16, 2011
    This is what I am thinking. Maybe I am better off investing in a 2m lightning cable from Apple.
  9. deeddawg macrumors 604

    Jun 14, 2010
    I'm confused. If you take it off the charger (it's saying 100%) it suddenly/immediately drops to some lower number?

    Or are you saying you think using the USB extension cable during charging is somehow affecting battery usage later on when you're not connected to the cable?
  10. solo118 thread starter macrumors 65816

    May 16, 2011
    I believe the extension cable is affecting my usage throughout the day (drains quicker than without it)

    I generally have the same usage during the day. Emails come in, I use safari but nothing too intense such as streaming etc.

    The battery is still good, I am happy with 6 hours of usage but the first couple of days (before using the extension cable) I was getting 7 hours.
  11. deeddawg macrumors 604

    Jun 14, 2010
    How do you suppose that's happening? I'm assuming you're not dragging the cable around attached to the phone all day, just attached while the phone's charging overnight.

    Do you think 100% charged isn't really 100% charged?
    Or do you think the phone is somehow remembering that it was attached to the cable?

    I'm trying to understand what exactly you think is happening.
  12. takeshi74 macrumors 601

    Feb 9, 2011
    It's not. An extension cable can affect how quickly your device charges (or charges at all) but a 100% charge is a 100% charge whether it is done with or without an extension cable.

    As stated earlier it's very difficult to ensure that usage is exactly the same from day to day. A difference of an hour is easily within your margin of error. Additionally, other factors such as coverage will impact battery life as well.

    This all sounds like a flawed notion of causality.

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