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Replaced AUX Battery MPG Sucks Now!! 2008 131,000 miles

Discussion in 'Gen 2 Prius Main Forum' started by NinnJinn, May 25, 2017.

  1. NinnJinn

    NinnJinn Member

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    I have a 2008 prius with SKS and it has 131,XXX on it. 3 weeks ago my 12v Aux battery was totally dead. I jumped it all was good. But went ahead and ordered a Yellow top Battery got it next day and installed it.

    I have a scanguage from day 1.

    Since I have installed the yellow top battery, my MPG has dropped 10+ miles! it seems my battery pack is working more according the the MFD, Weather is a little warmer (70-75) no rain, no AC, same commute. Everytime I get in my car in the morning Scan gauge says SOC is anywhere from 47-51% it used to range 58-61%.

    Before Yellow top, SOC would get up to 64% in a matter of 2-3miles. Now, I'm lucky to see 58% after 20miles of HWY speeds... While driving at HWY speeds: Before Yellow top, SOC was typically between 61-64. After Yellow top, SOC is 54-57%

    No sporadic changes in SOC. still -.1% every second while in stealth mode. And still +.1% every second coasting.

    Never gotten the triangle of death.
    Check Engine is throwing a P1116 code for the coolant valve to the thermos which has been like that for the last 2-3 years.

    Is it time for a new HV pack before this one totally dies and leaves me stranded?
     
  2. bisco

    bisco cookie crumbler

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    did you check the voltage, or charge it up before installing?
     
    Mendel Leisk likes this.
  3. dolj

    dolj Senior Member

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    I wouldn't worry, removing the 12 V power resets, among other things, the fuel trims back to default. Within the next month the car will relearn the fuel trims and you'l be back to normal. The adverse affect of the reset is that the onscreen average consumption reads a little low to start with.

    I'd only be worried if your calculated tank averages tanked. (Did you see what I did there? LOL.)
     
  4. Sam Spade

    Sam Spade Senior Member

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    ^^^^^^ This.

    But the new 12 v needs to be fully charged with an external charger, no matter what brand and type it is.
    Now is not too late to do that.