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12v battery at 4 years

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by yeldogt, Mar 8, 2016.

  1. yeldogt

    yeldogt Active Member

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    We had a no start condition about 6 weeks ago. One of the drivers was siting in the car for a while and could not remember what was On ... I should have just replaced the battery.

    Anyway, it died again last week.

    4 years and 130k. Replaced with a Bosch (rebranded Exide) from Pepboys. Paid $145 with discounts.

    I was surprised that many Honda's have the same size battery ... not a lot of reserve capacity.
     
    #1 yeldogt, Mar 8, 2016
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  2. sillylilwabbit

    sillylilwabbit Active Member

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    32k miles per year!

    Are you an Uber driver?


    My battery is 3.5 years, but I only 38k miles on the car and the voltage (with load and without load) seems to be holding up fine.

    Battery worries me as I would not like to be stranded somewhere.


    iPhone ?
     
    #2 sillylilwabbit, Mar 8, 2016
  3. yeldogt

    yeldogt Active Member

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    No Uber ...

    It's both a company car and it gets used for the family -- it's the most used car. It being much less expensive -- it's used a lot more for the generic running around.

    I was surprised. Maybe due to the size ? It is a small battery. I would have thought that a hybrid used often would have a longer lived battery? It may not mater.

    I do see people talking about the batteries failing. On our other cars with the battery not in the engine area they last a long time -- over 6 years.
     
    #3 yeldogt, Mar 8, 2016
  4. rstark18

    rstark18 Member

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    I just went out to my 2010 (Aug '09) and the lights blinked and flashed and sputtered out. I was literally thinking this morning how long my 12v has lasted (although I only have 40k miles).
    I made a few phone calls to see what was available locally and eventually decided on getting an Optima on Amazon for $160 after tax and free 2 day shipping with a trial Prime account.


    I have recently had worse gas mileage than any time in the last 5 years. I assumed it was an oil change I had done a while back. I thought maybe they used non synthetic. I'm now wondering if it was the bad 12v battery. We'll see in a couple days.
     
    #4 rstark18, Mar 8, 2016
  5. CR94

    CR94 Senior Member

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    True, despite the popular myth that a Prius's 12V is a lot smaller than any "regular" car battery. Batteries that skimpy in conventional vehicles are nothing new. Ford, for example, installed OE batteries of about the same AH capacity (but different physical dimensions) as a Prius 12V in full-size pickup trucks 50 years ago. Those old engines took more power to crank than a modern Honda's.
     
    #5 CR94, Mar 8, 2016
  6. ALS

    ALS Active Member

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    I replaced mine at 50 months. It seems that on average, four years is the normal life expectancy on this particular 12V.

    I'm going to automatically look at getting a new battery at 96 months
     
    #6 ALS, Mar 8, 2016
  7. yeldogt

    yeldogt Active Member

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    One thing ... make sure you get the correct terminals on the battery.

    I believe it is the Honda battery with the "R" in the model ......for reverse polarity ... or is it the Prius. Anyway .. I naturally got the incorrect battery. They are the same size.

    I jumped the car and went straight to Pep Boys -- When I started installing the new battery I noticed the terminals were reversed .... ??? ........ more importantly -- smaller diameter on the Prius.

    Well ......had to go back at some point anyway ... return the core. Thankfully, it's not far away.
     
    #7 yeldogt, Mar 8, 2016
  8. bisco

    bisco cookie crumbler

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    once you run it down, it's pretty much over. they don't like to be drained. mine is the same age, and like brand new. and it sits in the cold 5 weeks every winter.
     
    #8 bisco, Mar 8, 2016
  9. la9ers

    la9ers Junior Member

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    please keep us posted. i'm about the cross the 100k mile mark any day now on my 2012 and i'm wondering about the battery since its never been replaced. I also been suffering the mpg drop, i use to average 50 mpgs and now i'm in the low 40's.
     
    #9 la9ers, Mar 9, 2016
  10. alanwagen

    alanwagen Member

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    One sign of a failing aux battery is the drop in mileage. What will you do when it leaves you stranded? Replace it ASAP.
     
    #10 alanwagen, Mar 13, 2016
  11. yeldogt

    yeldogt Active Member

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    I don't see how the 12v battery has any connection to the vehicles MPG ... It would be interesting to understand the need for it. With the traction battery available -- I don't understand the need for it.

    I think I saw one with a CCA of 350 ... my other batteries are at 950 ... and a lot more reserve. With full LED lighting it would be less of a problem .. but with resistance lighting ... leaving on the interior lights will run it down.

    My battery is dead ... I jump the Prius to activate the car. The car starts the engine and runs it for 20 seconds and then shuts off. I take the jumper off .. and the car operates.

    The battery is still dead.
     
    #11 yeldogt, Mar 13, 2016
  12. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    That's 8 years, is that what you meant?
     
    #12 Mendel Leisk, Mar 13, 2016
  13. rstark18

    rstark18 Member

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    Since I had to wait a couple days to get the battery delivered from amazon, I charged the old one. It held over the next couple days just fine.
    When I received the new Optima battery I installed it and have driven it for a few days. My mpg went from 44 to 51. So I definitely had a bad cell.
    BTW when swapping out batteries if you have a charger hook it up before you start the swap out. By doing this you don't lose any settings on your nav, radio, etc. With the jumper terminals up front it's very easy and convenient.

    If you have a bad cell in your 12v the traction battery will constantly try to charge the 12v through the inverter because it thinks the 12v is too low. This constant charging lowers your MPG.

    [​IMG]
     
    #13 rstark18, Mar 13, 2016
  14. WolfpackBill

    WolfpackBill Senior Member

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    Mine is at 6 years now but it has only 82k miles. Not bad at all.
     
    #14 WolfpackBill, Mar 13, 2016
  15. yeldogt

    yeldogt Active Member

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    Well .. if that is what the car is doing,,, spending 8mpg to keep the tiny battery charged.. I really don't get why they need the 12v battery.
     
    #15 yeldogt, Mar 13, 2016
  16. la9ers

    la9ers Junior Member

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    just purchased an optima battery from jet.com using a new member 15% coupon it came out to $125 free shipping no tax.... will be reporting back regarding mpg's ...
     
    #16 la9ers, Mar 21, 2016
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  17. tweedle99

    tweedle99 Member

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    After reading this thread, I went ahead and replaced my OE battery from 10/09 with an Optima. Better be safe than stuck
     
    #17 tweedle99, Mar 21, 2016
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  18. Former Member 68813

    Former Member 68813 Senior Member

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    good deal. did you have to modify the terminals?
     
    #18 Former Member 68813, Mar 23, 2016
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