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Replaced 12v battery - MPG increased - another anecdote

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by yossi, May 17, 2021.

  1. yossi

    yossi Junior Member

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    I recently got a 2008 with 189k miles. The 12v was original. I was not having any issues, no dash lights or any indication the battery was failing, but when I ran the on screen diag, it showed it at 10.7 volts. So I had the dealer replace it with a new Toyota, $250 out the door. My average MPG has gone up from around 43 to around 48. I notice the car lasts longer on hybrid battery only, especially when I have cruise control engaged on a flat road and locked in at 35-40. Just wanted to share my experience.
     
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  2. bisco

    bisco cookie crumbler

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    that's amazing!

    1) 13 year old oem still working

    2) dealer install for $250.

    3) mpg increase

    4) you hit the trifecta!(y)
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe. How would you know for sure? Either way, it was time. :)
     
  4. archae86

    archae86 Member

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    A long time ago I had a Sears Diehard last 10 years in my 1987 BMW 325i. When I looked in my glove compartment for my battery paperwork, I found the 10-year-old paper and just assumed that since the battery could not possibly have lasted that long I must have mislaid the more recent paperwork. But when they took my old battery out of the car they pointed out that there was a manufacturing date code on the battery which was consistent with my approximately 10-year-old timing. So far that is my lifetime best battery time.

    Is it normal for automotive batteries to carry a manufacturing date code these days?
     
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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    I’ve heard yes, but sometimes it’s a code, maybe to discourage “cherry picking”, like when you’re buying groceries, looking for the latest best-by dates.
     
  6. yossi

    yossi Junior Member

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    Dealer confirmed based on manufacture date on battery.
     
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  7. bisco

    bisco cookie crumbler

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    toyota date code is on top, and not really a code, just the date in numbers and letters.

    you do have to remove the hold down bracket to see it
     
  8. dolj

    dolj Senior Member

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    Just numbers actually in the format ddmmyy.
     
  9. Pdaddy

    Pdaddy Member

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    Warmer weather has a significant positive effect on efficiency

    SM-G960U ?
     
  10. Grahams Number

    Grahams Number Junior Member

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    Another thought...unplugging battery reset engine ecu. I *think* the ecu learns your driving style and specific engine parameters. It will take several days to relearn
     
    #10 Grahams Number, May 20, 2021
    Last edited by a moderator: May 21, 2021