1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Remote Battery getting exhausted

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by itengineer, Apr 7, 2015.

  1. itengineer

    itengineer Member

    Joined:
    Oct 23, 2011
    83
    25
    2
    Location:
    Minneapolis
    Vehicle:
    2011 Prius
    Model:
    Two
    Hi All,

    The battery in my remote appears to be getting exhausted quickly.
    The fist time it happened was in 2014 when batteries on both remotes got spent. (for a 2011, I figured that it was normal).

    I picked up a 8 pack from Amazon and replaced batteries on both remotes but the frequency of exhaustion has increased dramatically.

    In fact, the last battery on my main remote only lasted 2 weeks.

    I have only been using the batteries from the pack I got from Amazon and it is entirely possible that I got a bad pack but are there any other theories out there ?
     
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,464
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    buy different batteries and see if it changes. fob batteries don't drain that quickly
     
  3. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    257
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    But when you get 8 from Amazon for $4......those often do. :(
     
  4. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
    4,365
    3,209
    1
    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    I have a customer with a fob that just began having a similar battery drain issue. Batteries lasting 2 weeks or less. Has gone through two of them so far. Got them both from the local hardware store which is reputable.

    Tried their secondary fob, and that one does not seem to have the battery drain issue.
    Checked all the buttons and they seem to be operating (clicking) just fine. LED light comes on only when a button is pressed.
    Now is trying to determine if it is the fob itself, or just some sort of issue between the fob and the Prius.

    Is currently trying this:
    Put new battery in the fob.
    Put the fob at the far end of the house (after confirming that the fob cannot communicate with the car)
    Wait two weeks.
    See if fob battery has drained at all.

    Please keep us updated with your experience/resolution.
     
    gdanner likes this.
  5. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    257
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    Places like that don't typically sell a lot of those kinds of batteries.
    Batteries have a shelf life.......no matter how reputable the store is.
    Were the new batteries tested at all before installing ??
     
    kenoarto likes this.
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    test them. someone else said amazon batteries were only 3 volts.
     
  7. itengineer

    itengineer Member

    Joined:
    Oct 23, 2011
    83
    25
    2
    Location:
    Minneapolis
    Vehicle:
    2011 Prius
    Model:
    Two
    They're supposed to be 3V. My Amzn battery read 3.3V but it still failed after 2 weeks. I just put a different one in bought at a local store.
    We'll see how this one performs.
     
  8. FrankB

    FrankB Member

    Joined:
    Dec 12, 2012
    117
    53
    1
    Vehicle:
    2010 Prius
    Model:
    II
    FWIW, make sure the foam in the FOB is in the correct place over the battery as I had trouble with going through batteries quickly (more than two weeks but less than a year) when the foam was out of place.
     
  9. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
    4,365
    3,209
    1
    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    Batteries were tested ahead of time.
     
  10. Jim T

    Jim T Junior Member

    Joined:
    Apr 8, 2015
    22
    11
    0
    Location:
    New York State
    Vehicle:
    2010 Prius
    Model:
    II
    One of my key fobs developed the same problem. I kept the fobs at the far end of the house from the garage and away from electronics but it still depleted the battery in just weeks. I burned through one or two Energizer CR1632's from a 100% rated high volume Amazon seller, but still wondered was it bad batteries? Took it to the dealer and they required putting their own battery in so I had to come back a couple weeks later for them to verify the voltage was low. The key fob was replaced under warranty as I was still within a year on my certified used purchase.

    My remaining original fob lasted 6 months of active use on a new battery before getting a low battery message on the car display. I'm now at 7 months use on my replacement fob on a battery that was replaced 14 months ago.
     
  11. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    2,642
    1,133
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    But the shelf life of those batteries is several years without drastic deterioration.
     
  12. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
    4,365
    3,209
    1
    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    It's good (I guess?) to confirm that others have experienced mysteriously draining fobs.
    Would be nice to get to the bottom of exactly how/why they are draining. Seems a waste to get rid of it if the problem could be easily fixed.
     
  13. Jim T

    Jim T Junior Member

    Joined:
    Apr 8, 2015
    22
    11
    0
    Location:
    New York State
    Vehicle:
    2010 Prius
    Model:
    II
    My service notes on the warranty replacement just stated "internal short"
     
  14. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it's difficult with limited communication from the o/p.
     
    #14 bisco, Apr 9, 2015
    Last edited: Apr 10, 2015
  15. Siward

    Siward Active Member

    Joined:
    Aug 7, 2014
    296
    124
    10
    Location:
    Toronto
    Vehicle:
    2012 Prius
    Model:
    Three
    Are you leaving your keyfob near your car? I once had a Prius brochure that told me never to leave my keys within 2-3 meters of the car as it drains the battery due to the smartkey system.
     
  16. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    why would that be a problem?
     
  17. itengineer

    itengineer Member

    Joined:
    Oct 23, 2011
    83
    25
    2
    Location:
    Minneapolis
    Vehicle:
    2011 Prius
    Model:
    Two
    UPDATE:
    So, the fresh battery (purchased from a quality local store) that i put in on Tuesday was all spent today(Friday)
    I measured the voltage on Tuesday and again on Friday
    Tuesday: 3.3V
    Friday 2.58V

    The remote would not function with the 2.58V battery. I think I can rule out the quality of the batteries as a factor.
    Also, since this is happening to both FOBs, i am going to rule out an internal short as a cause.
    I am leaning towards RF interference from the phone and/or WiFI. I know that the iPhone and the keys sit in the same pouch of wife's handbag sometimes touching each other. I also recently moved the WIFI router to my main living room from upstairs.

    I have turned off bluetooth on the iPhone. I will also try to get a RF shielding pouch to store the keys in.
    More to follow.
     
  18. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    do you live near a defense installation?
     
  19. itengineer

    itengineer Member

    Joined:
    Oct 23, 2011
    83
    25
    2
    Location:
    Minneapolis
    Vehicle:
    2011 Prius
    Model:
    Two
    No, live in Suburbia.

    it could be the communication with the Prius - not sure what it does exactly
     
  20. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    the car continually seeks the fob 24/7. when the fob is in range, they communicate with each other. normally, the battery lasts 3-5 years, depending on how much you drive. if you keep it at the other end of the house, there is something else that is causing it to activate. as the manual states, cell phones, cordless phones, other fobs, what have you. if not, then something in your circuit board has gone bad.
     
    gdanner likes this.