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

Power per bar on MFD

Discussion in 'Gen 2 Prius Technical Discussion' started by Whiteyprius, Aug 21, 2008.

  1. Whiteyprius

    Whiteyprius Active Member

    Joined:
    Feb 24, 2008
    389
    105
    0
    Location:
    North Carolina, USA
    Vehicle:
    2017 Prius
    Model:
    Two
    In western NC I often max out the battery power indicator bars. I am aware that no bars does not indicate no power, nor does all bars lit necessarily indicate 100% power. But can anyone tell me approximately how many watts each bar represents? Thanks:)
     
    #1 Whiteyprius, Aug 21, 2008
  2. direstraits71

    direstraits71 Member

    Joined:
    Jul 17, 2008
    367
    65
    0
    Location:
    Central Coast California
    Vehicle:
    2008 Prius
    #2 direstraits71, Aug 22, 2008
  3. patsparks

    patsparks An Aussie perspective

    Joined:
    Jul 12, 2007
    10,664
    567
    0
    Location:
    Adelaide South Australia
    Vehicle:
    2004 Prius
    Model:
    N/A
    Some?

    Some electricity.
     
    #3 patsparks, Aug 22, 2008
  4. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,873
    1,871
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    Your traction battery is normally maintained between 40 and 80% of its capacity (That's why it will "last the life of the car"). This shows on your power indicator as from empty to full. Since the capacity is 200 volts times 6.5 amp hours or 1.3 kwatt-hours, each bar is approximately 50 watt-hours (or one little green car). Note that the bars are not all equal value so this is an approximate calculation.

    JeffD
     
    #4 jdenenberg, Aug 22, 2008
  5. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
    2,817
    187
    49
    Location:
    Chesterfield, VA
    Vehicle:
    2005 Prius
    The link provided by DireStraits might eventually end up at with this, but to demonstrate this point:

    [​IMG]

    It doesn't address Whitey's question directly, but it does show the non-linearity of the bars.
     
    #5 JimboK, Aug 22, 2008
  6. archae86

    archae86 Member

    Joined:
    Jun 19, 2008
    153
    24
    0
    Location:
    Albuquerque, NM
    Vehicle:
    2006 Prius
    The way that graph shows the nonlinearity is certainly more accurate than the 5% per bar approximation.

    But I think the maximum for eight bars is understated, and the minimum for one bar.
     
    #6 archae86, Aug 22, 2008
  7. Bob64

    Bob64 Sapphire of the Blue Sky

    Joined:
    Apr 9, 2007
    1,540
    93
    0
    Location:
    Virginia
    Vehicle:
    2007 Prius
    Model:
    N/A
    2004 Prius capacity = 6.5 Ah * 201.6V = 1.3 KWh
    1.3 KWh * 40% available (40%-80%) = 520wh available
    520wh available / 100 = 5.2 wh per % (or 18,720 joules per %).

    fyi: a watt is not a unit of energy - It measures a rate of energy use or production.
     
    #7 Bob64, Aug 22, 2008
  8. Whiteyprius

    Whiteyprius Active Member

    Joined:
    Feb 24, 2008
    389
    105
    0
    Location:
    North Carolina, USA
    Vehicle:
    2017 Prius
    Model:
    Two
    I really appreciate all the responses, but I think that I'm in over my head! Is a bar really equal to (way approximately) to a leaf? I volts, watts, & Kw mean very little to me. Thanks!
     
    #8 Whiteyprius, Sep 2, 2008
  9. archae86

    archae86 Member

    Joined:
    Jun 19, 2008
    153
    24
    0
    Location:
    Albuquerque, NM
    Vehicle:
    2006 Prius
    No--they are not even equal to each other. Bars near the bottom represent much less energy than the highest blue or lowest green one do.
     
    #9 archae86, Sep 2, 2008
  10. Bob64

    Bob64 Sapphire of the Blue Sky

    Joined:
    Apr 9, 2007
    1,540
    93
    0
    Location:
    Virginia
    Vehicle:
    2007 Prius
    Model:
    N/A
    green leaf = 50wh
    each bar can be ~4%-14% "long"
    1% = 5.2wh
    9.6% = 1 green leaf

    So yes, it can equal one "Bar" or even two - depending on where on the chart it is. Just remember that each green leaf regenerates 10% and you'll be fine.
     
    #10 Bob64, Sep 2, 2008
  11. Whiteyprius

    Whiteyprius Active Member

    Joined:
    Feb 24, 2008
    389
    105
    0
    Location:
    North Carolina, USA
    Vehicle:
    2017 Prius
    Model:
    Two
    Thanks Bob64, and others! I'm even more impressed with the car's regenerative abilities according to the info I've received here, because I often see "Whitey" top off the battery on our little mountain jaunts:) He has delusions of grandeur when I resort to his Jake Brake - thinking that 18 wheelers are his peers. "Whitey" has quite an imagination.Is there a Prius shrink in the house?
     
    #11 Whiteyprius, Sep 3, 2008
  12. Whiteyprius

    Whiteyprius Active Member

    Joined:
    Feb 24, 2008
    389
    105
    0
    Location:
    North Carolina, USA
    Vehicle:
    2017 Prius
    Model:
    Two
    Speaking of Jake Brakes: I've discovered that the battery is not necessarily absolutely maxed out when the MFD glows that highest green bar. It takes feeding the battery thru regenerative braking a bit more before using the jake brake (B mode) engages with valves shut down - where "Whitey" begins to roar and clatter coming down the mountain, like the big guys.
     
    #12 Whiteyprius, Sep 3, 2008
  13. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,075
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    This is true. The MFD provides only a crud view of what's going on under the hood.

    Keep in mind that the Prius HV battery stores a relatively small amount of energy. It's only equivalent to a few ounces of gasoline, so it doesn't take much regenerative braking to fill it up. Think of it as a flywheel, storing a small amount of energy for quick use.

    Tom
     
    #13 qbee42, Sep 3, 2008
(You must log in or sign up to post here.)