My 12V Battery is dying

Discussion in 'Gen 5 Prius Care, Maintenance and Troubleshooting' started by priusasa, Dec 13, 2025.

Page 4 of 4
  1. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,708
    1,924
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    According to the Napa website that's a 70Ah battery; whereas Toyota specifies 45Ah minimum. So not sure what your asking? Does it not strap-down properly?
    https://www.napaonline.com/en/p/BAT7548
     
    #61 BiomedO1, Dec 31, 2025 at 1:39 PM
  2. priusasa

    priusasa Member

    Joined:
    Dec 28, 2024
    83
    35
    0
    Location:
    02149
    Vehicle:
    2023 Prius
    Model:
    LE
    So my battery group size is LN3 as you can see
    But manual says "Use a battery that the case size is same as previous one (LN1)

    So, this car is Toyota Certified and I think they should have used the correct battery type at least. When I research more information about it, it should not able to fit there but its there. Interesting.
     
    #62 priusasa, Dec 31, 2025 at 2:29 PM
  3. Mendel Leisk

    Mendel Leisk MMX GEN III

    Joined:
    Oct 17, 2010
    60,386
    41,553
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Are the dimensions roughly the same, the fiddly-design Toyota hold-down bracket fits (maybe with a washer or two)? It meets or exceeds electrical spec's? Then it's "correct".
     
    #63 Mendel Leisk, Dec 31, 2025 at 2:33 PM
  4. priusasa

    priusasa Member

    Joined:
    Dec 28, 2024
    83
    35
    0
    Location:
    02149
    Vehicle:
    2023 Prius
    Model:
    LE
    I am not sure how they fit it there, but other features exceeds since LN3 actually is bigger battery. So according to manual, its the only "size" is wrong.

    When I first realized that, which is today, I though that they are completely diffrent and you should not use different group type. But it was actually just a dimention thing.
     
    #64 priusasa, Dec 31, 2025 at 2:42 PM
  5. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,708
    1,924
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    It does exceed OEM specifications; so the real questions is: does it strap-down and vent properly in it's OEM position? The 2023 Prius battery got moved back into the trunk; correct? If that battery is under the hood, you can forget about item #2.
    1. If it isn't properly strapped-down; it can rock around, loosen and/or break connections.
    2. It needs to vent properly, since it's technically located in the cabin. There should be a vent hose connected to the battery so it can vent hydrogen out of that compartment (by-product of charging) - explosive hazard.
    If that battery doesn't meet either of the above criteria, you've got a very good claim against the dealership for something that will actually meet both those criteria. That would make it a consumer protection and safety issue claim.

    Good Luck.......
     
    #65 BiomedO1, Dec 31, 2025 at 3:54 PM
    Last edited: Dec 31, 2025 at 4:06 PM
  6. CooCooCaChoo

    CooCooCaChoo Senior Member

    Joined:
    Jan 7, 2015
    958
    535
    0
    Location:
    Cow-lee-fornia
    Vehicle:
    2023 Prius
    Model:
    LE
    Yeah, OEMs are Panasonic or some other Japanese brand, not Napa. You could hassle them to replace it, but most likely they won't budge because it's working and not defective.
     
    #66 CooCooCaChoo, Dec 31, 2025 at 6:26 PM
(You must log in or sign up to post here.)
Page 4 of 4