1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Why removing and replacing remote battery makes it work?

  1. Nov 18, 2016 #1
    Sometimes when my TV remote doesn't work, I've tried removing the battery and replacing it (the same battery), and it works again. How does this work?
     
  2. jcsd
  3. Nov 18, 2016 #2

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Dirty contacts.
     
  4. Nov 18, 2016 #3

    anorlunda

    User Avatar
    Science Advisor
    Gold Member

    It is like CTRL-ALT-DEL. All software controlled devices seem to need that every so often. :wink:
     
  5. Nov 18, 2016 #4

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    If the battery is almost flat the heat from your hand can sometimes be enough to kick start the battery chemistry raising the voltage enough to make it work again...but not for very long.
     
  6. Nov 21, 2016 #5

    sophiecentaur

    User Avatar
    Science Advisor
    Gold Member

    Except that the remote is OFF when no button is being pressed. Each time you press a button, you are turning it on.
     
  7. Nov 21, 2016 #6

    phinds

    User Avatar
    Gold Member
    2016 Award

    I've had this happen many times. Don't even need to remove the batteries, just rotate them slightly.
     
  8. Nov 21, 2016 #7

    russ_watters

    User Avatar

    Staff: Mentor

    We would have to know what kind of remote to be sure about that. My Logitech Harmony remote is computer driven and gos to sleep after a few seconds if no button is pressed, but only reboots if you take out the batteries (or drop it on the floor :mad: ). I expect most modern smart remotes are the same in that regard otherwise they wouldn't be able to remember what your entertainment center is doing.

    So yeah, it could be a lock-up/malfunction.
     
  9. Nov 21, 2016 #8

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    You use that trick, too?
     
  10. Nov 23, 2016 #9

    sophiecentaur

    User Avatar
    Science Advisor
    Gold Member

    Interesting. I've never come across that. I thought all the intelligence lay within the 'playout' units. I wonder what your remote has to do that requires constant power. I seems like it could benefit from a charging dock. Is it a Bluetooth system? That could explain it.
     
  11. Nov 23, 2016 #10

    russ_watters

    User Avatar

    Staff: Mentor

    I'm not sure it requires constant power, but it does require non-volatile memory and intelligence beyond a normal remote. It remembers the state/mode/input every device is in so it can execute sequences of commands with one button press. For example, when I hit the "watch TV" button, it turns on my TV, DVD player/receiver (in HDMI pass-through mode) and cable box. Then if i hit "watch a movie", it remembers that previous state and takes the appropriate actions: it turns the cable box off, changes the DVD player mode to "dvd" and doesn't touch the TV.

    It also has motion sensors on it so it comes alive as soon as I pick it up (it lights up), which is nice in a dark room.
    http://www.logitech.com/en-us/product/harmony-remote-650
    No, it's a normal IR "smart" remote. The battery life is surprisingly good.
     
    Last edited: Nov 23, 2016
  12. Nov 23, 2016 #11
    The battery will reach a state where it fails because the voltage supplied to the electronics is just a fraction too low for it to work. The battery contacts will have a resistance, albeit incredibly low, but enough to cause a minute voltage drop. Rotating the batteries will reduce that resistance by effectively cleaning the contacts of oxides or minute amounts of corrosion, the result being that the voltage drop is lower at the contacts and presents a higher voltage to the electronics... enough for it to come back to life.
    Just to add that most remotes will still consume power even when a button is not pressed; a very , very small current- but enough to discharge a battery over a few years in a very basic remote. Ever taken batteries out of an old remote and found them dead - or even leaking, yet batteries left in a drawer will almost certainly be ok.
     
  13. Nov 23, 2016 #12

    marcusl

    User Avatar
    Science Advisor
    Gold Member

    Had that problem with Vizio remote that would stop controlling TV, but the buttons still lit up so the batteries were fine. Customer Service said it was a malfunctioning chip in the remote. Removing and replacing batteries caused a reboot and it would work for a while before locking up again. They sent a new remote under warranty.
     
    Last edited: Nov 23, 2016
  14. Dec 17, 2016 #13
    I remember this was happening to me back at the 80s where the remote was certainly not smart. Plug in and out the batteries or rotating them worked fine for a period of time (like 1 week at most). Replacing batteries with new ones solved the problem completely.
     
  15. Dec 18, 2016 #14

    Svein

    User Avatar
    Science Advisor

    I seem to remember that contacts need a certain amount of current in order to keep them clean. So if the remote does not draw any current when not used, the contacts will corrode.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Why removing and replacing remote battery makes it work?
  1. How do battery works? (Replies: 2)

  2. Battery replacement (Replies: 36)

Loading...