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Just disregard the dash if you think the 12-volt battery is low?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Chuck., Nov 28, 2016.

  1. Chuck.

    Chuck. Former Honda Enzyte Driver

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    Tonight I drained my 12-volt battery using my portable tire pump. Got the red triangle of death, messages about my transmission. I jumped it with another car, but had to drive a few hundred yards to clear the red triangle of death and such. This also happened on my Honda Insight. My hunch is if the voltage is under 10 or so, you just can't trust the dash. Posting to see if this is common and the way to move on.

    P.S. Different issue that caused the battery drain. Is there ANY WAY to use the 12-volt jacks without powering up the car?
     
  2. daveatm14

    daveatm14 Junior Member

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    You need the mod to make your 12V socket hot when the key is off. I used the kit so I can charge phone when car is off.
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Get a 120 volt to 12 volt converter, use that at home.

    My solution is to use a decent sized floor-standing hand pump. I guess designed for bicycles, soccer balls and the like, but they're fine for car tires too, just a bit of a workout. I've even used them after totally flat plug-repaired cases.
     
    #3 Mendel Leisk, Nov 28, 2016
    Last edited: Nov 28, 2016
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  4. andrewclaus

    andrewclaus Active Member

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    Ditto the above alternatives. But if you have to use a heavy load on the 12V, another solution would be to use the car in IG-ON or Ready mode. Then you'll have the hybrid system behind your tool. In IG-ON, you'll have the HV battery and 12V converter connected, and in Ready you'll have a tank of gasoline ready to work for you, too.

    I would not disregard warning lights ever, or assume the cause. But replacing the 12V sometimes solves many apparently unrelated problems, if that was the question, and checking the battery is often the first action recommended here.
     
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  5. bisco

    bisco cookie crumbler

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    there's a great old thread, 'prius acting funny? check the 12v'. or something to that effect. still applies.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, I'd second what @andrewclaus says: just have the car "running" when using pretty much any load, I'd say even the radio, and you won't run into trouble with a run-down battery.
     
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  7. drysider

    drysider Active Member

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    I would suggest that modifying the 12v accessory plug to be live when the car is off is asking for a dead battery. It doesn't take much current draw to drain the battery.
     
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  8. Paul Schenck

    Paul Schenck Active Member

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    Chuck; To you question about the Dash Red Triangle it takes a driving cycle to clear it, or a code reader. To your second question, I added a 12Volt inverter at the Battery, I keep it connected and leave it under the cover in back. I also connected a 12v plug to it as the contacts were convenient for pumps etc.
    Lastly I usually have the car on when I use the inverter or the pump so I keep the 12 volt charged with the hybrid system. Why not??


    iPhone ?