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

Rapid cycle between charge/dischrge

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by JoelO, Oct 23, 2008.

  1. JoelO

    JoelO New Member

    Joined:
    Oct 23, 2008
    1
    0
    0
    Location:
    Minneapolis
    Vehicle:
    2009 Prius
    I just took delivery of my Prius last week and do not know if what I'm seeing is normal. Has anyone else seen this and is it normal?

    While at highway speed (60-75 mph) on level terrain - both with and without cruise control - I see the battery cycle between charge and discharge at a rate faster than 2 cycles per second. The display shows charging for a period of a few seconds and then enters a cycle of rapid charge/discharge for several seconds before settling back to several seconds in a charge state. When accelerating or going up/down hill this does not happen for the obvious reasons. I swear that I can feel the power fluctuations as well but that might be my imagination.

    I understand why the system would cycle, I'm just concerned that such a rapid frequency is a symptom of a problem.
     
    #1 JoelO, Oct 23, 2008
  2. ddan

    ddan New Member

    Joined:
    Oct 14, 2008
    14
    1
    0
    Location:
    Bryn Mawr
    Vehicle:
    2009 Prius
    I hope not.... I have noticed the same thing, though I can't remember feeling surges. I am a new Prius driver as well (<2 weeks). Avg 51 mpg so far.
     
    #2 ddan, Oct 23, 2008
  3. efusco

    efusco Moderator Emeritus
    Staff Member

    Joined:
    Nov 26, 2003
    19,891
    1,193
    9
    Location:
    Nixa, MO
    Vehicle:
    2004 Prius
    Model:
    N/A
    Totally normal and exactly what the car should do. The Engine will run at a nearly constant RPM, that means sometimes it produces a little more energy than is being demanded and will show charge to the battery, when it needs a little more it take some from the battery...all part of maintaining maximum MPG.

    Those of us with instrumentation to watch know that those fluxes are very small, usually less than 6-12 amps either direction.
     
    #3 efusco, Oct 23, 2008
  4. john1701a

    john1701a Prius Guru

    Joined:
    Jan 6, 2004
    12,766
    5,251
    57
    Location:
    Minnesota
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    The video download from this webpage provides a sample of what we normally see... much like you described.

    .
     
    #4 john1701a, Oct 23, 2008
  5. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
    Staff Member

    Joined:
    May 11, 2004
    14,816
    2,498
    66
    Location:
    Far-North Chicagoland
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Since no one else said it, :welcome: welcome to PriusChat and congrats on your new Prius!
     
    #5 TonyPSchaefer, Oct 23, 2008
  6. ddan

    ddan New Member

    Joined:
    Oct 14, 2008
    14
    1
    0
    Location:
    Bryn Mawr
    Vehicle:
    2009 Prius
    Thank you. Have been reading and learning tons. Great people and info!
     
    #6 ddan, Oct 23, 2008
  7. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,041
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    Now, if you were seeing the number of bars on the state-of-charge display change by two bars per second, that would be bad.
     
    #7 richard schumacher, Oct 23, 2008
(You must log in or sign up to post here.)