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

12 V Battery Help

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Moonpie30, Aug 14, 2020.

  1. Moonpie30

    Moonpie30 New Member

    Joined:
    Aug 14, 2020
    6
    1
    0
    Location:
    Biloxi
    Vehicle:
    2008 Prius
    Model:
    N/A
    A few days ago, my car kept saying the trunk was open even though it wasn't. This drained the battery and I had it jump started from the front. I fixed the light staying on by using W240 on the latch. I drove a pretty good distance that day and the next. As I was driving home, I got the red triangle, the car cut off mid drive but I was able to pull over. It restarted, drove a few blocks and quit again. Restarted drove about a mile, then quit and could not restart. I could tell the battery was dead because the lights wouldn't come on, etc. I had to have it towed home.
    When I examined the 12 V battery, I noticed it had a sprinkle of beach sand on top and that the left terminal was somewhat corroded. I removed it and cleaned the terminals. I let it sit overnight and tested it with a multimeter and it was 12.58.
    I haven't tried to charge it with a charger since I don't have one. I thought maybe if I could turn the car on it would recharge the battery?
    Anyway, I was reconnecting in proper order, positive first, but each time I try to put on the negative cable it sparks. I'm pretty sure that's not supposed to happen. I checked the wire all the way where it conects to the car body and didn't see any flaws in it.
    Any ideas what I"m missing?
     
    #1 Moonpie30, Aug 14, 2020
  2. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,525
    3,781
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Sparking means you are acting too gingerly. There is enough current draw to cause some minor sparking, so just get that clamp on the post in one quick forceful movement. Make sure to open up the clamp fully beforehand and then make sure both the positive and negative are tightly done up, with the clamp sitting all the way down to the bottom of the post.
     
    #2 dolj, Aug 15, 2020
    Last edited: Aug 15, 2020
    Mendel Leisk and Moonpie30 like this.
  3. Moonpie30

    Moonpie30 New Member

    Joined:
    Aug 14, 2020
    6
    1
    0
    Location:
    Biloxi
    Vehicle:
    2008 Prius
    Model:
    N/A
    I'm wondering what could have caused it to quit while I was driving. The tow truck guy checked the voltages and said it wasn't the alternator.
     
    #3 Moonpie30, Aug 15, 2020
  4. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,835
    38,324
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    "Tightly" as in one-handed turning of the bolt on the clamp with a small box wrench. Snug it down, then a bit more tightening effort: firm but not extreme. Pull gently on the cable, make sure it's in no way loose.

    Repair Manual says 53 inch/pounds, roughly 4.5 foot/pounds, a quite low value.
     
    #4 Mendel Leisk, Aug 15, 2020
    Last edited: Aug 15, 2020
    Moonpie30 likes this.
  5. Moonpie30

    Moonpie30 New Member

    Joined:
    Aug 14, 2020
    6
    1
    0
    Location:
    Biloxi
    Vehicle:
    2008 Prius
    Model:
    N/A
    I guess I'm confused because I read several threads that said there should NEVER be a spark, if everything is turned off, which it is, there should be no sparking. The negative cable is attached at the car body. I am trying to reconnect the part that goes on the terminal.
    So why is there a spark if everything is off?
     
    #5 Moonpie30, Aug 15, 2020
  6. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,835
    38,324
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    It's normal to have a slight spark just as you make the negative connection. The car is always using a connected battery, even when off. Not heavy use, but some, to maintain memories, various detection functions and so on.
     
    #6 Mendel Leisk, Aug 15, 2020
    Moonpie30 likes this.
  7. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,109
    5,819
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    I'm glad he figured that out, because a Prius does not have an alternator......
     
    #7 TMR-JWAP, Aug 15, 2020
    Moonpie30 and Mendel Leisk like this.
  8. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,389
    15,158
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    You can't turn everything off; there is a lot of stuff in the car that is always on, dreaming of electric sheep.

    What's more, most of that stuff contains capacitors, electrical storage cans that help smooth out fluctuations in supply. If you are reconnecting the battery after it has been unhooked for a while and all those capacitors are empty at the same time, there's quite a noticeable slurp when you make that last connection.

    Anything you read saying there should never be a spark was goofy. Consider the usual advice given for jumper cables: you make three of the four connections at battery terminals, saving the last − connection for last, and you make that one to the body ground somewhere, distant from the battery. The reason for that advice has always been that a spark is expected when completing the last connection, and you'd rather not have that spark near the battery, in case the battery has been gassing off.
     
    #8 ChapmanF, Aug 15, 2020
    Moonpie30 likes this.
  9. Moonpie30

    Moonpie30 New Member

    Joined:
    Aug 14, 2020
    6
    1
    0
    Location:
    Biloxi
    Vehicle:
    2008 Prius
    Model:
    N/A
    :LOL::LOL::LOL::LOL::LOL: I'm glad I"m not the only clueless one!
     
    #9 Moonpie30, Aug 15, 2020
  10. Moonpie30

    Moonpie30 New Member

    Joined:
    Aug 14, 2020
    6
    1
    0
    Location:
    Biloxi
    Vehicle:
    2008 Prius
    Model:
    N/A
    Thanks! I feel better. Guess I would've made a terrible caveman with my fear of fire.
     
    #10 Moonpie30, Aug 15, 2020
  11. Moonpie30

    Moonpie30 New Member

    Joined:
    Aug 14, 2020
    6
    1
    0
    Location:
    Biloxi
    Vehicle:
    2008 Prius
    Model:
    N/A
    THANK YOU!
     
    #11 Moonpie30, Aug 15, 2020
    Mendel Leisk likes this.
  12. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

    Joined:
    Oct 1, 2009
    1,135
    1,560
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    N/A
    As said, you are pretty much assured of some electrical fireworks when making the negative connection.

    For some reason, it bothers me witgh the Prius becuase it occurs "inside" the hatch vs. in the engine compartment.
    kris
     
    #12 cyberpriusII, Aug 16, 2020
(You must log in or sign up to post here.)