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Possible Hybrid Battery Failure? Help!

Discussion in 'Gen 2 Prius Technical Discussion' started by faith2walk, Dec 2, 2008.

  1. faith2walk

    faith2walk Upgraded again

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    I own a 2005 Package #4. 189k

    i think my hybrid battery is failing!!

    Most of my mileage has been freeway based and usually with a load of equipment (250lbs+, even one load at just under 900lbs!!). With my modified system(see below) I was happy with 45.4 lifetime mpg.

    Recently (last 2 weeks) my mpg has dropped off the chart. Yesterday I was averaging 25-27 MPG!!! Over the course of the last two weeks I have been hard pressed to get better than 38. This morning I ran the kids to the library and couldn't get it above 22. Granted it was 23 degrees F, but I had an engine block heater, and it was mostly downhill.

    My previous job was doing some work as a courier (thus the reason for a prius) and there were times when I would sit for 2+ hours waiting for a job.

    My theory is that because i did so much sitting in the first 150k miles, that the hybrid battery cycled more than most and is nearing its "end of life."

    Any advice? Thoughts?

    -Modified - 17" scion wheels and tires
    -Upgraded audio - Jensen vm9512hd with nav(replaced oem HU with metra kit), kicker components amped with Kicker 450x4, JL Audio 12v3 in separate boxes amped with kicker 1200x2, Stinger battery (sp1000...1200amps dry-cell), sirius sat via audio in, rear seat displays controlled via new HU,
    -BT stiffening plate, mudflaps, hood deflector, weathertech window deflectors, projector fog lamps (replaced oem junk), aux fog projectors (100w), U-haul hitch and connection to homemade utility trailer (allows a vacation trip with family @ better MPG than minivan)
     
  2. Turbogizzmo

    Turbogizzmo New Member

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    I would think it would throw a code.....toyota can test them I believe??
     
  3. brick

    brick Active Member

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    It's entirely possible. It would be useful to keep an eye on battery state of charge for us and report its behavior. Very rapid charge/discharge and lots of charging from the engine seem to be common symptoms of failure. That and the master warning light coming on!

    Of course a replacement (if that's really the problem) will be on your dime due to the miles. Start thinking about whether you wish to go the used route (getting one from a wrecked car) or a new one (expensive).
     
  4. faith2walk

    faith2walk Upgraded again

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    Already been looking at used. Also been looking at per cell options in case only a cell or two are bad.

    No warning lights, no other problems, but this tank is averaging only 28.6 MPG and I know it's not me. I learned how to P&G and have had tanks that averaged just under 700 miles...will be lucky if this one makes it to 275.

    I have not timed the SOC cycles (charge/discharge) but that is a good idea. I will set up some timed runs (normal work routes) and see what it looks like.

    Thanks for your time and advice.
     
  5. Blegate

    Blegate Prius Gen III 2013

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    Disconnect the mini 12 v in the back for 30 minutes and then reconnect. Can't hurt now can it?

    b
     
  6. hobbit

    hobbit Senior Member

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    Sitting isn't a problem, it's a very light load on the hybrid
    battery -- just maintaining the amp or two into the 12V converter,
    and getting periodic runs of 20 or so charging amps when the
    engine cycles to keep it up. Driving and regen-braking is much
    more load, but with the battery management the way it is it should
    be good for a whole lot of that too. A lot of steady-state
    driving is also almost zero battery use, like on the highway,
    so even with a module or two creeping their internal resistance
    up the MPG of that type of driving shouldn't change a whole lot.
    .
    Getting a properly set up scantool on it that can display the
    block voltages, and then placing various loads in and out, is
    probably the most indicative thing a tech can do. I just did
    this in a friend's Classic the other day, in fact, and had her
    force-charge [test 1] and then drive gently while dragging the
    parking brake [test 2] while I eyeballed the voltages on the laptop.
    .
    _H*
     
  7. faith2walk

    faith2walk Upgraded again

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    The reason I thought sitting so long would contribute was because it caused the battery to drain and then kick in the ICE to recharge, often several times before I would be driving again.

    How would disconnecting the 12v for 30 minutes help?

    What kind of scantool would I need to buy to be able to get that kind of information? Would the one being sold here in PriusChat work?

    PS...just got a call back from my local prius tech and he said I should try 3 things, which I will be doing here shortly.. (1) spark plugs (2) clean the throttle body and (3) clean the mass airflow sensor.
     
  8. richard schumacher

    richard schumacher shortbus driver

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    Do the easy two first. No sense pulling the plugs if the first two fix the problem.

    Somewhat related to the throttle plate possibility: who has been changing the oil? and do you check the oil level afterwards?
     
  9. faith2walk

    faith2walk Upgraded again

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    Toyota does recommend a spark plug change every 100k, so at 188K I am close enough that it could be done, but you are right, I will definitely start with the easier ones first.

    I change my own oil and use full synthetic, 0w-20 Mobile1 and I change the oil every 20k, with a filter change midway. FYI, I moved to this schedule after several used oil analyses showed I could. For those interested, my TBN has never been lower than 2.1 at the end of 20k. I generally use just over 3.5 quarts so that the marker shows midway on the oil dipstick after having the ICE run a few minutes. I also add 0.5 quarts after a filter change to compensate.

