A signal your 12V battery needs replacing

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PriusFruit, May 6, 2021.

  1. PriusFruit

    PriusFruit Member

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    After swapping out my 12v battery for a new one. I realized there was a sign ahead of time (possibly) that could've been a signal that my battery needs to be replaced.

    It has to do with the car alarm. I always had to be pretty close to my car to set the alarm. I mean within 5 to 8 feet. It was sometimes annoying, but I just thought it was because it was an older car.

    Now after changing the battery, the alarm seems to be a lot sharper. I'm able to set it from a lot farther away. I'm still testing this out to see if it's my own imagination or not lol. But this was definitely something I noticed and could be a sign your 12v needs to be replaced soon.

    Heads up, the way I found my 12v battery needed to be replaced was my alarm went off out of the blue. Then I went to start the car and all I saw was a flashing dashboard until the car was completely dead. Jumped the car, took it to the shop and got a new 12v battery...everything is back to normal and better now.

    Forgot to add that the old battery was 6 years old (previous owner).
     
    #1 PriusFruit, May 6, 2021
    Last edited: May 6, 2021
  2. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Look into electronic load testers.
     
  3. PriusFruit

    PriusFruit Member

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    What would I be testing with this? The battery?

    The mechanic I go to always does a load check with the battery and it came back positive before this happened. I should've added this to the op.

     
  4. bisco

    bisco cookie crumbler

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    is it an aftermarket alarm?
     
  5. PriusFruit

    PriusFruit Member

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    I don't think so, but I also wouldn't know. I'm the third owner.

    edit: the car has been great though!
     
  6. bisco

    bisco cookie crumbler

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    i don't have an alarm you set. whatever is in the car, arms itself when you lock the doors.
     
  7. Mendel Leisk

    Mendel Leisk Sand Pounder

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    You’re testing Cold Cranking Amps. Some argue it’s irrelevant, since the Prius doesn’t use the battery to crank. I think that’s beside the point: a viable battery will have Cold Cranking Amps at least as high as spec, typically higher.

    No idea if this is best option, but I’m using an earlier version of this one, works well, worth googling:

    Solar BA9
     
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