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

Smart keys eating batteries

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by ewmaher, Nov 20, 2013.

  1. ewmaher

    ewmaher Junior Member

    Joined:
    Jan 26, 2011
    6
    0
    0
    Location:
    Upstate New York
    Vehicle:
    2010 Prius
    Model:
    III
    The batteries in both of my smart keys for my 2010 Prius died this past year. Both keys now chew through new batteries in about a week. It's really ticking me off.

    Anyone else experienced this? Is there a solution?

    Thanks!
     
  2. jdcollins5

    jdcollins5 Senior Member

    Joined:
    Aug 30, 2009
    5,131
    1,338
    0
    Location:
    Wilmington, NC
    Vehicle:
    2010 Prius
    Model:
    III
    No. The SKS batteries should typically last about 3 years. Are you checking the voltage of the replacement batteries before using? They do have a limited shelf life.

    If they continue to drain batteries you may want to have the dealer check your system.
     
  3. dkelly

    dkelly Member

    Joined:
    Apr 30, 2010
    118
    14
    0
    Location:
    Gilbertsville, PA
    Vehicle:
    2010 Prius
    Model:
    V
    I recall reading somewhere (perhaps the owner's manual) that you need to be cautious about storing the keys too close to the car. If close enough, the keys could continually communicate with the car, shortening the battery life. Have you changed where you store your keys?
     
  4. swordsintoplowshares

    swordsintoplowshares Junior Member

    Joined:
    Nov 19, 2013
    7
    0
    0
    Location:
    North Carolina
    Vehicle:
    2010 Prius
    Model:
    II
    The owners manual also says not to store key fob within 3 feet of a battery charger (cell charger?), lamp or TV because of the emission of electrical signals that can cause the key fob to activate and drain the battery
     
  5. ewmaher

    ewmaher Junior Member

    Joined:
    Jan 26, 2011
    6
    0
    0
    Location:
    Upstate New York
    Vehicle:
    2010 Prius
    Model:
    III
    I haven't changed my habits as far as I am aware. It doesn't seem right that you need to be so careful with the smart key.
     
  6. jdcollins5

    jdcollins5 Senior Member

    Joined:
    Aug 30, 2009
    5,131
    1,338
    0
    Location:
    Wilmington, NC
    Vehicle:
    2010 Prius
    Model:
    III
    It is just that if you are in range of the car with the key the SKS ECU is constantly communicating with the key.
     
  7. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,801
    48,999
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    my batts last forever, and they hang with 2 other hybrid sets next to the cell and charger. about 12' from the car.
     
    GrumpyCabbie likes this.
  8. Paul R. Haller

    Joined:
    Jun 13, 2005
    285
    41
    0
    Location:
    Walnut Creek
    Vehicle:
    2006 Prius
    Model:
    N/A
    I had the same problem with my 2006 Prius. It turns out they were in my pocket with all kinds of other stuff like keys and phone. Anyway, something was keeping my fob button pressed all day. The fob was a 1/4 mile away from the car so no problems except my having to replace the battery weekly.
     
  9. southjerseycraig

    southjerseycraig Active Member

    Joined:
    Jan 23, 2009
    438
    107
    0
    Location:
    Cherry Hill, NJ
    Vehicle:
    2010 Prius
    Model:
    II
    A tech claimed to me that proximity to a cellphone will also shorten battery life.
     
  10. Former Member 68813

    Former Member 68813 Senior Member

    Joined:
    Oct 3, 2010
    3,524
    981
    8
    Location:
    US
    Vehicle:
    Other Hybrid
    Model:
    N/A
  11. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,801
    48,999
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    sometimes, you just can't protect people from themselves.:rolleyes:
     
  12. macman408

    macman408 Electron Guidance Counselor

    Joined:
    Mar 21, 2010
    1,179
    365
    1
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    V
    Yeah, proximity to cell phones, the car, and any other electronic device could cause the battery to drain very quickly. That's certainly not the common case (my key is usually close to my cell phone and other electronics), but it happens sometimes, so they mention it as a possibility in case you have problems.

