1. Attachments are working again! Check out this thread for more details and to report any other bugs.

12 volt battery fiasco

Discussion in 'Gen 2 Prius Technical Discussion' started by mke039, Mar 21, 2008.

  1. mke039

    mke039 Junior Member

    Joined:
    Mar 21, 2008
    11
    0
    0
    Location:
    Massachusetts
    Vehicle:
    2006 Prius
    "Borrowed" my wifes 2006 Prius and didn't shut it down properly. The next morning it was dead, would not light up or start.

    Toyota service said to tow it in...this insulted my "fix it yourself or pay through the nose" mentality.

    So I decided to take a stab at it myself.

    First off, the battery is in the trunk, and of course the trunk would not open with no power. So I saw in the manual that you can release the trunk from the inside. First you must remove the mat, the cover and then the whole black plastic basin that is above the spare tire.

    That done I found the manual release lever on the inside and popped the trunk.

    Then I removed the battery cover to get to the battery on the right side of the trunk.

    There is a plastic guard over the positive terminal that is all but impossible to remove, so I bent it up to get to the terminal.

    Then I connected my car battery charger and instantly the car lighted up. I went up front and shut down the power (this time correctly).

    I waited about an hour for the little pathetic battery to charge, and started up the car.

    Although it seemed fine, drove fine ect. I still took it down to the service dept. They said that they put a "load test" on the batt and recommended that I replace it for $170. I did....it is my wifes car after all.

    The moral to this story is to NEVER shut the car down while standing outside and reaching in. Sit in the seat with your foot on the brake after putting it in park!

    Or pay at least $170 for your error.
     
  2. diamondlarry

    diamondlarry EPA MPG #'s killer

    Joined:
    May 20, 2007
    559
    12
    0
    Location:
    Elkhart, IN
    Vehicle:
    2007 Prius
    I almost hate to bring it up but, the manual also tells how you can lift the hood and use the terminals to jump the car instead of going through the ordeal of crawling through the hatch.:redface:
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,482
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Yes, the red plastic guard is difficult to remove so you did the right thing by bending it to access the positive terminal.

    If you still have the old pathetic battery it might be interesting to fully charge it, then discharge it with a load (for example, a few 12V landscape lights) and see how long the battery will power the load. That will show you the effective AH capacity of the battery (when new, the capacity is in the low 30's). If it is still good you might decide to keep it as a spare or for other emergency purposes.
     
  4. prius729

    prius729 New Member

    Joined:
    Nov 17, 2007
    120
    1
    0
    Location:
    Hobbs, NM
    Vehicle:
    2008 Prius
    so, if I were to shut it down just by pressing the power button without my foot on the brake, while still inside the car, then the car is in fact not powered down fully?

    I'm asking because I have done this a few times and I haven't had a dead battery problem yet, even overnight.
     
  5. diamondlarry

    diamondlarry EPA MPG #'s killer

    Joined:
    May 20, 2007
    559
    12
    0
    Location:
    Elkhart, IN
    Vehicle:
    2007 Prius
    I don't think you need to have your foot on the brake to power off.
     
  6. prius729

    prius729 New Member

    Joined:
    Nov 17, 2007
    120
    1
    0
    Location:
    Hobbs, NM
    Vehicle:
    2008 Prius
    I guess what mke039 did wrong was standing outside the car when powering down then?

    I'm gonna have to test this out later...
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,482
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The OP probably pressed the POWER button twice or thrice, cycling from READY to IG-OFF then to ACC-ON, or maybe even IG-ON. If the car is left in ACC-ON or IG-ON, the battery would discharge over time.
     
  8. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,041
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    I'd bet a dime that's what he did. It's harder to see whether the dash lights go out as they should when you're standing outside the car. Why didn't he shut it OFF before getting out?