1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Electrical system and mpg

Discussion in 'Prius c Audio and Electronics' started by TwoTime, Apr 2, 2015.

  1. TwoTime

    TwoTime New Member

    Joined:
    Apr 2, 2015
    3
    0
    0
    Location:
    Raleigh, NC
    Vehicle:
    2015 Prius c
    Model:
    One
    Just picked up a new 2015 Prius c One, looking at upgrading the audio. I am concerned about the hybrid system and how it would interact with a mid power aftermarket stereo. Thanks in advance for any insight :)

    I am looking at installing:

    Alpine MRV-F300 50 watts x 4
    Alpine MRP-M500 500 watts x 1

    Would the 700 watt draw cause any problems for the electrical system? Doing a bit of reading on these forums seems to indicate the car can handle up to 100 amps, and the 700 watts would be more like 60 amps. So it should be ok, right? Are there any other considerations to take into account? I certainly don't want to mess anything up. A local installer I have been talking to seems to think it might be too much for the cars stock systems.

    The other question is for people that have similar powered systems installed, did it effect your gas mileage in any meaningful way? I would imagine it would be minimal but I am curious to others experiences.

    Thanks for the help, this site seems to be a great resource, I look forward to contributing.
     
    #1 TwoTime, Apr 2, 2015
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Remember one horsepower is about 746 watts. That's about what you'd lose if your stereo consumed 700 watts constantly, but of course it doesn't, those should be only the rare instantaneous musical peaks.

    The DC/DC converter total capacity may be about 100 amps, but that also includes the parts of the car that you already have. How much is left for you depends on whether it's day or night (headlights etc.), warm or cold (rear defog, PTC heaters, etc.) and so on. The PTC heaters in my car (Gen 1) max out around 700 watts all by themselves - I don't know what the figure is for the c.

    If you look up your wiring diagram on techinfo.toyota.com you might look for one interesting signal named IDH. It exists in my Gen 1, I don't know about the c, you'd have to look it up.

    IDH is a signal from the DC/DC converter to the heater control. The converter asserts the signal when too many amps are being drawn, and it tells the heater control to shut off the PTC heaters if they are on.

    You might be wise to tap into that signal, at least with an LED that would get your attention when the converter is complaining it's overloaded. You could also design a way to have it automatically mute your stereo until the overload clears. Or have your stereo assert it, so the PTC heaters are kept off.

    I guess it wouldn't surprise me if between Gen 1 and the c, they could have changed from IDH being a simple signal on a wire, to just being some message the converter sends out on the CAN bus. Your manual would say.

    -Chap
     
    #2 ChapmanF, Apr 2, 2015
    TwoTime likes this.
  3. kingnba6

    kingnba6 Active Member

    Joined:
    Mar 17, 2013
    1,018
    242
    0
    Location:
    NY
    Vehicle:
    2013 Prius c
    Model:
    One
    Thats a lot of good information in the previous post!
     
    #3 kingnba6, Apr 2, 2015
  4. TwoTime

    TwoTime New Member

    Joined:
    Apr 2, 2015
    3
    0
    0
    Location:
    Raleigh, NC
    Vehicle:
    2015 Prius c
    Model:
    One
    Thanks for the responses :) It's been tough for me to find concrete answers on this stuff since prius c is newer and less popular than regular prius. There seems to be a wealth of info on high wattage systems in a regular Prius, and they pretty much all point to "its all good, just make sure you run it in ready mode." So maybe a good question to ask would be, are there components in the prius c hybrid system that are less robust than a regular prius that could cause issues? Or is going off prius owners experiences a good idea?
     
    #4 TwoTime, Apr 4, 2015
  5. KYBlue

    KYBlue Active Member

    Joined:
    Jun 28, 2013
    227
    112
    0
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    One amp is fused at 40amps the other at 2x30 (60). They are typically on the high end for fuses, and one appears to be class D and the other Class T (or similar tech). I'm guessing at the volumes you'll be comfortable listening you'll be drawing well below 40 amps total. I think you are good. Spend the money for good and proper sized electrical wiring and distribution blocks/fuses or circuit breakers. This will protect your car and your amps.

    Do some research but the new power supplies in amps (class D, class T) are way better than the old school stuff (google PPI A1200.2, I had two of those pupies in my car (with upgraded battery and alternator) back in the day lol....

    Chris
     
    #5 KYBlue, Apr 5, 2015
  6. TwoTime

    TwoTime New Member

    Joined:
    Apr 2, 2015
    3
    0
    0
    Location:
    Raleigh, NC
    Vehicle:
    2015 Prius c
    Model:
    One
    Funny you mention the PPI amps, it was my buddy running 2 of those or similar on 4 PPI flat 12" (in an eclipse lol) that got me into car audio in the first place.
     
    #6 TwoTime, Apr 7, 2015
(You must log in or sign up to post here.)