Hybrid battery cell or 12v battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by OldlinePrius, Aug 1, 2021.

  1. OldlinePrius

    OldlinePrius New Member

    Joined:
    Aug 1, 2021
    4
    0
    0
    Location:
    Maryland
    Vehicle:
    2008 Prius
    Model:
    Base
    About 2 days ago after when I left for work I noticed that the clock was back to 1:00 and my radio station presets were reset. Thinking nothing of it I set the clock fixed the stations and went on about my day. when I got off and made the long drive back home I noticed that it had done it again. The next day I went to run some errands and it started fine but when I got to the store I shut the car off and walked away hitting my key fob to lock the car nothing happen. I got back in and notice the lights were on on the dash, I though maybe I forgot to turn it off (that has happen before). I put my foot on the break and turned it off. This morning my mother needs to use the car to go to church it started fine and she went about her day. She just called from the church a few mins ago saying the doors wouldnt lock and the car will not turn AT ALL.

    is this the 12v or the cells under the hood (sorry I dont know what they are called)
     
    #1 OldlinePrius, Aug 1, 2021
  2. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,798
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Yes, that.
    But it might also be a bad connection on one of the main 12 V cables......at either end.
     
    #2 sam spade 2, Aug 1, 2021
  3. Another

    Another Senior Member

    Joined:
    Jun 22, 2021
    1,817
    515
    0
    Location:
    Naples, Florida
    Vehicle:
    2007 Prius
    Model:
    Touring
    How old is the 12v battery?
     
    #3 Another, Aug 2, 2021
    SFO likes this.
  4. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,517
    14,135
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Welcome. It sounds like it might be a bad ground connection where the 12V connects to the body under the floor in the hatch area on the right side of the car. Also, the connections at the battery terminals can come loose. Or, the 12V battery might just be very low. You should check the voltage both at the battery terminals and also at the jump point under the hood to make sure they are close to the same. Both should be over 12V. If the battery tests good but the jump point is low, then it's a loose connection. My money's on the loose connection. If the battery was so low you lost your radio presets, I don't think you'd be able to start the car.

    By cells under the hood, do you mean the traction battery? That's not under the hood. That's in the rear under the deck. When the car is off, it is completely disconnected by a relay. Pressing the start button with your foot on the brake closes the relay and at that point, the traction battery more or less takes over.

    As for putting your foot on the brake to stop the car, I can't figure out why people do that. As with almost all cars, you need your foot on the brake to start it, not to shut it off.
     
    #4 jerrymildred, Aug 2, 2021
  5. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,798
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    It might be because if you do not put your foot on the brake to stop, you likely will run into the car ahead.
    :ROFLMAO:
     
    #5 sam spade 2, Aug 2, 2021
    Another likes this.
(You must log in or sign up to post here.)