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Water in 12V battery compartment ?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by philip hallstedt, Jan 28, 2016.

  1. philip hallstedt

    philip hallstedt New Member

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    have 2008 Prius. Found the battery compartment full of water when I went to change the battery. About 3 quarts of water. All drain holes have rubber covers so removed one to drain and let dry, but I can't find the source of the water. Looked on sides of metal body. No clues? I did have the car go through a car wash but that should not create this issue. No water on carpet. Rear door seals in great shape. Thoughts?
     
  2. Fingers04501

    Fingers04501 Junior Member

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    Did you notice any moisture around the rear taillights?
     
  3. Stevewoods

    Stevewoods Senior Member

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    Not to be unwelcoming to a new person, but this is a common problem and there are numerous posts about it. Try searching about a bit and I bet you find your answer here on PriusChat without too much effort.
     
  4. valde3

    valde3 Senior Member

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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    What fingers said. And recheck the hatch seals, more exhaustively, say hosing the hatch area with someone inside?
     
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Here is one clue: Inspect the hatch opening at the upper corner, right side, looking at the weld seam hidden by the black plastic trim that runs longitudinally along the roof. You may find very mild cracking in a weld, but that will be sufficient to leak water into the hatch which ends up in the battery well.
     
  7. philip hallstedt

    philip hallstedt New Member

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    You are not unwelcoming. I am new and appreciate the sharing of your knowledge that this is a common problem. Appreciate the insight! Now if I can check the taillight and hopefully fix it.
    merged
    Not yet. Will check again.
     
  8. edthefox5

    edthefox5 Senior Member

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    I was in an accident a few years ago and replaced the rear tailight with a non oem light assy. It leaked. I got in the car hatch area with flashlight while someone hosed the car down and quickly saw dripping out of the tail light. It's amazing how just dripping water can fill the hatch up. I gooped it up and now ok.
    But I do have a weld crack also that patrick mentions and it leaks there too but not bad.

    Be aware the plastic black strips that run down each side of the roof just pop right off. There on clips. So pull up the end at the rear hatch area of that strip and look for long crack starting at weld area or progressing to that strip area.

    Btw, if the battery well is full there's water under the spare tire too. If you garage the car you can remove the rubber plug in the battery well.
    And under the spare tire.
    If you don't I might not recommend that as many many reports of rat infestation in a Prius and a fairly big hole in the bottom of the car
    will be a lighted entrance to a rat. I garage my car but drilled a hole through the rubber plugs enough to allow water to vent out. A weep hole.
    Instead of the huge grommet hole. Has worked very well.
     
  9. ELANGO

    ELANGO Junior Member

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    Hello, I am a new person, I own Toyota Prius 2006. Sorry, I don't know how to start a new conversation as I am new to this chat. So , My 12 V battery compartment is rusted not only the holder with long screw , but even underneath, My questions is, Is there any other plates or any other holders underneath the holder as I cannot see under the battery holder as it is severely rusted. But I can see some bolts and screws. I am not able to find any pictures or Vedios of 12 V battery compartment , may be because, this is the unique one. My car has 326000 miles on it , and self maintained and runs excellent so far. If any one can help me out , I would be great. Thank You.
     
  10. edthefox5

    edthefox5 Senior Member

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    There's been a few posts here and there about severely rusted battery wells. There was one recently where it was so bad there was a big hole where the battery should be sitting. I think that poster rigged something up. I will try to find it.

    Its rusted out because the car is leaking alot of water usually from the cracks in the hatch valley area that we are talking about in this thread.
    Fills the battery well full of water and rusts it out and under the spare tire area.

    Since not exactly sure how bad the rust is take out the 12 volt battery and post some good photos of the well area. Take out the rubber grommet too. If its really bad the battery may fall through the floor. Take the battery out and see how bad it is before the battery fall's out.
    If it does and shorts out the 12 volt buss you will be in for alot of $$$$$ to fix that.

    With that kind of miles I suspect the under side of the car is rusted ATH too. While your taking pictures take some of the front suspension too so we can see how bad it is.

    This is where having a mechanic or gas station change your oil is very beneficial because the side benefit is most will let you under the car to look around while it's up on the rack while he changes the oil. You may have to duke the guy $20 but its well worth it. I do that regularly and have taken lots of pictures of the chassis's on my cars. I have the iPhone app the camera lighted magnifier and that is awesome.

    I would imagine most people have never seen the underside of there car. Its pretty informative. But I guess ignorance is bliss.
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    Moral of the story: pull everything out, say at least once a year. Good excuse would be to check the pressure on the spare tire.
     
  12. dannybjax

    dannybjax Junior Member

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    This happened with my son's 2006 and we took everything out, sealed with silicon then sprayed Flex Seal in there too! Also sealed the right side rear hatch channel with silicon in strategic spots as well. Lost the rubber drain plug seal in the process. Does anyone know the Toyota part number? Cannot seem to find it and not sure what it would be called.
     
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  13. PriusDadNoob

    PriusDadNoob Junior Member

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    Dude! I dried my battery compartment and after one rainy day had a liter of water in there!!!!
     
  14. mr_guy_mann

    mr_guy_mann Senior Member

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    Did you look for and seal any body cracks around the hatch opening? (Near the T/G lift cylinder mount and goes further up under the black cover for the drip channel). Also can have leaks around the tail light where it mounts to the body.

    Posted via the PriusChat mobile app.
     
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  15. Prius Ted

    Prius Ted New Member

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    I also have this problem that I just noticed while changing the battery. No water anywhere else but the battery well. Is there any reason why I shouldn't just remove the drain plug permanently in that well (the one under the battery)? Seems like minimal water can get in from underneath, and if it did, it would just drain out. The car is old, and no rust is noted - I have learned in my day that trying to plug leaks sometimes diverts water elsewhere.
     
  16. edthefox5

    edthefox5 Senior Member

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    Only one reason and that's if the car lives outside it will get meese infested with those plugs removed. Mice find the wiring on a prius delicious and have damaged many a G2 on this site. I see a G5 with $17,000 worth of mice damage on that forum right now.

    Just drill a small weep hole in that rubber plug and the one under the spare tire too.

    Also be aware the place that water is dripping from the hatch corner drops water right on top of the hybrid battery fan power connector and will rot it out.
     
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  17. Prius Ted

    Prius Ted New Member

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    ****Great advice. I will spend some time to try to clean and solve the leak and put a weep hole in the plug just in case I don't fully solve the problem. Fortunately, my spare tire well is dry as a bone. Then I will ignore it until I can't ignore it anymore :). Thank you. Ted.
     
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  18. edthefox5

    edthefox5 Senior Member

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