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Is it Time to Change the 12V Battery ?

Discussion in 'Gen 2 Prius Technical Discussion' started by wirelessjava, May 22, 2023.

  1. wirelessjava

    wirelessjava Member

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    Hello Bisco and Prius Friends


    I did the 12V Battery Check and my battery is at 11.4 or 11.6 not the nomral 12.2 or 12.6 I bought the battery from AAA I have been getting the prius Gen 2 reset dance ( Basically it is like someone pulled the plug on and off of your 12V prius )


    Should I change the battery? I do not know of AAA has a warranty on my battery?

    ---wire
     
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  2. bisco

    bisco cookie crumbler

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    it sounds like it. how old is it, maybe just needs a good charge
     
  3. dolj

    dolj Senior Member

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    Sounds like you should check the connections at the battery and also where the negative cable connects to the car.
     
  4. sam spade 2

    sam spade 2 Senior Member

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    How old is your battery ?
    How often is the car driven.....and how far ??
    And under what conditions are you measuring the voltage and with what kind of device ??

    The connection at both ends of the main cables needs to be checked, as well as the battery itself tested AFTER
    being fully charged with an external device.

    THEN the charging voltage needs to be checked with the car running (READY mode).
     
  5. wirelessjava

    wirelessjava Member

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    I think my battery is 2.5 years old and I have not been driving it many miles but only 5 miles per day.

    ==wire
     
  6. bisco

    bisco cookie crumbler

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    take it to auto zone for a charge and load test. maybe you need a maintainer to keep it charged
     
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  7. sam spade 2

    sam spade 2 Senior Member

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    That might not be enough to keep it charged.

    To repeat:

     
  8. wirelessjava

    wirelessjava Member

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    AAA battery sucks.... Although not technically a scam .. but they do purposely have SH*T batteries. Find a better replacement.
     
  9. bisco

    bisco cookie crumbler

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    i'd be surprised, but who knows? any warranty?
     
  10. wirelessjava

    wirelessjava Member

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    Wazzup Bisco...

    Triple A batteries are crap. I need to get a battery with a 7 year warranty. Any recommendations?
     
  11. bisco

    bisco cookie crumbler

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    no such thing. duracell may be 4 years. oem is 8 years iirs, but pro rata after 2 years. i went oem cause my first one lasted 7 years
     
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  12. sam spade 2

    sam spade 2 Senior Member

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    AAA likely does not use exactly the same battery over time nor from one state to the next.
    SO.....ALL of the ones they supply are not likely to be "crap".

    Then.....the length of the warranty bears NO direct relationship to the quality of a battery.
    It is mostly a marketing gimmick.

    AND the longer warranties are almost always "pro-rated" after a couple of years and
    are based on the "list price". So if it fails after 4 years, the warranty price might actually
    end up being higher than the "off the shelf" current price for the same battery.
     
  13. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

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    AAA very likely supplied you with a quality battery; your expectations are the issue here: if you’re low usage and pay no attention to it, any battery is going to die in short order.

    See post #6. If you’re low usage you HAVE to get cagey with batteries. They will die if you’re low/sporadic use, and don’t take measures. Read up, get a smart charger (and use it), maybe an electronic load tester too so you will know where it’s at.
     
    #13 Mendel Leisk, Jun 1, 2023
    Last edited: Jun 1, 2023
  14. rjparker

    rjparker Tu Humilde Sirviente

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    You have to understand the car draws current from the 12v battery all the time. But it only charges it while you are using the car.

    Second, the battery may have been low when you got it or there may be something drawing more off state current than normal. This can be checked. If an excessive parasitic draw exists, a new battery will exhibit the same behavior.

    Finally a load test can verify the condition of your battery and it is often free at auto supplies. A parasitic draw test is easy for a mechanic but will cost a little.
     
    #14 rjparker, Jun 1, 2023
    Last edited: Jun 1, 2023
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  15. Prius DIY nut

    Prius DIY nut Member

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    I have more than 11 years old original battery in my 2012 Prius. I asked my local Canadian Tire store to load test it and they said it is still good. Anyone else is using their old original battery of 11+ years with no issues, is it ok to continue using it or better replace with a new one?

    If you curious why I am asking, it is because I started checking the auxiliary battery after ABS unit pump faulting concerns, I got long (20sec) pump run while opening driver door first time in a day. After charging the battery the run time went down to almost normal, about 7-10 sec.
     
  16. dolj

    dolj Senior Member

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    This is a Gen 2 thread and you're tagging onto it asking for information about a Gen 3. The design in this area is different between these two generations. It would be better to find a thread in one of the Gen 3 forums or even start your own thread over there so you get information relevant to your generation of Prius.
     
    Prius DIY nut likes this.