Suggestions to maintain 12v battery life

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by bugaboo416, Apr 6, 2015.

  1. bugaboo416

    bugaboo416 Junior Member

    Joined:
    Mar 8, 2011
    10
    3
    0
    Location:
    US
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    My prius Gen2 2009 is being stored in a garage. The location does not have access to an electrical outlet. Recently I had to leave it for 2 months and when I came back, the 12v battery was dead. I had to get a jumpstart to get going again. I will be travelling more often for 2 month stints so I expect this will be happen each time.

    Short of having someone stop by to run my car for an hour a week or uncoupling the battery completely, are there any suggestions on how to maintain the life of the 12v battery while I am away?
     
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    14,135
    6,844
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2010 Prius
    Model:
    V
    You can simply just disconnect the negative battery terminal that bolts onto the car's body. It's easily accessible and you only need a 10mm socket/wrench. With the negative disconnected, your battery (if in good condition now) should be good after 2 months.
     
    #2 JC91006, Apr 6, 2015
    Last edited: Apr 6, 2015
  3. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    253
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    Nope.
    Not unless you can connect a small solar charger to keep it charged.
    And running it without driving isn't a very good idea either.

    Regardless of what you do, the battery probably won't last long either........now that it's gone really flat once.

    Simply disconnecting it without a float charge might not do the trick either.......depending on how healthy it is.l
     
  4. frodoz737

    frodoz737 Top Wrench

    Joined:
    Aug 26, 2010
    4,225
    2,151
    33
    Location:
    Texas
    Vehicle:
    2015 Prius
    Model:
    Four
    Disconnect both terminals for long term storage.
     
  5. mosesk

    mosesk Member

    Joined:
    Feb 23, 2013
    124
    14
    0
    Location:
    Ventura County, California
    Vehicle:
    2009 Prius
    Model:
    Two
    I was just in the exact same situation.
    You can follow my saga over here:
    Dead | PriusChat
     
  6. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    253
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    What? Why ??
    There is NO reason to disconnect both.......unless you are actually removing the battery to be maintained elsewhere.
     
  7. frodoz737

    frodoz737 Top Wrench

    Joined:
    Aug 26, 2010
    4,225
    2,151
    33
    Location:
    Texas
    Vehicle:
    2015 Prius
    Model:
    Four
    Why wouldn't you is more the question. There are literally hundreds of reasons why you do this, but the main one is to "completely" isolate of power supply. Have you ever seen batteries "stored" (not charging) with any cable hooked up? It's just one more fastener.
     
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    86,361
    38,262
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i like the solar charger idea.
     
  9. Munpot42

    Munpot42 Senior Member

    Joined:
    Mar 12, 2012
    1,382
    527
    0
    Location:
    Santa Monica, Ca. 90405
    Vehicle:
    Other Hybrid
    I think the 09 has a way to turn off the sks, that might help because it is always looking for the "key".
     
  10. wjtracy

    wjtracy Senior Member

    Joined:
    Sep 19, 2006
    10,823
    3,315
    1
    Location:
    Northern VA (NoVA)
    Vehicle:
    2006 Prius
    ^^^Right if you have the Smart Key System (SKS) on a Gen2 you have a button under the steering column to turn it off. Then you have to use the real key to open the door and then you can restart the SKS system by pushing the button.

    Just did this at the airport last week.

    The other thing I like to do (after car sits a week) is warm up car several minutes and keep A/C off for the first 5-10 minutes. After it has sit for a week it seems to be easy to drain the HV battery to purple leaving the airport in a rush with A/C blowing, so I give it until the engine cuts out before I pull out (2 or 3 minutes), and go easy on the A/C.

    Re: 12v keep in mind Prius charges up the 12v quite slowly so need some decent hour trips to really get a good charge. For 2-months disconnecting lead seems appropriate.
     
    #10 wjtracy, Apr 6, 2015
    Last edited: Apr 6, 2015
  11. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    253
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    Because it totally, absolutely, completely unnecessary........and somewhat dangerous to be messing with the + post if you don't have to.

    You "isolate" a battery by breaking the circuit. One post is all that is necessary to do that.

    We are not talking about trying to prevent damage from a lightning strike here.
     
  12. frodoz737

    frodoz737 Top Wrench

    Joined:
    Aug 26, 2010
    4,225
    2,151
    33
    Location:
    Texas
    Vehicle:
    2015 Prius
    Model:
    Four
    If one thinks it's dangerous to remove the 12 VDC positive cable on a Prius (after the negative cable first of course), them they don't understand even the basics and should not touch the battery to begin with...god forbid ever change one. We are talking about isolating a power supply for "storage" and one more fastener. Do what you want.
     
  13. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,091
    671
    0
    Location:
    sterling, VA
    Vehicle:
    2006 Prius
    it would be a pita, but you might consider removing the battery from the car since there's no outlet nearby, and put it somewhere safe with a Battery Tender hooked to it. when you get back at least you know your battery will be fully charged.
     
  14. frodoz737

    frodoz737 Top Wrench

    Joined:
    Aug 26, 2010
    4,225
    2,151
    33
    Location:
    Texas
    Vehicle:
    2015 Prius
    Model:
    Four

    Attached Files:

    #14 frodoz737, Apr 7, 2015
    Last edited: Apr 7, 2015
  15. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    253
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    There is no "of course". You did not qualify your suggestion the first time.

    And that is most of the point. People have defective memories. They might remember you said to take off both cables but forget that you also said to do the negative first........and use their un-insulated box wrench.......in which case it IS dangerous.

    It is NOT necessary to disconnect both posts.
    With one already off, what exactly do you think you are accomplishing by removing the other ??
    Answer: nothing.

    You are perfectly free to do whatever stupid thing you want; just don't try and convince others that it is a good idea.
     
  16. frodoz737

    frodoz737 Top Wrench

    Joined:
    Aug 26, 2010
    4,225
    2,151
    33
    Location:
    Texas
    Vehicle:
    2015 Prius
    Model:
    Four
  17. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    86,361
    38,262
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
Loading...