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Battery Goes Down 4 bars in 1 minute???

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by unit333, Jan 2, 2010.

  1. unit333

    unit333 Junior Member

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    Hi
    I was driving today and my battery indicator was almost completely full (just 1 bar less than 100%).
    A few minutes into the trip I looked back at the indicator and the battery looked almost empty (2 bars remaining) Not sure how to look about this if its just nothing, or if the indicator got confused? Anyhow I parked later and went back to the car again, drove for about 30 minutes and the battery pretty much went back to its normal state from before. This is brand new thing to me though it really didn't happen at all in the past week since I got the car. Any explanations?
    I am in New York, its pretty cold right now if that matters.
     
    #1 unit333, Jan 2, 2010
  2. efusco

    efusco Moderator Emeritus
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    Yes, the cold matters.
    What were the road conditions? Traffic? Speed? What mode were you in (eco/power?)? What did you have the climate control set to? Was this seen from a cold start or was the car warmed up when you noticed the SOC drop? Were there hills or flat terrain? Stop and go or steady speed?

    With that info we can probably give you a reasonable explaination of what happened. But, the bottom line is that I would not worry about it, the car takes care of itself and the SOC can vary under various conditions.
     
    #2 efusco, Jan 2, 2010
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  3. Paradox

    Paradox Prius Enthusiast / Moderator
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    I know what you mean about it being cold in NYC right now, and knowing the temperature I'm sure you had the heat on. That coupled with everything else Evan has noted I would not worry about it. The car will manage the battery itself.

    I realize when one first gets a Prius they watch every new little nuance the Prius has over a conventional car but unless some 'idiot light' comes on and stays on don't worry about things like this too much. :) Enjoy your new car and the gas savings that come with it!
     
    #3 Paradox, Jan 2, 2010
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  4. unit333

    unit333 Junior Member

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    Thank you guys for the replies.

    I thought its not a big deal since no warning lights came on but thought I'd check.
    Just to answer the questions, no snow on the road just cold, I have been driving for about 20 min, mostly stop and go, caught like 20 traffic lights, heat was on...thats really it...
    What happens if the battery is completely drained for whatever reason? Does the car stop or does it convert completely to gas until it recharges itself?
     
    #4 unit333, Jan 2, 2010
  5. efusco

    efusco Moderator Emeritus
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    The battery won't ever drain completely unless the car is badly broken, the ICE will run more to charge it up. If it gets very low on, say, a very steep high hill climb and you're trying to go fast you will note a significant loss in power, but the battery will never drain completely.
     
    #5 efusco, Jan 2, 2010
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  6. Paradox

    Paradox Prius Enthusiast / Moderator
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    The battery will never completely drain the car will not allow it.

    The bars on there do not represent a full charge/discharge of the battery anyway. The reason the battery lasts for so many years/miles is the car keeps the battery within a 40% to 70% charge range. The percentages are wrong I'm sure but my point is the battery is never fully discharged nor never fully charged.

    When the bars do get low on the display though it'll just run the engine to recharge it a bit more and then shut the engine down once it reaches a level it likes.
     
    #6 Paradox, Jan 2, 2010
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  7. JimN

    JimN Let the games begin!

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    When stuck in traffic turn the temp down in winter & up in summer. Creeping in tunnel traffic can discharge the battery rather quickly. It's no fun (and irritating) to have the gas engine cycle on & off just to charge up the battery a bit.
     
    #7 JimN, Jan 2, 2010
  8. sciguy125

    sciguy125 Junior Member

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    I've had something similar happen to me during the summer. I started it and the battery was 2 bars from the top. Before I made it out of the parking lot (a couple minutes), it was down to 2 bars. It happened twice, but I wasn't able to figure out what made it happen.
     
    #8 sciguy125, Jan 2, 2010
  9. Frankblack0503

    Frankblack0503 New Member

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    When i drive home & my batt is completely full and i start next morning out of my (warm) garage the battery also goes down in less than a minit. I think that the car takes all the power from the battery to save the fuel on a 'cold' engine.
     
    #9 Frankblack0503, Jan 3, 2010
  10. macdonald

    macdonald New Member

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    I have never seen my battery fully charged, i.e., with a bar showing at the top.
     
    #10 macdonald, Jan 3, 2010
  11. pekinkaid

    pekinkaid Member

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    How many bars is a fully charged battery? I always seem to have room for one more bar at the top of the battery icon.
     
    #11 pekinkaid, Jan 3, 2010
  12. Paradox

    Paradox Prius Enthusiast / Moderator
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    As I mentioned above, a battery indicator on the dash which is fully charged does not represent in reality a battery which is truly fully charged.

    on my 2006 it would often fill up all the bars but on my 2010 it has only done it twice.

    Anyways to answer your question, I think 8 bars is a full display battery icon.
     
    #12 Paradox, Jan 3, 2010
  13. Frankblack0503

    Frankblack0503 New Member

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    'Full' means except one bar 'empty' means 2 bars left and the engine kicks in...
    But it's never really full or empty so the battery reaches a maximum 'lifecycle'
     
    #13 Frankblack0503, Jan 3, 2010
  14. GrumpyCabbie

    GrumpyCabbie Senior Member

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    If you brake down a long hill you will find that the top two bars on the battery will light up. The car won't allow itself to overcharge and will cut off battery charging and just use the friction brakes if needed. Also, if you have a full battery charge (all bars lit up) the car seems to do all it can to reduce the charge - it runs on battery more etc etc.

    I thing I'm right in saying that. It's my experience anyhow.
     
    #14 GrumpyCabbie, Jan 3, 2010
  15. brandonpa

    brandonpa New Member

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    when I first start the car and go it burns through the battery fast despite using the ICE while warming up. It charges quick after the ICE is warm though.
     
    #15 brandonpa, Jan 5, 2010
  16. brad_rules_man

    brad_rules_man Hybrid electric revolutionizer

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    Mine is fluctuating more-so than normal. I feel that the car was already capable of charging and discharging more quickly than gen2, however I could be wrong. Couple that idea with the super-cold weather and it's understandable. :)

    Your not alone!
     
    #16 brad_rules_man, Jan 5, 2010
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