Do I need a new 12v battery?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by BlueV15, Sep 7, 2025 at 11:30 AM.

  1. BlueV15

    BlueV15 Junior Member

    Joined:
    Nov 6, 2023
    26
    10
    0
    Location:
    Southern California
    Vehicle:
    2015 Prius v wagon
    Model:
    Two
    I've read some stuff about checking the 12v battery and I did a test over 3 days with the car off.

    After 24 hours - 12.2v
    After 48 hours - 12.2v
    After 72 hours - 12.18v

    I can't find a date on the battery, but it's a Toyota battery, so it may be the original battery. The car starts and runs normally and nothing seems out of the ordinary. Do I need a new one or can I stretch this one out longer?
     
    #1 BlueV15, Sep 7, 2025 at 11:30 AM
  2. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    9,807
    6,048
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    10 years is stretching it a bunch. The problem is an old battery on a Prius is not obvious with signs like slow cranking. As a result you could drive it 5 miles and park it at the grocery store or mall only to find yourself with a no start 1 hour later.

    But there is a test and it is not voltage readings over time. It is a load test free at most auto supplies.
     
    #2 rjparker, Sep 7, 2025 at 11:39 AM
    BiomedO1 likes this.
  3. ColoradoBoo

    ColoradoBoo Senior Member

    Joined:
    Jul 19, 2019
    1,180
    766
    4
    Location:
    Monument, Colorado USA
    Vehicle:
    2017 Prius
    Model:
    Two
    Yep, visit your dealer and buy a Toyota TrueStart....comes with an 84-month warranty! (Last year, I spent $208 for one for my daughter's 2017 Prius.)
     
    #3 ColoradoBoo, Sep 7, 2025 at 12:13 PM
  4. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,005
    1,609
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    Yep, get it load tested at any auto parts store to confirm it's validity.
    Keep an eye out for future sales and maybe buy a cheap jump-box, just in case you get stranded some place.

    Good Luck....
     
    #4 BiomedO1, Sep 7, 2025 at 12:52 PM
(You must log in or sign up to post here.)