12v Power from cabin.

Discussion in 'Gen 3 Prius Main Forum' started by MHLikhon, Nov 24, 2018.

  1. MHLikhon

    MHLikhon Junior Member

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    Hi I am looking for a 12v live wire/fuse from 2010 Prius cabin which will give power after I turn off the car or lock the car and will cut the power when I unlock the car.
    Thank You.

    Posted via the PriusChat mobile app.
     
  2. bisco

    bisco cookie crumbler

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    careful, the 12v is very small and weak
     
  3. MHLikhon

    MHLikhon Junior Member

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    Thanks,
    But can you please tell which wire or fuse gives power after locking or turning off the car but won't give power after I unlock or start the car?

    Posted via the PriusChat mobile app.
     
  4. tvpierce

    tvpierce Senior Member

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    I don't believe such a circuit exists in the Prius -- or any car for that matter. It's not that it would be difficult to do, just that I can't think of any application where a manufacturer would need it.
    You could make one by using a standard relay you could find at any auto parts store. You would just wire it to open when power is present, and close when no power is present. That would require that you locate or create an unswitched power supply (fused directly to the battery) for the load, then use a switched power supply (like that which feeds the cigarette lighter socket) as the "signal" to control the function of the relay.
    As @bisco pointed out, the Prius battery is pretty small compared to a conventional car battery, so you'd want to be conservative with the load you put on it while the car is not powered on.
    I'm curious, what's your intended use for this circuit?
     
  5. Johnny Cakes

    Johnny Cakes Active Member

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    tvpierce hit it square on. If you don't solder, there are off the shelf relay kits where you can just connect the wires to the constant power and trigger terminals.

    But definitely heed what bout bisco and tvpierce said -- its not that the Prius battery is on the smaller side compared to ICE cars. It is that the Prius battery incredibly small. While an oversimplification, the Prius battery is just there to run the "start up" electronics, and then everything gets its power from a DC to DC inverter connected to the traction battery. So you can deplete the 12 battery very quickly, which is bad news.

    I'm curious also -- sounds like maybe you have an interesting use for this circuit.
     
  6. Grit

    Grit Senior Member

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    If there’s no stopping this person, we ll be here to teach them how to jump start and save up for battery replacement.
     
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  7. Johnny Cakes

    Johnny Cakes Active Member

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    Relays Timers and Programmable Modules
     
  8. tvpierce

    tvpierce Senior Member

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  9. Johnny Cakes

    Johnny Cakes Active Member

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    Absolutely agree. I was following up on the thought in my original post "if you don't solder..." While overkill, the OTC boards have screw terminals.
     
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  10. tvpierce

    tvpierce Senior Member

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    Good point.
     
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