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

Brand new 12 volt battery not reaching 100% state of charge

Discussion in 'Gen 2 Prius Main Forum' started by GTW, Aug 7, 2018.

  1. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,604
    39,184
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Either way.

    The jump point under the hood is more convenient I think. The CTEK's also come with a quick connect. I didn't bother with it for years, just used the alligator clips, but now our car often sits idle for a day or three, and I keep the charger hooked up more often than not, so I did wire the quick connect.

    As I've installed it (patched into the 12 volt positive lead at fuse box, and a grounded bolt) I still need to pop the hood, but the connection is very secure, and I can lower the hood loosely, not locked, on the cord. In a pinch I think I could lock it, but we're in a secure garage.
     
    GTW likes this.
  2. audiodave

    audiodave Active Member

    Joined:
    Feb 3, 2017
    788
    269
    0
    Location:
    US
    Vehicle:
    2004 Prius
    Model:
    Five
    I charge mine once or twice a week since the Prius system doesn't seem to want to charge it properly.

    Posted via the PriusChat mobile app.
     
  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,604
    39,184
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I think it will charge it sufficiently, IF you've got a regular commute, decent length. But retirees, lots of idle time, maybe not sufficient.

    In a way a charger is good for the environment, you don't feel that obligation to drive it daily.
     
  4. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,790
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Makes absolutely no difference.
    Whichever is most convenient.
     
  5. GTW

    GTW Junior Member

    Joined:
    May 23, 2018
    55
    23
    0
    Location:
    Castroville
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    Is it not ironic that a car with a sophisticated High Votage charging system, has minimal low-voltage charging?
     
    audiodave likes this.
  6. Starship16

    Starship16 Senior Member

    Joined:
    Jun 8, 2018
    1,348
    1,454
    0
    Location:
    Beach Christmas
    Vehicle:
    2016 Prius
    Model:
    ----USA----
    Unless I become incapacitated, I try to drive daily, otherwise I get too bored. And I don't want to become a grumpy old homebound guy. :( But I only do about 25 daily miles. And maybe a short 50 mile higher speed freeway jaunt on the weekend. Is that enough? Or do I need to be looking at a Corolla...

    I'm learning that there are so many things different about this Prius. Should I just buy a new battery every 4 years? (play it safe.) When buying a new OEM 12V battery at the dealer, I wonder if they give it a charge before install.

    (No, I don't have a garage. Or a charger. Or a place to plug-in a charger. Or any tools. I'm on the third floor of a large treehouse)

     
    #26 Starship16, Aug 7, 2018
    Last edited: Aug 7, 2018
    Mendel Leisk likes this.
  7. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    I agree with Prius camper.You most likely bought a soft battery. We will never know because a simple voltage check done by you at time of purchase would have told the tale.

    Sometimes car batteries sit on there display rack a long time.
    When I bought my yellow top a few years ago after seeing so many story’s like yours here I brought my fluke dvm and had to go through 3 battery’s to find one that was charged,

    My bought new 07 keeps my battery at 12.6 volts sitting. Same voltage the stock battery measured sitting since birth.
    The stock battery is far superior imho than a yellow top.

    Do this simple test. With car off measure battery voltage at front jump point. Write that Down. With car off put headlights on high beam for 5 minutes and then measure again. My 4 year old yellowtop does not drop one volt in this test.
     
    GTW and George W like this.
  8. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Ps
    At 12.6 volts and trickled charge at 2 amp it takes forever to reach 13.8 volts like 2 days.

    It’s a long long way to tipperary from 12.6 to 13.8 trickle charging.

    My bought new in 07 never measured higher than 12.6 sitting with very healthy monthly maintence charges. That battery lasted 7.5 years so the car is doing something right.

    On the other hand My Crown Vic with a huge high quality battery lives at 13.2 sitting.
     
    #28 edthefox5, Aug 7, 2018
    Last edited: Aug 8, 2018
  9. Lucifer

    Lucifer Senior Member

    Joined:
    Aug 23, 2015
    1,014
    486
    0
    Location:
    Nh
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    Ah, not a yellow top equivalent but a yellow top, got it.

    The reason we and Toyota put a deep cell battery in the prius is that it's such a small weak battery, it goes ded in ten minutes if left in acc mode, and when it goes ded, simply trickle charge it and it's like new.
     
  10. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,844
    3,960
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    If it goes dead in 10 minutes, then your battery is EOL (end of life). Replace it.

    I can run my car on ACC (just the radio, usually) for hours. But then again, I maintain my battery to ensure it does sit for any length of time discharged, as sitting discharged will kill it in no time.

    Incidentally, my 12 V holds 12.9 V 3 years down the track. It held 13.2 V when new.
     
    #30 dolj, Aug 8, 2018
    Last edited: Aug 8, 2018
  11. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,604
    39,184
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    EOL equals End Of Life?
     
  12. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,790
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    No......because it has a minimal NEED for low voltage current.
     
  13. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,790
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Yes, an average of 25 miles per day is plenty.......IF THE CHARGING SYSTEM IS WORKING RIGHT.
    PLEASE HAVE IT TESTED. PLEASE. You seem to be ignoring that critical piece of advice.

    And the things that are different about a Prius are not really important to the average driver.
    It was designed so that you could get into it and JUST DRIVE IT, just like any other car.

    If something goes wrong, you get that fixed.......just like any other car.

    If you just DO that, you should feel much less stress.
     
    Starship16 likes this.
  14. Starship16

    Starship16 Senior Member

    Joined:
    Jun 8, 2018
    1,348
    1,454
    0
    Location:
    Beach Christmas
    Vehicle:
    2016 Prius
    Model:
    ----USA----
    Thanks Sam.

    Just drive it.... :D
     
  15. GTW

    GTW Junior Member

    Joined:
    May 23, 2018
    55
    23
    0
    Location:
    Castroville
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    Yet there are Accessories that are ''warned' as discharging the battery if left unattended too.
     
  16. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,027
    49,994
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i don't know if it is ironic, but toyota may have a reason. the battery is so small, maybe faster charging would shorten the life.
     
  17. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,790
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    None of the factory "accessories" draws a significant amount of current, if the vehicle is properly turned OFF.
    After-market accessories might be a whole different story.
     
  18. GTW

    GTW Junior Member

    Joined:
    May 23, 2018
    55
    23
    0
    Location:
    Castroville
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    Toyota included a smart key off switch under the steering wheel.
     
  19. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,790
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Are they still doing that on the new models ?
    I don't think my C has that.
     
    Starship16 likes this.
  20. Starship16

    Starship16 Senior Member

    Joined:
    Jun 8, 2018
    1,348
    1,454
    0
    Location:
    Beach Christmas
    Vehicle:
    2016 Prius
    Model:
    ----USA----
    I don't have it.