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

At what point do you replace the 12v battery?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by mikefocke, Jul 1, 2016.

  1. mikefocke

    mikefocke Prius v Three 2012, Avalon 2011

    Joined:
    Nov 3, 2012
    3,626
    1,623
    0
    Location:
    Sanford, NC
    Vehicle:
    Other Hybrid
    Model:
    Limited
    For the record, I haven't changed the battery. It is original 4+ years and 36k miles later. If I still have the car in the summer, then I'll replace the battery.
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i'm up to 49k. battery is STRONG.:cool:
     
    mmmodem likes this.
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Yeah, just like the stock market.
     
    bisco likes this.
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i'm in cd's.:oops:
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Safe as houses!
     
    bisco likes this.
  6. mhagadorn

    mhagadorn Junior Member

    Joined:
    Aug 30, 2013
    28
    6
    0
    Location:
    Western Pennsylvania
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I replaced the 12v battery in our (now traded-in) 09 Prius at about 80k miles. It would die (not "start" the car) if the interior lights were left on for more than a few minutes. Learn how to jump start your Prius (it is in the manual) and carry jumper cables.

    One stupid thing we learned. My wife was on a trip and pulled in to a rest stop to take a nap at night. She always leaves the headlights switched on, and lets them "auto" off. This works fine as long as you open the door. In this case, she stopped the car, turned it off, and went to sleep. Because she never opened the drivers side door, the lights never turned off. They drained the 12v battery completely. Toyota should be smarter than that.
     
    bisco likes this.
  7. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it's an unsolvable engineering problem. apollo 13 was easier.
     
  8. breaker1nine

    breaker1nine Junior Member

    Joined:
    May 18, 2011
    5
    5
    0
    Location:
    Brooklyn, NYC
    Vehicle:
    2011 Prius
    Model:
    Two
    Are these readings for a battery that hasn't been running for a bit?

    I left my 2011 Prius off for a couple of hours, and I tested it with a digital multimeter I got readings of 12.06 and falling. And strangely, also, 11.96 and falling. Falling, meaning the reading drops.
    This is the original battery, I'm the first/only owner and I bought the car in April 2011.

    If I don't start he car for 2 days, it's a crap shoot as to whether or not the car will start without a jump start.
     
    #28 breaker1nine, Mar 4, 2018
    Last edited by a moderator: Mar 5, 2018
  9. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Original battery, I would just replace.
     
    padroo likes this.
  10. breaker1nine

    breaker1nine Junior Member

    Joined:
    May 18, 2011
    5
    5
    0
    Location:
    Brooklyn, NYC
    Vehicle:
    2011 Prius
    Model:
    Two
    Thanks.
    Is this list still a good standard for replacements? 12V battery List | PriusChat
    Seems prices have changed significantly. The Optima listed at $147.05 on Amazon in the posting is now $289.99.


     
  11. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    The $289 prices sounds like a case of limited supply, not the norm. I've kinda gone off Optima Yellow Top, and I have one. No problems 3 years in, but I've heard it has inordinately high Cold Cranking Amps, at the expense of amp hours. Internally that's achieved through more/thinner plates?

    In the States Pep Boy seems to regularly have a conventionally shaped AGM by Bosch on sale, for around $145, and they'll even install for that price? As far as I know it's dimensionally identical to the the OEM Yuasa, with decent spec's.
     
    breaker1nine likes this.
  12. mikefocke

    mikefocke Prius v Three 2012, Avalon 2011

    Joined:
    Nov 3, 2012
    3,626
    1,623
    0
    Location:
    Sanford, NC
    Vehicle:
    Other Hybrid
    Model:
    Limited
    I did change mine after around 40k miles and 5+ years. Part of a diagnostic approach on another problem and the dealer installed price was less than $200. Since I was going to do it anyway in a month or so I even suggested it. In hindsight it wasn't the battery but I'm glad I did it anyway.
     
