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Liquid in 12V Battery area?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by LadyB, Jun 13, 2015.

  1. LadyB

    LadyB Junior Member

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    Hi. My 2005 Prius gave me the Red Triangle of death about a month ago... I balked at the $4,000 repair estimate for the Hybrid Battery and other "fixes" that the dealership wanted to sell me. We opted to try to repair the HyBattery ourselves. When trying to restart vehicle after it's "open heart surgery" we discovered problems with the 12 Volt battery. (My '05 had failed to start for me a couple of times in the later part of 2014, requiring jumps, so I wasn't too surprised that the charger was indicating bad battery when we tried to recharge the old 12V that had been sitting for a few weeks.) Anyway, when we went to take the old battery out, we found that in the bottom of the 12 V Battery compartment there was about 3 inches of clear liquid. I carefully removed this liquid to some jars, but do not know if it is water or something else.

    Questions: Would standing in liquid harm the 12 v battery? Where would this liquid likely have come from? Has anyone else experienced this?

    I got a replacement Yellow Top battery and hooked it up. After a jump start, thank God, the car started up and ran again without the Triangle of Death... and put a charge on the hybrid battery. Will need to do a longer test drive tomorrow. But I want to know what people think about that liquid in the battery area...
    Thanks,
    Ber

    Edited to add: Question: Would a faulty 12 volt battery have caused the hybrid battery failure codes, plus wouldn't a battery (original to my O5 with 178K miles on it) also have been flagged for replacement by the service department?
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    It is likely that the hatch area has a leak allowing water to enter. There are several posts about this. Look for a crack along the hatch opening area and under the black trim that runs along the edge of the roof line.

    The 12V battery is not harmed by standing in water. However the source of the leak needs to be identified and resolved so that the hatch floor doesn't start to corrode.

    A faulty 12V battery might have produced an erroneous indication of a traction battery failure.

    What did you do to repair the traction battery?
     
    Fern1461 likes this.
  3. 69shovlhed

    69shovlhed Surly tree hugger

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    many technicians are too lazy to check the 12v battery, and many service writers are too stupid and lazy to make sure the tech does his job and checks it.

    you will need to stay on top of your service requirements if you want to keep it in top shape, or find good shop.
     
  4. Beachbummm

    Beachbummm Senior Member

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    remove the 12 volt battery and you will find a small rubber plug in the floor push it out with a screw driver and leave it out..
    get some rubber undercoating spray from an auto parts store and spray the inside of the compartment to stop rust
    water will drain out from now on in case you cant find the source of the leak
     
  5. bisco

    bisco cookie crumbler

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    why did you need a jump start after installing the new battery?
     
  6. LadyB

    LadyB Junior Member

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    We are not experts on this. But this is what happened...

    My Hybrid Battery was totally depleted. The 12V battery was fully charged, and the screen and dash were lit and working, but the car still would not start.

    I thought he was crazy, but my son reminded me that the 12 Volt battery only supplies power to the computer systems and accessories, leaving the job of starting the gasoline engine to the hybrid battery. He explained that the reason Toyota probably hid the 12V away in the back was that it was not the only thing that could run out of juice. The jump terminal under the hood is, it turns out, also hooked up directly to the electric starter motor, which then lets the car use its otherwise un-startable gasoline engine to recharge the hybrid battery.
    At least that's what we figured was going on. So when we jumped the car, the engine started and the problem codes (which we had cleared) stayed off.

    I've now put about 23 miles on the car and she seems to be doing well. Outside temps were around 90'F here today.

    Patrick Wong... We did, what I told myself was just probably going to be a preliminary fix... The codes that the computer threw indicated that Cell 1 was bad. I bought 2 replacement cells on ebay for about $27 each. When we were ready to "operate" we tested voltage of the replacement cells, and all the cells in the rack. The second cell from the "easy end" was the one that was low... measuring about 6.4V. They were also load tested with two 10 ohm 4 amp resistors in parallel. The bad cell started at 6.4 and dropped into the 4s under load. We did not go through a "balancing" process... (though I expect that from what I have read this will probably be required in the not so distant future... unless the big issue was the 12V battery.) Our "fix" was really much easier than others I have read about... we wanted to disrupt the least amount possible. The top bars were loosened and the white end-cap unbolted and popped off for us to slip the old out and new cell in... and then we just put it all back together. When it was reassembled, that's when we discovered that the 12V battery was dead, so I went on line and searched and fount the Optima Yellow Top... ordered online through Advance Auto Parts who were willing to do a price match on a lower price than their regular price... and I picked it up locally. (Around $160 plus a $20 core charge.)

    I figure in a few days, we will reassemble the back of my car, if all is still good.
     
  7. LadyB

    LadyB Junior Member

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    This is good advice.... we will look for that plug before we put the back of my car back together! Thanks.
     
  8. bisco

    bisco cookie crumbler

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    oh boy.
     
  9. Beachbummm

    Beachbummm Senior Member

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    pretty sure its to the front of the battery on the right side...its been a while since I had to replace a battery
     
  10. LadyB

    LadyB Junior Member

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    Just a quick update... I am up to 607 miles on our repair job of the HV battery, and plan on reassembling the back of the car!
     
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  11. LadyB

    LadyB Junior Member

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    Just thought I'd pop back in with an updated. It is now September, the car sailed beautifully through the Summer and has gone about 3,450 miles since my son and I did our repair job! I do not plan to ever go back to the dealership where they told me I needed $4,000 worth of repairs on my '05
     
  12. LadyB

    LadyB Junior Member

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    Hi Everyone! LadyB here. I always wondered when I was reading traction battery fix stories how long the fixes last.

    I just wanted to pop back on the forum to let you all know that since my June 2015 fix, my '05 Prius is still chugging along on our battery revival! Also, probably more impressively, we've logged an additional 20,000 miles since that day when the nasty prius man told me my baby would only be worth $200-300 as a trade in, and would require $4000 plus in repairs. Since then I have gotten a couple of oil changes, and I needed some new front brakes to pass my state inspection, but other than that, none of the repairs my Prius shop told me I "needed" were done and we are still, thankfully, sailing along!
     
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  13. bisco

    bisco cookie crumbler

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    congrats! thanks for the update.(y)