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2010 Prius not turning on :(

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by egatehpro, Oct 1, 2021.

  1. egatehpro

    egatehpro New Member

    Joined:
    Oct 1, 2021
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    Location:
    Louisiana, US
    Vehicle:
    2010 Prius
    Model:
    N/A
    Yesterday I noticed my Prius' air system was off when I turned on the car. Seemed strange, but I let it slide. Then, I turned off my car & it immediately popped right back on. So I knew something was off. I was also really low on gas, so I figured I'd get gas first and see if anything changed. I filled my tank and didn't have any more problems all night. I woke up today, and my car won't turn on.

    Any suggestions on what could be the problem?

    I just got a new 12v battery a month and a half ago so I don't think that's the issue? However I just checked and did notice there is some water in the 12v compartment. I had noticed this previously on my last battery when it stopped working, and tried to seal the entrance spots - it worked for a few weeks, but I guess it didn't stand the test of time. Any help is much appreciated.
     
    bisco likes this.
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    welcome!
    if you are going to try to diagnose/repair yourself, you'll need some tools. start with a voltmeter, and measure the 12v at the jump point with the car off. then turn on the headlights and measure every minute for five minutes.
    the water doesn't affect the battery, all the connections are on top. are they clean and tight? especially negative to ground?
    how many miles on her?
     
  3. egatehpro

    egatehpro New Member

    Joined:
    Oct 1, 2021
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    Location:
    Louisiana, US
    Vehicle:
    2010 Prius
    Model:
    N/A
    175k on her
     
    bisco likes this.
  4. pairoPriuii

    pairoPriuii Junior Member

    Joined:
    Mar 2, 2021
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    Location:
    lower Alabama
    Vehicle:
    2010 Prius
    Model:
    III
    In case you didn't know, the 12-volt battery does not actually start the Internal Combustion Engine (ICE), it only powers up relays that, in turn enable the High Voltage (HV) battery to start the ICE when the HV battery requires charging. So as long as the 12-volt battery is somewhere close to 12 volts, it will do it's job. The problem arises when the HV battery doesn't have enough voltage to do it's job because there is no way to jump it off or roll start the car. When this happens, your friendly local Toyota dealer will tell you the only solution is a new HV battery, to the tune of about $4k, installed. There are, however, a handful of aftermarket retailers offering various "refurbished" batteries in the range of $1-2k, with a range of warranties. Or you can roll the dice and buy a HV battery grid charger ($300ish) which trickle charges the HV battery over the course of 24 or so hours. The question then becomes why the HV battery was allowed to become so discharged in the first place...
     
  5. egatehpro

    egatehpro New Member

    Joined:
    Oct 1, 2021
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    Location:
    Louisiana, US
    Vehicle:
    2010 Prius
    Model:
    N/A
    Thanks for the post. I took my 12v to the Toyota dealership today and it's unfortunately nowhere near the correct voltage. I just got it a month and a half ago. Just a faulty battery or is there anything else I should be concerned with & need to check/replace? I have been getting some water in the 12v compartment. I'm not sure if it's enough to damage the battery though.