    If it's both keys, and no habits have changed, I'd wonder about the batteries you're getting. Maybe they stink? Maybe they were sitting on the shelf (either yours or the store's) for a few years to long?
     
  13. Les_PL

    Les_PL Active Member

    Joined:
    Nov 11, 2012
    317
    248
    0
    Location:
    Gdynia, PL
    Vehicle:
    2009 Prius
    Model:
    III
    Perhaps they are stored in some kind of pouches (did you buy recently new ones?) where the buttons are pressed by some shape of design?
     
  14. icspots

    icspots Junior Member

    Joined:
    Nov 8, 2013
    41
    22
    0
    Vehicle:
    2012 Prius c
    Model:
    Four
    If you're not using the keys for an extended period there should be a way to make the key go to sleep. I read it briefly in our C manual, but I don't have it with me. Basically some combination of pressing remote buttons turns off the SKS functions until one of the buttons is pressed again. Perhaps try doing that when you hang your keys up and then tap a button when you pick them up in the morning and see if it improves your batter life?
     
  15. Danger

    Danger Member

    Joined:
    Jun 8, 2011
    175
    22
    6
    Location:
    Frisco
    Vehicle:
    2010 Prius
    Model:
    IV
    I can tell you my personal experience is to not cheap out on the batteries. I bought some cheap brand on eBay and they only lasted 1-2 months. I even carefully cleaned the insides to make sure it wasn't some internal problem. I caved in and bought some brand name batteries and I will wait to see how long these last. I am hoping for 1-2 year mark.
     
    ftl likes this.
  16. adamace1

    adamace1 Senior Member

    Joined:
    Jun 22, 2009
    1,403
    191
    0
    Location:
    Charlotte, NC
    Vehicle:
    2010 Prius
    Model:
    II
    Bad batteries? If the old ones lasted years i'm thinking the new batteries are not good.
     
  17. rrg

    rrg Active Member

    Joined:
    May 18, 2010
    458
    120
    41
    Location:
    East coast - NJ
    Vehicle:
    2011 Prius
    Model:
    Two
    My daily fob battery is just starting to go dead. The car shows Low Key Battery on the display.
    It's been 2.5 years. The range has also diminished lately.
     
  18. Hi There

    Hi There New Member

    Joined:
    Mar 24, 2014
    1
    0
    0
    Vehicle:
    2011 Prius
    Model:
    II
    I also had a problem with my smart key dying. I bought my Prius in late November 2011. A month ago the battery on the smart key went dead. I replaced it with the exact same battery, Panasonic CR1632, and kept the fob as far away from cordless and cell phones and lamps and TVs as possible (though I don't think this is practical for normal use). The replacement battery also died a week later. I gave it a new replacement battery. That one died in a week too. Throughout this time, the spare smart key has functioned normally. I brought the smart key to the dealership and they replaced it with a new one, saying that a parasitic draw within the smart key was causing rapid battery discharge. They advised me to keep the replacement smart key at least 10 feet away from all cordless and cell phones. I don't see how I could possibly abide by that advice. Good thing it was under warranty, or I would likely have had to pay $500 to have it replaced. I expect the replacement will likely last another 2.5 years and then I'll have to pay that $500.

    The smart key was not kept in close proximity to the car. There were no other objects pressing on the smart key buttons constantly. Both replacement batteries had an expiration date of 2023.
     
  19. Cjeigh

    Cjeigh Junior Member

    Joined:
    Dec 13, 2013
    45
    6
    0
    Location:
    Winnebago, IL
    Vehicle:
    2010 Prius
    Model:
    III
    Same here.
     
  20. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

    Joined:
    Oct 9, 2012
    1,179
    289
    0
    Location:
    Northern California
    Vehicle:
    2012 Prius
    Model:
    Plug-in Base
    I keep the key fob in the car 99% of the time in the garage. 1 year and no problem but I do have spare battery in the glove box because if the fob went dead while on a trip it would be bad news.