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Gen 2 2008 12volt battery question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jennifer VonIngelheim, Aug 13, 2024 at 7:01 PM.

  1. Jennifer VonIngelheim

    Jennifer VonIngelheim Junior Member

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    Hi everyone!
    I need to change my 12v battery, it's at 11.4% per Dr. Prius. It did not throw a code for that. I am getting a refurbished EV battery installed in two days. I believe the 12v battery should be replaced too. Need advice on that and advice of a 12v battery that doesn't cost $250+. Already spending $1500 on EV.
    Thanks!!
    Jen
     
  2. Tombukt2

    Tombukt2 Senior Member

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    I don't know Just look online for our battery size there are some options I think they're all about $180 if you shop carefully the die-hard in the silver blue label looking business maybe with gold writing of die hard so that makes it a die-hard gold I bought one not long ago for 184.63 carrying it out of the store brand new That's a reasonably good battery in my book they do make better but there's no reason to spend that kind of money on such a small 12 volt there are other tricks other people are using some are using elevator batteries The batteries that go in those boxes that turn lights on when there's a fire in the building they called them UB universal batteries but I don't think you want to get into all that business you just want to straightforward swap and that'll be the way to go so give that a try That's a little bit less than your 250 for the diehard.
     
  3. Brian1954

    Brian1954 Active Member

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    Check your local Walmart for the 12v battery. In my area it costs $180.
     
  4. bisco

    bisco cookie crumbler

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    some people use a small inexpensive tractor battery or the like. you would have to alter the hold down bracket, and possibly the terminals rings.
    there are a few threds here if you can find them.
    how old is your 12 volt? does the car start?
     
  5. MAX2

    MAX2 New Member

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    How does one assess Dr. Prius the condition of a 12V battery?
    The condition of the battery is assessed by the voltage after charging it.
    Or a special device that determines its internal resistance in conjunction with voltage.[​IMG]
     
  6. pasadena_commut

    pasadena_commut Senior Member

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    I don't trust these small electronic testers very much. Our 2007 had been on a lot of short trips lately and the Viking tester

    12V Digital Battery and System Tester

    put up a "replace battery" with a set of terrible numbers, 12.3V and SOH 10%, capacity 7AH, and so on. So I charged the battery for most of the day and retested it. 12.55V, SOH 90%, capacity 45AH, and all good.

    But it wasn't apples to apples. The first test was attached at the front jump post, and the second attached to the clamps on the battery (where the charger had been attached). This tester can make mediocre electrical connections:

    What causes the voltage drop between the 12V and the jump post? | PriusChat

    and I don't think it did a great job clamping onto the jump post. That wouldn't have affected the voltage measured, but the internal resistance and load testing (such as it is) was probably not very accurate.

    Note, in both cases the test started about 1 second after a 20 s discharge with the headlights, so there was some voltage depression factored in, I didn't let the battery rebound to whatever its original voltage was before running the test.