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

12V Battery's Life Expectancy

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by rcshaw777, Aug 21, 2011.

  1. chronon

    chronon Active Member

    Joined:
    Jun 14, 2007
    601
    105
    3
    Location:
    here and there aint be in frozen wasteland no mo..
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    have u guys seen the guy on utube that uses a capacitor battery ? 6 'supercaps' that start his corrolla --- this is a nearly 'last forever' 12V battery - no water, smaller space , a lot less weight and costs about $35 for the unit and some time makign some casing and conductor connecting ...
     
  2. Jaswong00

    Jaswong00 New Member

    Joined:
    Apr 24, 2013
    2
    0
    0
    Location:
    Chino Hills CA
    Vehicle:
    2010 Prius
    Model:
    V
    I recently bought a 2010 Prius pkg V with 82k miles and I was getting low 40smpg, after doing tune up(new 12V battery, tranny oil changed, motor oil changed, spark plugs changed), I am getting 50smpg now. Hope this helps.
     
  3. Jaswong00

    Jaswong00 New Member

    Joined:
    Apr 24, 2013
    2
    0
    0
    Location:
    Chino Hills CA
    Vehicle:
    2010 Prius
    Model:
    V
    oh btw, i did the battery test before changing the 12V battery, the test shows 11.6V when I hit the start button after the car sit overnight. The load test shows 10.5V with low beam on, heater fan full blast, and dome lights on. I did not want to get stranded someone and I wanted to improve my mpg, so I replaced the battery and did all the tune up...
     
  4. chronon

    chronon Active Member

    Joined:
    Jun 14, 2007
    601
    105
    3
    Location:
    here and there aint be in frozen wasteland no mo..
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    yit is utterly amazing that such a sophisticated machine, with all the computer control inside this car and all the emphasis on MPG , would suffer a 10%!!! decrease in milegae because of the 12V auxillary source fading to black .... it shows that toyota engineering was not caring about the long haul, only short term (bat expectancy 5 years andnew model intro at end of lifetime) -

    what about people that leave there car on , listen to the radio , door ajar, etc. --- i guess they learn the lesson early !!!
     
  5. Ridder

    Ridder Member

    Joined:
    Dec 7, 2012
    141
    51
    0
    Location:
    Netherlands
    Vehicle:
    2011 Prius
    Model:
    Three
    When the car is "on" the juice (even for charging the 12V battery) comes from the HV battery.
     
  6. chronon

    chronon Active Member

    Joined:
    Jun 14, 2007
    601
    105
    3
    Location:
    here and there aint be in frozen wasteland no mo..
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    i believe that's true, so then i guess the engine is taking more power (gas) to charge the HV which in turn
    must charge the LV (aux)
     
  7. The Critic

    The Critic Resident Critic

    Joined:
    Oct 28, 2005
    3,193
    2,315
    0
    Location:
    CA
    Vehicle:
    2011 Prius
    Model:
    Three
    The lifespan will vary by climate and the individual usage pattern. It is a good idea to have the battery load-tested at each oil service with a Midtronics to verify its state of health.


    iPhone ?
     
  8. Ridder

    Ridder Member

    Joined:
    Dec 7, 2012
    141
    51
    0
    Location:
    Netherlands
    Vehicle:
    2011 Prius
    Model:
    Three
    My 12V battery has been depleted twice and I suspect it is having a negative effect on FE.
    I have a WiFi OBD2 dongle in the car that is always on.
    Yesterday, after a night rest, I checked the voltage and it was 12.09 Volts.
    Today I took out the dongle and drove for a while to fully charge the 12V battery (I know I don't have to drive....) and to see how efficient I can drive.....it was perfect weather for Prius: low 70's and I only took 60 and 80 km/h roads.
    The result was 3.9 l/100km. (that's 60 MPG I think).
    I drove 30 miles.
    One hour after the drive I measured again and the voltage was 12.47 Volts now.
    The first measurement was with the dongle in the car the whole night.
    The car has 10K miles on it.
     
  9. alfon

    alfon Senior Member

    Joined:
    May 17, 2009
    1,370
    270
    0
    Location:
    seaside, oregon
    Vehicle:
    2010 Prius
    Model:
    III
    I am nearing 100,000 miles on our Prius and it was purchased 4 years ago. Living on the coast we have moderate
    weather and seldom does temp go past the mid 80's. Winter is in the mid 30-s to 50's.

    I have a scan gauge and does anyone know what I need to do to see if the 12V battery is up to standards. I believe
    the gauge does have a volt meter built in....
     
