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12 volt battery advice

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Paul E. Highway, Aug 21, 2021.

  1. Paul E. Highway

    Paul E. Highway Active Member

    Joined:
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    Location:
    Hawaii
    Vehicle:
    2010 Prius
    Model:
    Four
    Aloha!

    My 2010 Prius has 167K and is on it’s 2nd 12 volt battery (I think). I’m second owner, bought in 2019. Car sold new fall of 2009, assume OEM battery went 6 or 7 years, that would put this battery at 5-6 years old. No stickers on battery showing date of install.

    Yesterday I checked voltage (without key fob present) and got 12.66 volts. Did not drive car, today got 12.45 volts and then 12.08 volts with headlights on.

    Any comments on probable life of this battery? I’m a big believer in preventative maintenance and would want to replace with OEM before it starts acting up.

    Batteries here in Hawaii are exposed to medium humidity and temperature from 70F-90F every day of the year.

    Any thoughts appreciated!

    PEH

    upload_2021-8-20_21-23-44.jpeg C77CA9E8-6186-45FF-8563-634F3F4C59A0.jpeg 7A355BF1-7BEF-450C-A1E4-A04900E751C4.jpeg
     
    #1 Paul E. Highway, Aug 21, 2021
  2. james nancy

    james nancy Member

    Joined:
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    Location:
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    Vehicle:
    2010 Prius
    Model:
    III
    I don’t know much, but I feel that the battery is okay, because as long as it is ready, the hybrid battery will charge it
     
    #2 james nancy, Aug 21, 2021
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    If your usage is low, AND you have convenient/secure 120 volt AC, I’d heartily recommend a smart charger, one that’s safe to leave on constantly.
     
    #3 Mendel Leisk, Aug 21, 2021
  4. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
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    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Nice work with the warranty hv pack and brake booster. You are probably good for an another year on the 12v battery especially when reading 12.66v at rest. The best test is an auto supply load test, often free.

    I would buy a $100 Noco Jump Pack and keep it in the car as backup. The advantages of a jump pack include the ability to help someone else without risking your electronics through a conventional jumper cable hook up.

    Inadvertent reverse polarity jumps can be serious even if it just blows fuses and fusible links.
     
    #4 rjparker, Aug 21, 2021
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    We had the power go out, yesterday IIRC. Had an epiphany:

    806CBE99-95A4-4DD2-A461-559DA86E39EC.jpeg
     
    #5 Mendel Leisk, Aug 21, 2021
  6. sam spade 2

    sam spade 2 Senior Member

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    Four
    That's a pretty big drop.
    Given the maintenance philosophy that you have, I suggest ordering one NOW......because in some places the wait to get one is several months.
    But the suggestion about a battery tender is also a good one, partly because it should be fully charged before you embark on any kind of tests.
     
    #6 sam spade 2, Aug 21, 2021
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