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12 volt battery change and alot of water under it

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by khp, Feb 5, 2013.

  1. khp

    khp Member

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    Well I have been watching my 12 volt battery voltages in the morning before I start my 2006 Prius and I have been noticing the voltage is getting lower ( 11.6) a couple of times. So I decided to replace the 12 Volt battery with a Optima Yellow Top DS46B24R that I purchased from my Local NAPA.
    NAPA's Part number for this battery is N9951HEV. Manufactured 1/13 and 12.8 volts. Install went fine and all is well.

    But I noticed a lot of water in the cavity under the aux battery. I went through the carwash last week and I suspect the water is getting in through the HV battery air vent to the outside. This is making me very nervous. Any other car I would leave the little rubber plug out of the well under the battery and let it drain out all the time. I am little more cautious of doing this with all the electronics in that area of the Prius.

    Anyone else ran into this? Probably should stay away from the under car washes from now on.
     
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  2. edthefox5

    edthefox5 Senior Member

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    No undercar car washes for Prius.
     
  3. jetsfan_00

    jetsfan_00 Junior Member

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    I have 2005 with 190000 miles.
    I replaced this battery at 6 years and had water in the compartment. I replaced the tailgate gasket to correct the leak.
     
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  4. khp

    khp Member

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    I didn't see any water other than the water under the battery area. It doesn't look like the door seal is leaking. I may just remove the spare tire cover pan and sit in the rear area and run the car through the car wash and confirm where the water is coming from.
     
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  5. bisco

    bisco cookie crumbler

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    i think i recall a thread about water leaking through a seam in the sheet metal fender.
     
  6. edthefox5

    edthefox5 Senior Member

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    Most leaks have been traced to a crack in the seam up by the hatch door hinges. Where the quarter panel is welded to the roof. Right by the hinge mounts.
    Noticeable crack in the paint in the valley. Probably from constant slamming of the hatch.

    Water leaks in there and runs down inside of car into tire storage area. Usually rust under spare tire and wet under battery.
     
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  7. khp

    khp Member

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    OK I didn't go through the car wash since I dried out the water under the aux battery and I looked tonight and there was some more water under the aux battery. I removed the aux battery and dried the area under the battery again and looked at the seams around that area and noticed one area that was not gooped up with the sealant they use. I used some silcone sealant around the suspect area and assembled everything again. I will check it again this weekend. Looks like more rain in the forecast so I can test it. The door seal looks fine. I'll post my findings this weekend if I remember.
     
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  8. khp

    khp Member

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    Well the hunt for the source of the water below the 12 volt battery was interesting to say the least. All I can say is you better have real good eyes or in my case a magnifying glass. I really didn't have much chance to look for the water source this weekend on my 2006 .

    My daughters 2004 Prius 12 volt battery was failing so I had her bring it down and I was shocked to find her car had about 2-3 inches of water under her 12 volt battery. I drained it, replaced the battery and bunch of other items.

    After searching all the same water issues everyone is having here my son and I did the garden hose on the outside and me on the inside. Leaking like sieve inside between two pieces sheet metal above the battery area. I followed all the advice from everyone else s water source hunt. Checked the hatch seal, removed gas strut on that side, looked at all the seams on the hatch channel and all looked good.

    After finding a message here about small cracks under the trim stripe on the sides of the roof I revisited looking at that area my her 2004 ( with a good light and magnifying glass this time) and low and behold a small crack right below the small clip that holds on the trim piece. Well I used some clear silicone on hers and looked at my 2006. Same thing.... So I hope that does it but I am sure it will. So if you are still looking for the source of the leak on your car really clean this area and good with a magnifying glass and good light. I missed this the first time.
     
  9. JMD

    JMD 2012 Prius 4 Solar Roof

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    Well said KHP !
     
  10. edthefox5

    edthefox5 Senior Member

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  11. khp

    khp Member

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    I wonder if you can buy that in a smaller can? Quart would be over kill for what I need.
     
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  12. GasSippr

    GasSippr Junior Member

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    I'm having the same problem. Has this proved to be the source of the leak? Can you post pictures? Thanks!
     
  13. khp

    khp Member

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    [​IMG]
    2006 Prius crack right rear corner
     
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  14. khp

    khp Member

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    [​IMG]
    2004 Prius right rear corner
     
  15. khp

    khp Member

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    Neither has leaked yet....after I used some clear silicone. The silicone probably won't last but time will tell.
     
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  16. GasSippr

    GasSippr Junior Member

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    Thanks for posting those pictures I really appreciate it. Can you post pictures a little farther out so I can see where these cracks are located in relation to the rest of the car? I don't know what a trim stripe is for example so I'm not sure where to look. Thanks!!!
     
  17. khp

    khp Member

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    If you look at your car roof there are black plastic strips one on each side. Pop the rear part of the strip off at the rear of the car.( it pops straight up very easy) then clean the area around the little metal clip very good. I used 409 cleaner and a old toothbrush. The 409 cleaner was only used because it was handy. Then I used compressed air to blow the area off. If you don't have compressed air use water in a spray bottle and let it dry. Look very close because I missed the crack the first time.
     
  18. akleban

    akleban New Member

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    khp, thanks for your investigation etc…, I'm curious , now over 4 months later how your patch held up? I just replaced one of my 2005 prius's batteries today with a "Optima (8171-767) DS46B24R Yellow Top Prius Battery" (deep cycle) that I got for $150 through StreetSideAuto (free shipping, was here in 3 days!). Its a great battery, fit perfectly, but I also found water in the batteries well. All else was dry. Because the original battery was completely dead and would not even hold a charge after jumping it a few times, I had to leave a floor mat in the way of the back hatch's mechanism, so that I did not have to jump the car again just to open the rear. Anyway, it had rained a fair amount before I could get to the work there and I assumed the water had leaked in because the hatch wasn't latched. The water in the well was clear and seemed fresh, but now, after reading your post, I am curious to see if there is an actual crack that might be leaking.
     
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  19. khp

    khp Member

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    My leak was the cracks I posted in the pictures and they are fine now. I just used clear silicone on the crack after I cleaned them up with an old toothbrush and compressed air. I was back in that area last spring changing another bad module in my HV battery and it was dry.
     
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  20. *Goldfinger*

    *Goldfinger* Junior Member

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    Great Post khp, I had same issue, read this and went straight to the tiny crack in just the same place, saved me so much time and effort. In fact I doubt I would have ever found it. Didn't have any clear silicon and was desperate to do something straight away, so used superglue gell to make a little 'weld effect' seam over it. I will let you know if it doesn't work.