  13. breaker1nine

    breaker1nine Junior Member

    Joined:
    May 18, 2011
    5
    5
    0
    Location:
    Brooklyn, NYC
    Vehicle:
    2011 Prius
    Model:
    Two
    Thanks!
    I'm going to move forward and I'll get this one:
    Bosch Premium Performance Battery Group, Size 51 - $142.49 including installation.


     
    Mendel Leisk likes this.
  14. padroo

    padroo Senior Member

    Joined:
    Jan 11, 2008
    2,763
    2,250
    13
    Location:
    Chesterton, Indiana Another third world country.
    Vehicle:
    2016 Prius
    Model:
    Four

    That's a great price.
     
    breaker1nine likes this.
  15. breaker1nine

    breaker1nine Junior Member

    Joined:
    May 18, 2011
    5
    5
    0
    Location:
    Brooklyn, NYC
    Vehicle:
    2011 Prius
    Model:
    Two
    Yeah. 25% off until April 1, 2018.

     
    padroo likes this.
  16. breaker1nine

    breaker1nine Junior Member

    Joined:
    May 18, 2011
    5
    5
    0
    Location:
    Brooklyn, NYC
    Vehicle:
    2011 Prius
    Model:
    Two
    Thanks for your help.
    I got the Bosch Premium Performance Battery Group, Size 51 - for $142.49 including installation Pep Boys. The car starts perfectly, now. I don't even think about the possibility of having to jump start it.

     
    benagi, Mendel Leisk and padroo like this.
  17. padroo

    padroo Senior Member

    Joined:
    Jan 11, 2008
    2,763
    2,250
    13
    Location:
    Chesterton, Indiana Another third world country.
    Vehicle:
    2016 Prius
    Model:
    Four
    I worked for a guy that had a saying, "When in doubt, change it out".

    Good luck with your car.
     
    benagi likes this.
  18. Hawkizrok

    Hawkizrok Junior Member

    Joined:
    Jun 19, 2009
    10
    0
    0
    Location:
    Marion
    Vehicle:
    2006 Prius
    Model:
    N/A
    When switching out the 12V battery is it essentially unplug the old and plug in the new? Didn't know if there was more to the process than that.
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I'd suggest something like this:

    1. Disconnect negative cable clamp at battery post, that's the one that's not red. Maybe stuff it into a heavy rubber-lined glove, just to keep it isolated. A 10 mm box wrench is likely best for this. Take care to never make a circuit between the two posts, say a wrench handle or extension, a stray wire, or whatever. Just don't give it a path between the two.
    2. Disconnect the positive (red) cable similarly.
    3. Loosen and remove the battery hold-down bracket.
    4. Lift out the old battery.
    5. Clean the posts of the new battery, say with a scrap of fine sandpaper. Also clean the insides of the cable clamps. There are wire brushes purpose designed for this, though they tend to be on the big side, for regular size post clamps. Use what you have, again sandpaper will work. Just get everything to shiny metal. Be cautious with the post dust, it's lead.
    6. Put in the new battery, install the hold-down bracket, and install the clamps in reverse order: red first, then black.

    Some caveats:

    a. It would be good to pre-charge the new battery, with a smart charger, 3~4 amp range. Let it run to completion, might take 8 hours or so. It's not mandatory, if you've got a fairly fresh battery and are going to be driving a lot it'll be fine. But if you have the charger and the time, it's good practice.
    b. You will lose some of the car's memories if you don't employ some sort of memory saver. You can either research that, or just resign yourself to having to reset a few things. The trip meters will reset, radio presets will be gone, and if the car has auto-up windows that may need to be "relearned". You may be ok on that. It's not the end of the world, and there are procedures to remedy the window issue, if it happens.
    c. Check conditions under the battery while you have the old one out: there may be water collecting, for example.
     
    davecook89t and taxibuddy like this.
  20. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,470
    6,862
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    (I have a 120,000 mile/10 year service coming up August 16th)
    I have been noticing my head lights get brighter about a second after I start the car for the past two weeks. Today I altered my Scan Gauge II to display volts instead of intake Air Temperature F. When I turned it off, I had 12.1 volts. (14.7 volts when running) I am going to monitor it cold each morning, but it is clear the battery is on my replace list when I go to the dealer in August.