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

New HV Battery Question

Discussion in 'Gen 3 Prius Main Forum' started by ALS, Sep 7, 2018.

  1. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    Got a new HV pack in my car today and was wondering how long it takes for the computer to reset and adapt to the new pack. Gas mileage isn't that great in the first day. It is climbing, but not as quickly as it use to.

    I know it takes a little while but what am I looking at time was before things get back to normal.
     
    #1 ALS, Sep 7, 2018
  2. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,251
    15,476
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    How many miles have you put on the car since the new battery install?

    What mpg are you at and where were you at before?

    How many miles on your Prius?
     
    #2 Raytheeagle, Sep 7, 2018
  3. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,097
    5,809
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    Personally, I understand the thought behind this, but have yet to experience it.

    In theory....if the 12v is disconnected during car maintenance, many "tweaks and adjustments" made by the ecus are reset to default and this can cause running issues when there are components (like a throttle body) that have wear/tear/carbon buildup/etc. I've even heard of times the car won't start due to the throttle body having enough buildup that the throttle plate is not in the correct position for the default values.

    In reality, I haven't yet experienced this issue following an HV battery replacement, even though I disconnect the 12v battery every time I swap one. After building a battery and installing it in my car, I always take it for a test ride to my work parking lot 23 miles away (46 miles round trip) staying within 5 mph of all speed limits. My experience has been instant 48-53 mpg.

    If you're having significant issues with mileage, maybe disconnect the 12v for a minute and then take it for a 40-50 minute drive of backroad (40mph) and highway (65 mph) and see how it does after that.
     
    #3 TMR-JWAP, Sep 7, 2018
    jerrymildred likes this.
  4. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    78K miles. New 12V about three months old. Low thirties before battery went to limp home mode and I got the dead battery walking code.
    Still in the low thirties and I put on about twenty five to thirty miles so far.
     
    #4 ALS, Sep 7, 2018
  5. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,251
    15,476
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Did toyota help you with the battery replacement?

    I’d run a tank or 2 before making an assessment of the replacement.
     
    #5 Raytheeagle, Sep 7, 2018
  6. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    Yep Toyota gave me $750 and I got the dealer to discount the battery a few hundred. $2285 with labor and tax for a brand new Toyota battery. Not happy that I had to put a new battery in but it could have been much worse like $3,500

    That was what I was thinking that it's going to take the computer a few hundred miles to calibrate itself to my driving style.

    Already seeing a really big difference in the behavior of the car. There was this bump that felt like a normal transmission kicking into gear when I would accelerate from a stop. That has disappeared completely with the CVT transmission is running smooth now.
     
    #6 ALS, Sep 8, 2018
    m.wynn and Raytheeagle like this.
  7. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,251
    15,476
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Having a new battery you will notice a difference.

    I recondition our 2010’s battery and prior to doing that, you could tell it was getting tired at 150k miles. Since reconditioning, it’s running well.

    We have a 2017 RX450h so I have a nearly new hv battery to compare behavior against.

    As you put more miles on, keep us posted on the differences(y).
     
    #7 Raytheeagle, Sep 8, 2018
    ALS likes this.
  8. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    Low tire pressure light came on this morning so add to the fact that the dealer lowered all my tire pressures by 8-9 psi. That problem was corrected pretty quickly.
     
    #8 ALS, Sep 8, 2018
    Raytheeagle likes this.
  9. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,113
    4,040
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    What was the solution to that? Interested because it was resolved “pretty quickly.”
     
    #9 Grit, Sep 8, 2018
  10. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,470
    8,383
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    I would check for a nail in your tire
     
    #10 JC91006, Sep 8, 2018
  11. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    Free air pump at the local quarter car wash. Pressures are back up to 42F 40R.
    That's better than the 32-33 psi the dealer set them at.
     
    #11 ALS, Sep 8, 2018
    bisco and Raytheeagle like this.
  12. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,113
    4,040
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    I was expecting something pretty quick, I had a different idea.
     
    #12 Grit, Sep 8, 2018
    ALS likes this.
  13. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    Just filled up with my second tank of gas since replacing the traction battery earlier this month. Wasn't impressed with the fuel mileage I got on that first tank 36.13 mpg. Two days into this second tank of gas it's a whole new story. The HSI is showing over 45 mpg and my Scan Gauge is running over 50 mpg on most of the errands I'm running during the day.

    So right now mpg's are improving as I drive the car. I'll let you know what this second tank gives me in a few weeks.
     
    #13 ALS, Sep 22, 2018
    bisco and Raytheeagle like this.
(You must log in or sign up to post here.)