What color for power?

Discussion in 'Gen 2 Prius Audio and Electronics' started by Wouter73, Oct 17, 2021.

  1. Wouter73

    Wouter73 Junior Member

    Joined:
    Jan 1, 2018
    14
    0
    0
    Location:
    Netherlands
    Vehicle:
    2007 Prius
    Model:
    II
    I would like to hook up a usb charger in the back of the prius. To which color(s) do l hook it up for power? The charger comes with a black and red wire. Tia for any advice IMG20211017123600.jpg IMG20211017123950.jpg

    Verstuurd vanaf mijn CPH1951 met Tapatalk
     
  2. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    5,745
    2,283
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    I think it is likely that there are NO "hot" wires in that bundle at all.
    You need a wire that has voltage on it all the time that the vehicle is "ready" (running) but not hot when the vehicle is OFF.
     
    Wouter73 likes this.
  3. Wouter73

    Wouter73 Junior Member

    Joined:
    Jan 1, 2018
    14
    0
    0
    Location:
    Netherlands
    Vehicle:
    2007 Prius
    Model:
    II
    Good point
    So l'll probably have to start thinking about a more suitable spot for a charger in the back

    Verstuurd vanaf mijn CPH1951 met Tapatalk
     
  4. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    5,745
    2,283
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Not necessarily.
    You need to start thinking about longer wires to connect it to where there is suitable power.
     
    Wouter73 likes this.
  5. koco

    koco Member

    Joined:
    Oct 4, 2021
    104
    32
    0
    Location:
    Las Vegas
    Vehicle:
    2005 Prius
    Model:
    Base
    Maybe tap into the existing power port wires. They are 15 amp circuits.
     
  6. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    5,745
    2,283
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Yes, that's what I was trying to say. :)
     
  7. koco

    koco Member

    Joined:
    Oct 4, 2021
    104
    32
    0
    Location:
    Las Vegas
    Vehicle:
    2005 Prius
    Model:
    Base
    You can find a decent place to tap in if you take a look at what is available. Just don't use any circuits that are used for onboard computers, airbags, brakes etc. and avoid low powered circuits. If I was to put one in the very back of the car I would just attach directly to the battery with a fuse, but it would stay on all the time. A relay would be needed to make it switch off with the ignition.
     
  8. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    5,745
    2,283
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    IF.....you are going to go to all of the trouble to find "switched" power to trigger a relay, you probably could just use THAT source to actually power the USB device. They don't take much power. :)
     
  9. alftoy

    alftoy Active Member

    Joined:
    Mar 16, 2009
    302
    126
    0
    Location:
    Saskatchewan, Canada
    Vehicle:
    2008 Prius
    Model:
    Premium
    #9 alftoy, Oct 19, 2021
    Last edited: Oct 19, 2021
  10. Wouter73

    Wouter73 Junior Member

    Joined:
    Jan 1, 2018
    14
    0
    0
    Location:
    Netherlands
    Vehicle:
    2007 Prius
    Model:
    II
    Thanks for the replies, appreciated!

    Verstuurd vanaf mijn CPH1951 met Tapatalk
     
  11. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    14,619
    10,273
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    If it's a recent USB device conforming to the USB Power Delivery specification, a separately fused circuit and a relay would not necessarily be overkill.
     
  12. koco

    koco Member

    Joined:
    Oct 4, 2021
    104
    32
    0
    Location:
    Las Vegas
    Vehicle:
    2005 Prius
    Model:
    Base
    The purpose of a relay for this application would be to switch the power port off when the car is turned off so as not to drain the aux battery. Also, the relay would allow for the additional power port to be connected to the aux battery so as not to place a relatively large current draw on some random nearby circuit that is not designed to sustain an additional draw.
     
  13. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    5,745
    2,283
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Do you really NOT understand that in order to do that, you must find an electrical circuit/wire that goes off when the car is turned OFF to trigger the relay ?

    AND....he is not installing a "power port" but a USB charging port which does NOT have a "relatively large current draw".

    IF he was installing a multi-purpose cigarette lighter style port, the answer would be entirely different.
     
  14. koco

    koco Member

    Joined:
    Oct 4, 2021
    104
    32
    0
    Location:
    Las Vegas
    Vehicle:
    2005 Prius
    Model:
    Base
    I really do understand how relays work. The triggering of a relay is accomplished with a low amperage; that's one reason they are used instead of running heavy guage wires for long distances...understand? Are you suggesting it is better to randomly tap into some nearby circuit and hope for the best?
    A USB port can draw up to 5 or 6 amps, and that's quite a bit to add onto some of the circuits. Look up Quick Charge USB port; these days many phones require it.
     
  15. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    5,745
    2,283
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Sorry. It didn't sound like it.
    And you are right about the best way to do it.
    That would be either "activating" a spare switched and fused circuit or using a relay.
     
Loading...