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

Key fob Requires battery change about every three weeks

Discussion in 'Gen 3 Prius Main Forum' started by ilovemymac, Sep 6, 2022.

  1. ilovemymac

    ilovemymac Member

    Joined:
    Mar 7, 2013
    170
    22
    0
    Location:
    Gardner, KS
    Vehicle:
    2010 Prius
    Model:
    V
    So I only have one key fob for my car and about six months ago the battery started dying about every three weeks or so. I don’t know why. I’ve even gone to the point of taking the battery out but I remember to at night sometimes and it doesn’t really extend it much may be a few days. I thought maybe V contacts inside needed to be cleaned so I can scrub them with a brush really good clean them and still no difference.

    Is there something I can do? A new key fob is expensive Toyota said they were over $200 I don’t really want to spend $200.
     
    Mambo Dave likes this.
  2. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,837
    1,828
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    You should spend the money for a second fob. If you lose the one you have, It becomes 10x the cost to get one (they have to replace the ECU).

    JeffD
     
    CooCooCaChoo likes this.
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,791
    48,994
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    stuck button?
     
    Pulse07 and CooCooCaChoo like this.
  4. Doug McC

    Doug McC Active Member

    Joined:
    Feb 15, 2022
    957
    353
    0
    Location:
    Midwest
    Vehicle:
    2022 Prius
    Model:
    XLE
    On our 2022 you can hold the lock button down and, at the same time push the unlock button twice. Keep holding the lock button until the red light on the fob flashes 4 times. This puts the fob effectively to sleep, conserving the battery.
    I have no idea if it works on earlier generations.
     
  5. MalachyNG

    MalachyNG Active Member

    Joined:
    Feb 6, 2019
    299
    218
    0
    Location:
    Northern NY
    Vehicle:
    2022 Prius Prime
    Model:
    XLE
    are you leaving the fob inside your car at night or do you keep your keys really close to it in the garage? if it's within range of the SKS sensors it'll drain the battery. There could be something causing a short inside the fob...You may went to spend that money now for a spare while your current one still works.
     
  6. AzWxGuy

    AzWxGuy Weather Guy

    Joined:
    May 22, 2011
    969
    490
    0
    Location:
    Tucson, AZ
    Vehicle:
    2021 Prius
    Model:
    Limited
    How close to your car is the fob? If we are talking Gen III Prius, and I think we are with a 2010, I seem to recall from the owners manual that the fob has to be within about 3 feet of the door to be unlocked. But sometimes the vehicle will ping the fob from further away several times a day causing it to power up and use battery energy. Those 3V lithium cells should last a good long time, like 2-4 years. Could be internal damage of the fob too, like if it got run through a washing machine in a pocket and wasn't allowed to dry properly. Look for etching on the internal printed circuit board or damaged electronic parts.
     
  7. Pulse07

    Pulse07 Active Member

    Joined:
    Feb 24, 2020
    273
    137
    0
    Location:
    East Bay, California
    Vehicle:
    2020 Prius
    Model:
    XLE AWD-e
    Are you purchasing cheap batteries? And $200 is considered a steal for a second keyfob (at least in my experience)
     
  8. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    8,131
    1,409
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Our 13 persona pretty much resides in the car all the time the remote that is doesn't seem to die it's been about a year and a half just sitting red light worked yesterday. Now my Gen 2 is a different story we won't go there but both remotes if you open them correctly there's a sticker inside with all the numbers that need to be fooled with to make this happen and I guessing all Gen 3's or SKS so they have a transponder chip more than likely even if the remote doesn't work anymore the transponder will still turn the alarm off in my other Priuses if they're SKS and you can drive the car you just wind up locking the car with the physical key which locks all the doors that one time when you do it still even if the remote doesn't work in my Gen 2 the remote hasn't worked in a long time but with the key in the slot the car is always beeping when you open the door because the transponder requires no battery just like my motorcycle No battery needed no remote transponder equals no power. I thank all that needs power in a locking and unlocking button pushing equal power.
     
  9. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    8,131
    1,409
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Call all lock and key in Maine USA I think he is . He can tell ya over phone. Nice guy.
     
  10. tak1313

    tak1313 Member

    Joined:
    Apr 7, 2016
    74
    34
    0
    Location:
    NH
    Vehicle:
    2010 Prius
    Model:
    III
    My wife's fobs were having that problem for awhile - until I figured out it was the battery. Cheap Ray-O-Vac batteries (et. al) would die in a few weeks. Switched to Energizer (be careful where you buy it from, as there ARE counterfeits on Amazon, etc.), and no problem since.
     
  11. ColoradoBoo

    ColoradoBoo Senior Member

    Joined:
    Jul 19, 2019
    914
    600
    4
    Location:
    Monument, Colorado USA
    Vehicle:
    2017 Prius
    Model:
    Two
    Yep those batteries don't last long...I replace ours about every year. And I second that advise to get a 2nd fob pronto....it's big bucks, no whammies, if you have NO fob and have to get the dealer to re-program your computer to use a new one!
     
  12. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,837
    1,828
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    My 2004 Fob Batteries lasted about 5 years as did my 2016 (never had to replace a fob battery) in the 4 years it lived)

    JeffD
     
  13. Yaesu

    Yaesu Member

    Joined:
    Nov 19, 2016
    106
    31
    0
    Location:
    Kentucky
    Vehicle:
    2010 Prius
    Model:
    IV
    I have two 2010 Prius's and the fob batteries last for several years. I made RF safe cases for them and leave the fobs in the cases, tucked in the little pocket in the driver's doors. Of course the vehicles are stored in a locked garage. Much simpler than having to remember to bring the fob with me to use the vehicles. I also keep the keys in all of my other vehicles as well as in the ignitions of my motorcycles. They are locked in the garages or barn. I do this incase I need to get them out of the buildings in a hurry due to a fire or other calamity.