Gen 4 12 Volt battery.

Discussion in 'Gen 4 Prius Technical Discussion' started by padroo, Feb 13, 2018.

  1. AzWxGuy

    AzWxGuy Weather Guy

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    According to my careful read of almost all of the 740 pages of my owner's manual we are no longer at risk for a flat 12 V from lights left on. I think most everything that could be left on will time out after 20 minutes. Finally, technology to the rescue.
     
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  2. Mendel Leisk

    Mendel Leisk Sand Pounder

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    I’ll believe that when I see it.
     
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  3. Prodigyplace

    Prodigyplace Senior Member

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    I do not trust the running lights to turn off on a timer. I set mine to turn off immediately.
     
  4. kithmo

    kithmo Couch Potato

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    Probably only the parking lights will stay on until the 12v goes flat.
     
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  5. alanclarkeau

    alanclarkeau Senior Member

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    Yes and no. I drive most of the daylight hours with parking lights (because I think it's more important to be seen from behind on a Motorway where I spend most time (and on my side of the road)) - and they turn off - they don't have a delay, but it's immediate.

    I have to manually turn to ON or AUTO for headlights at night.

    BUT - if I've got headlights on when I come in at night, I usually turn them to PARK as I come down the driveway (also so I don't alert the dog to me being home).

    One night, I forgot to flick them back to PARKERS, got out and [I think this is what I must have done] then reached back in and turned them to PARK. An hour or more later, my neighbour alerted me to my lights still being on. And the battery was too flat to start the system. I thought I'd rest it - went back an hour later and it had enough charge to start the car. I went for a drive - and sat with it in "D" for a while. That was 3 years ago - and the battery has been fine since.
     
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  6. jerrymildred

    jerrymildred Senior Member

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    True, as long as the technology works. My owner's manual confirms that they will eventually turn off, but also cautions not to make a practice of leaving them on so as to protect the 12V. (P. 517 in my manual)
    I'm not sure, though, if you don't get all the doors shut all the way of the lights will just stay on. So far, I've always noticed it when I didn't latch my door, but one of these days, I night not notice it.

    Also, I've seen lots of relays fail in my line of work, but so far, not in a car.
     
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  7. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Door ajar is what nearly always gets me. Or map lights, passenger visor vanity mirror light, or....

    When you've been nailed so many times, you tend to get skeptical.

    (That last sentence biblical humour?)
     
    #167 Mendel Leisk, Dec 23, 2020
    Last edited: Dec 23, 2020
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  8. AzWxGuy

    AzWxGuy Weather Guy

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    Well, I will venture a guess that monitoring has tightened up for 2021. I even got an LCD meter warning (what they call the two center-mounted dashboard displays, vehicle speed, fuel level, odometer, mpg, etc. now) when the driver's side power window was down maybe an eighth of an inch from closed. I can't find that particular warning in the owner's manual yet. I'm only up to page 693 though.
     
  9. AzWxGuy

    AzWxGuy Weather Guy

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    The owner's manual says those and even the emergency flashers will be turned off after approximately 20 minutes. I'll read it again just to make sure, but I think that is what I read.
     
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  10. alanclarkeau

    alanclarkeau Senior Member

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    You can (or at least used to be able to) get the Manual as a download from TOYOTA US website - meaning you can do a search.
     
  11. jerrymildred

    jerrymildred Senior Member

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    Yes, the manuals are still there. Searching a PDF file is sure a lot easier than searching a 35 pound paperback. :LOL:
     
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  12. AzWxGuy

    AzWxGuy Weather Guy

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    Oh yeah, downloaded the pdf lickity-split. The only way to fly.
     
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  13. alanclarkeau

    alanclarkeau Senior Member

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    Just not as easy to read a laptop in bed. The book makes good bedtime reading - a few minutes, and :sleep::sleep::sleep:.
     
  14. kithmo

    kithmo Couch Potato

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    I don't know if your US light switch is different to our UK one, but my manual only mentions that all the lights will turn off if the switch is left in the headlight position, not the parking light position and no mention of the emergency flashers turning off after a time.
     
  15. alanclarkeau

    alanclarkeau Senior Member

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    It's interesting the regional differences. I've been driving with ParkLights for probably 3 years or maybe more - and yes, they turn off. I haven't checked the book.
     
  16. jManfrey

    jManfrey New Member

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    i do not know if this has been posted yet in this thread but o'reilly sells a "140R" battery that is exactly the same size and seems to be working fine in my wife's prius. It was $150 at my local one
     
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  17. DonJuan1943

    DonJuan1943 Member

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    Enough of this! In the early 1960's they gave me a National Honor Society certificate. Not because I'm smart; but because I hung out with guys and gals like ya'll here. And I followed yall's advice. I bought new in 2016 a Prius 3 (grey), and I now I cannot think of a reason to part with it. New Michelines, 28000 miles, garage kept, unsmoked, unpuked, and nobody's ever had sex in it. I can find no reason to upgrade. But it has the original 12volt battery. I believe I'll upgrade the 12v battery. You've shown me why and how. Thank you all very much!
     
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