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Dead 12 volt battery after ECU Update

Discussion in 'Gen 3 Prius Technical Discussion' started by jorez, Apr 14, 2014.

  1. jorez

    jorez New Member

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    Location:
    White House, Tennessee
    Vehicle:
    2011 Prius
    Model:
    II
    I got the ECU Update Friday.. Today my 12 volt battery died.(got it started after a jump)..Any correlation?? Toyota service days no. Is there any kind of a warranty on the 12 V battery? 2011 with about 40k on it seems way low for the battery to die. No changes in driving habits since ECU update either...ARGHHH!!!
     
  2. bisco

    bisco cookie crumbler

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    they probably left the door open and interior lite on while they had it. of course it's their fault, but they'll never admit it. the worst part is that running these batteries down affects their longevity. i would go back and fight with them. all the best!(y)
     
    WE0H likes this.
  3. mroadster2k

    mroadster2k A little bit of awesomeness

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    Vehicle:
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    Not too sure, but I took my '10 for the ECU update recall, and ended up paying for a new 12V battery. The car has 49.5k miles, but the dealer said that I'd needed a 12v battery replacement, since the old battery would not "take" the ECU upgrade. Though the battery reading were on the lower side of the range, I figured to just replace it and save myself the headache.

    The 12V batteries are not covered by a warranty outside of the 36k mile warranty, but replacement batteries have a 4 year warranty. Makes no sense to me.
     
  4. bisco

    bisco cookie crumbler

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    good idea replacing it on the '10, they have had a ton of failures.
     
  5. Tom N55

    Tom N55 Junior Member

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    Vehicle:
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    Is there a way to test your 12 volt battery while it is in the car? I am beginning to suspect that my battery is starting to fail on my 2010 Prius. BTW, I wish there was a better attachment point for jump starting...:-(
     
  6. FrankB

    FrankB Member

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    If you have a multimeter, you can measure the voltage either on the battery terminals or on the jump starting terminals under the hood. Let the car sit for a few hours after last use. Measure the DC voltage, if it's under 12.0 think about when you might like to do a replacement. If it's under 11.5 go ahead and replace it. There are some voltage charts around that show more levels to think about.

    Frank
     
  7. toyolover

    toyolover Member

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    Location:
    toronto, canada
    Vehicle:
    2010 Prius
    I had to replace my 12v battery at the 48th month. Most battery manufacturer websites I visited indicate it is quite normal. I guess some brands do have a longer warranty period but I'd suppose they won't hold that much juice as they were new. My recommendation is to install a new one after 4 years of usage because extending it another year does not justify the inconvenience of being stuck with a dead battery, especially when you live in the cold part of the country.