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signs of weakening traction battery?

Discussion in 'Gen 2 Prius Technical Discussion' started by jmooney, Apr 22, 2012.

  1. jmooney

    jmooney New Member

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    We bought our Prius at 95k miles at a Toyota dealeship about a year and a half ago. I havent reset the mpg in several tanks of gas and am averaging 50.6 mpg. Last night we pulled in to our neighbors drive to look at her dog and sat and chat with the windows down for about 20 minutes. I never turned off the car but the parking lights were on. I noticed the traction battery display only showed 2 bars when we got back on the road. Within about 5 miles, the battery was back up to normal 4/5 full. Again today we pulled in a long line at Mcdonalds. By the time we got through, the battery meter showed slightly less than half full. I've never noticed the car do this in the time we've owned it. Is this normal? I thought it never drained it just sitting in one spot before like this.

    A little history on the car.. When we bought it with 95k miles, the salesman said it was in for a new traction battery and the orig owners just traded up instead of waiting on it so according to him, it had a fresh battery. Whether or not it actually did is up in the air. I suppose I could call Toyota and get a history report for the car?

    Is this nothing to worry about? It just seems to be adjusting faster than ever lately.
     
  2. gmcneil05

    gmcneil05 Member

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    My 05 does the same thing.
     
  3. NortTexSalv04Prius

    NortTexSalv04Prius Active Member

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    I would hook up a scangauge 2 with x gauge and see what your BTV and BTA are before making any other decision or choice
     
  4. bisco

    bisco cookie crumbler

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    they all do that, it's fine.
     
  5. fuzzy1

    fuzzy1 Senior Member

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    Whenever the ignition is on, the various engine and control systems are drawing several hundreds watts of electrical power. This must come from somewhere. If the ICE isn't burning fuel and regenerative braking isn't active, then this power must be drawn from the traction battery, slowing draining it. So the mere fact that your battery meter fell is normal and expected. It is impossible for it to not drain in these situations.

    The rate at which it falls is another matter. But I'm not in position to determine whether the rates you observed are normal, or excessive.
     
  6. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Sounds normal to me. You left the car in 'Ready' mode for 20 mins with lights (and probably heating or a/c on) and then it was on 2 bars when you came back to it?

    Mine would last about 20 minutes like that too.
     
  7. jmooney

    jmooney New Member

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    thank you all for the responses. We really like this car and want to keep it a long time, besides I just put a new set of tires on it and I need at least another 50k before we can even think of selling. Right now we're at 125k. We love the great fuel mileage but I think we've been a little more concerned than normal about maintenance costs after having a light bulb go out (thank you amazon and youtube).
     
  8. Flying White Dutchman

    Flying White Dutchman Senior Member

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    over time the total capacity of the battery pack decreases
    so you will see that things like this will happen faster then before
    and at some point the mpg will drop because the battery will hold less charge
    by then you still would not have any battery failure ( but ofcourse thats possible anyway ) because this is normal with any battery over time.
    if a cell starts to fail or the capacity drops to low that the ice needs to keep running al the time i guess the prius will tell you there is something wroing with the HV battery
     
  9. hectorhicool

    hectorhicool New Member

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    I want yo Know What is happening with my 04 prius, have about 185k miles and i dont use it about 2 years, the backup battery was changed it began to turn on the red triangle and the check engine, yellow brake ligths. Then when i run the car several miles the traction battery charges very low when it charges about three lines, i turn off the power and when i turn on the yellow brake light turns off, but the red triangle and check engine keep on. Then when i run several miles after its go to normal. I want to know whats damaged, the traction battery or the ECU battery control or need a programming upgrade...
     
  10. bisco

    bisco cookie crumbler

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    :welcome: 2 years is a long time to store a hybrid. i think you need to get it to a dealer or experienced hybrid mechanic for a full check and code reading. all the best!
     
  11. jmooney

    jmooney New Member

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    you might want to start a new thread so more people can see what you are asking. Its not a good idea to let a prius sit for two years though.
     
  12. GSW

    GSW PRIUS POWER

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    jmooney, it sounds normal. On another subject, but highly important, you might want to have your transaxle fluid drained and replaced if you haven't had it checked. Especially after 125K miles.