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sudden battery discharge

Discussion in 'Gen 2 Prius Main Forum' started by Elizabeth Jones 11, Jun 7, 2008.

  1. rsforkner

    rsforkner Member

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    >> 75F - 77F <<

    WOW! I would have to wear a sweater in there. I almost always set mine at 80.

    Bob
     
  2. removeum

    removeum Member

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    :cool:Remember the traction battery gets it's cooling from the inside the vehicle. If the traction battery gets hot your mpg will really take a hit and it is not good for the battery either.
     
  3. mikemartin9

    mikemartin9 Junior Member

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  4. tom_farr

    tom_farr New Member

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    Don't know if this thread's still alive, but I found it while searching for other victims of sudden discharge. Mine happened this weekend (1/14/11) in the middle of a long trip from LA to SF. Normal operation for most of the trip, but after an hour's stop and then starting up in stop-and-go traffic, I noticed that the gas gauge had suddenly dropped to 2 bars when it should have been more than half full. The engine was constantly on and revving, even when we were stopped. Cool temps and no A/C. I checked the SOC and it was down to 2 bars. We were just getting on to the Bay Bridge, so escape wasn't an option, so at the next traffic stoppage, I turned the car off and back on. (My wife was not amused). That fixed the problem, but it took some time to (re)charge the traction batts. Thankfully the problem hasn't recurred, but with the above, I'm worried. I'll now check the 12v battery to see if that's a problem.

    2005 Prius, ~75k mi.
     
  5. GuamKelly

    GuamKelly Member

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    While it's unlikely the Dealer (or Toyota) will replace the battery or control module until a light appears and a code is set, it's important that you take the car in, report the issue, AND KEEP PAPERWORK showing that you have done so. This would be true for any car, any problem, while under warranty.
     
  6. cwerdna

    cwerdna Senior Member

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    unclear if anything is abnormal

    Yes, check the 12 volt, esp. if you're on the original as it's quite old now.

    As for "gas gauge suddenly dropped", I can't answer on that. Did it "recover" after power cycle?

    As for being down to 2 bars (or even 1) SOC, that's perfectly normal if stopped, in stop and go traffic or stuck in a parking lot and accelerated substantially with the AC on. Want to repro? Just sit in the car w/power (fully) on. Within a say 20 minutes or less, esp. if you decide to creep along and stop and go and use the AC, your SOC will be low.

    As for "engine was constantly on and revving, even when we were stopped", were you using the heater? If the fan speed is above OFF and you have the heat above LO, the ICE could be running to provide cabin heat. Per Monthly Weather Forecast for San Francisco, CA - weather.com, the temp was between 50 F and 59 F that day in SF. It's perfectly reasonable for the ICE to cool down enough in stop and go to need to run to provide requested cabin heat. I've discussed this many times such as at http://priuschat.com/forums/gen-ii-...-going-electric-vehicle-mode.html#post1082689.

    You can try the experiment I mentioned yourself. Set the heat to HI and you can get the ICE to turn on/off at at will by turning the fan on/off w/a cold enough ICE. ScanGauge lets me see FWT and thus I can always repro and know the threshold.

    What I would be concerned about as a sign of a failing HV battery (someone here can chime in to correct me) is if there are huge swings of SOC in a short period of time, esp. if accompanied by the HV battery fan (intake vent is in the back seat area) running at high speed and very large mileage loss (no, not just due to colder weather, under inflated tires, overfilled oil, etc.)
     
  7. hektorr

    hektorr New Member

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    I noticed soc drop form 60 to 37 in 40 seconds. Starting a car in ev mode becasue of downhill. At the end of dowhill while battery was charging itself soc was dropping to 37. What is going on Anybody found a solution for this? Its normal weather here 15 C. Prius is 2005. Noticed this one week ago. Should I visit a dealer? Thank You for replys :
    |)
     
  8. ystasino

    ystasino Active Member

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    Driving a Gen II in the before the initial 50-80s cycle uses huge amounts of charge from the HV battery, does this drop you report occur after the initial cycling (when the ICE has stopped spinning and the car no longer shudders) while you're in D?
     
  9. hektorr

    hektorr New Member

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    Im starting the car and when its in ready i press ev to roll of the hill and while rolling down green arrows showing charging and soc is dropping. When hill is finished (soc is in 39) Im turning ev mode off and then engine is spinning. But all this in 0-30 mph
     
  10. seilerts

    seilerts Battery Curmudgeon

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    How do you monitor SoC? Can you also monitor battery current? Highest and lowest cell block voltages?
     
  11. hektorr

    hektorr New Member

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    I have scangauge and dont know any other devices which are able to do this. Probably its there out somwhere other program for sg to put in.
     
  12. Asmodeus2112

    Asmodeus2112 Junior Member

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    Our 2006 does this too. Two summers ago Toyota replaced the Traction Battaries, then the Transaxle the next year, and now the traction battaries are not holding charge anymore. ~40k on the car. Back to Toyota, time to unload this lemon. :drama:
     
  13. richard schumacher

    richard schumacher shortbus driver

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    Toyota didn't replace anything: one particular dealer replaced things after repeatedly misdiagnosing the problem. Go to another, competent, dealer and find out what's really wrong.

    Do you carry dogs in the back seat? or anything else that might block the battery cooling air inlet or its fan?
     
  14. Asmodeus2112

    Asmodeus2112 Junior Member

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    Your right, the dealer replaced the parts. I'm just frustrated and tired of this...
     
  15. uart

    uart Senior Member

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    Hi Asmodeus2112. Can you let us know what was eventually replaced to fix your problem?

    Also, have you (or the dealer) checked the rear fan as Richard suggested?