  10. chronon

    chronon Active Member

    Joined:
    Jun 14, 2007
    601
    105
    3
    Location:
    here and there aint be in frozen wasteland no mo..
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    like the guy said , load tester .. or u could just go to a place like autozone or advance auto and get a free test.. oh wait, not sure they know how to do a hybrid .. part of their test involves running the car on demand - u will have more luck at a larger place with higher volume of cars than a smaller store and low customer count as that one will more likely have a guy that throws his hands in the air ...
     
  11. Jon Hagen

    Jon Hagen Active Member

    Joined:
    Mar 6, 2011
    336
    136
    0
    Location:
    North Dakota
    Vehicle:
    Other Hybrid
    Model:
    N/A
    On some, like my early 2010 Prius (bought in July 09) it does have a removable cap over the valve regulated vents, BUT it's an AGM battery and should not show any electrolyte above the plates. There is a sticker on the battery warning to not remove the cover or add water. Most AGM batteries are not designed to be refilled.
     
  12. prius cabbie

    prius cabbie Junior Member

    Joined:
    Apr 28, 2013
    14
    1
    0
    Vehicle:
    2013 Prius
    Model:
    Two
    Is this a joke?
     
  13. chronon

    chronon Active Member

    Joined:
    Jun 14, 2007
    601
    105
    3
    Location:
    here and there aint be in frozen wasteland no mo..
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    perhaps
    perhaps this is for someone that has replaced the glass-gel-pack with a regular lead-acid substitute like the mazda miata call number
     
  14. sunvia

    sunvia Junior Member

    Joined:
    Jul 28, 2010
    67
    8
    0
    Location:
    palm springs,ca
    Vehicle:
    2010 Prius
    Model:
    II
    my 2010 OEM battery just quit....I have 72,000 miles on it.....my gas mileage has dropped, so maybe this new one will help that too.....i'm replacing with optima yellow top
     
    Mendel Leisk likes this.
  15. CrazyLee

    CrazyLee Member

    Joined:
    Aug 3, 2014
    153
    24
    0
    Location:
    Muskegon, MI USA
    Vehicle:
    2004 Prius
    Model:
    II
    Fun with 12v batteries.
    in April 2014 I replaced my Toyota 12v battery, thinking my low fuel mileage was caused by that. I bought an Exide AGM51JIS battery.(Larger size) It really didn't help much in the fuel department.

    It seemed to have a longer life for discharge though. I did have several discharge cycles on it that winter. It seemed to rebound OK. This fall it had gotten really cold early and he battery went flat. I pulled it and replaced it with the original Toyota battery. I had kept it on a float charger all that time. I'm glad I kept that battery.

    A week later running the Exide battery, the Exide died again with very low temps. (10 F)
    Because I couldn't open the rear hatch, I crawled in back through the passenger side back door, dropped the seat backs and removed the floor cover and plastic tray, placing them sideways over the driver side back seat that I tilted down.

    I have found if you lift the hood and put a battery in the charging posts first you don't lose the clock or radio settings. My chicken dances don't get clobbered either. Please don't allow the battery + wire to short to ground.

    I was able to remove the brake ECU and unbolt the battery ground clamp and +12v battery clamp, and drag out the bad battery and replace it.

    So since I have a warranty I requested a refund.
    I don't want to see that experience again. I'm going to my local Toyota dealer for my next 12 v battery.
     

    Attached Files:

  16. Former Member 68813

    Former Member 68813 Senior Member

    Joined:
    Oct 3, 2010
    3,524
    981
    8
    Location:
    US
    Vehicle:
    Other Hybrid
    Model:
    N/A
    My OEM mid 2010 battery is still good 6.5 years later. I made care to never deep cycle it. The location of the battery and protection from engine heat is great.

    I think they changed that in new gen.
     
    #36 Former Member 68813, Jan 6, 2017
    Last edited: Jan 6, 2017
  17. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,468
    38,103
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I think once you crawl through the car to the back there's a mechanical hatch release switch: you push that and hatch will pop open, dead battery or not. At least there is on 3rd gen, not that sure on 2004. I hate to spoil your fun though, lol.
     
  18. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    if you put a good battery on the charging post, why can't you open the hatch from outside?
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,468
    38,103
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    We're having too much fun now. :)
     
  20. lefteye219

    lefteye219 Junior Member

    Joined:
    Aug 22, 2012
    32
    4
    0
    Location:
    New Jersey
    Vehicle:
    2010 Prius
    Model:
    Three
    I have a 2010 Prius, about 147K miles on it now. My battery hasn't died yet. Had it for a little over 6 years and the battery is still good.
     
    Raytheeagle and bisco like this.