    PS...the toyota tech told me that for $175 he could check each of the cells (would required complete disassembly) to determine if any were bad, but as has already been mentioned, since no codes have been thrown, he doesn't believe its the hybrid battery.
     
  10. hobbit

    hobbit Senior Member

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    For that $175 the tech would hook up the scantool and tell the
    car to read the voltages, without having to open up the pack or even
    come close to getting dirty. They're feeding you a line there.
    .
    One scantool that can do this is autoenginuity, with the toyota
    enhanced functionality. Around $400 all told, I haven't priced
    it out recently. You supply the laptop. There are others floating
    around too; google for "scantool" and "bi-directional" and
    "manufacturer" which will help ferret out the ones likely to
    have the most functionality where Priuses are concerned. I
    think AE is the most popular and debugged at this point, though.
    .
    _H*
     
  11. faith2walk

    faith2walk Upgraded again

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    I always look to the techs for advice, but as you may already have noticed, I call them first. They do not have the luxury of seeing my car and charging me money until I am absolutely certain I know the problem and I cannot take care of it myself.

    It does not surprise me that I can do it myself, but $175 vs $400 sounds to me like I should have them do it.

    Thanks for the options. I am going to go search now....

    I really like what that autoenginuity product can do, but am not sure I wish to spend that much...are there any others that will offer what I need without that price?
     
  12. David Beale

    David Beale Senior Member

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    Any Toyota dealer should do a test using the scantool for under $100. Even if no codes are there they can read out the module voltages. Note that you can't replace a cell, you replace a module, which is 6V nominal, or 5 cells. The standard charges are around $60 to connect the scantool and standard shop rates for the testing (at $110/hr around here). So perhaps $175 is a reasonable quote. What he said he would do is incorrect.

    If you are currently using the car for short trips (less than 10 min), then the mileage you are seeing is not unusual in winter conditions. Mine currently is down in that area due to short trips and ambient temps around freezing. I'm seeing 40 MPG imperial (around 6 l/100 km). If I drive for 20 min consumption will drop into the low 5 l/100 km right away. After about 40 min of use the consumption average drops into the high 4 l/100 km.
     
  13. spitinuri

    spitinuri Member

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    You seem to have a good understanding of your car.... While you didn't mention it... I assume that you have checked your tire pressure and it is at recommended tire pressure. (I run high 50 psi in front and 48 psi rear. Even in cold weather 20-35 degrees still getting 45-52 mpg.) Plugs are the second best option. Throttle body and max air flow sensor are a little down the line.

    I haven't seen this mentioned in Prius forum but with your mileage you may be having some carbon buildup in your engine. This could cause a pretty nice drop in mpg. If it hasn't been done I would try a decarbonizer and plugs. My guess... you will be good as new.
     
  14. faith2walk

    faith2walk Upgraded again

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    I choose not to run at higher pressures anymore because I ruined a set of Goodyear Tripletreads that way. The warranty on them was 85k and the tire shop had to replace them at 69k...definite wear pattern down the center from higher pressure, so they told me that they would replace them then, but never again if I used such high pressure.

    I generally keep them under 36, but never lower than 33.

    I think you are right...as previously mentioned, going with the plugs and some cleaner.

    Thanks
     
  15. ScottY

    ScottY New Member

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    I have a set of GY Comfortreds. I used to run them at max side wall psi of 41. I started to notice higher wear in the center pretty early on and lowered the pressure back to 35. Now the tires have better traction and even wear pattern.

    [start rant]
    Higher pressure works for one type of tires doesn't mean it works for all tires. PCers should stop recommending higher pressure to everybody.
    [/end rant]
     
  16. spitinuri

    spitinuri Member

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    [start rant]
    Higher pressure works for one type of tires doesn't mean it works for all tires. PCers should stop recommending higher pressure to everybody.
    [/end rant][/quote]

    Rant noted. A closer read might show that higher tire pressure was not recommended. I realize that I am giving something away (breaking distance, smoother ride, handling in wet conditions) by running higher tire pressure. For this reason I would not encourage anything other than recommended tire pressure to anyone.
     
  17. ScottY

    ScottY New Member

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    spitinuri, I didn't mean to target the rant to you. It is a general rant, because in almost every thread related to MPG, I see PCers recommending higher tire pressure without knowing what kind of tires people are using. From evidence provided by some PCers, seems like the OEM GY Integrity do suffer wear from under inflation. Using higher pressure is justified. This condition doesn't apply to all tires.
     
  18. spitinuri

    spitinuri Member

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    No problem. Merry Christmas!
     
  19. txtabby

    txtabby 2011 Prius 4

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    I was wondering about the Traction Battery life span myself. I own a 2007 and I have about 10k left on the warranty. I heard, from a salesperson:rolleyes: , that the replacement would run about $8000! 4 sounds a bit more reasonable... BUT, if they come out with the 'plug-in' Prius, I'm tradin' this baby in! (After a year to work out the bugs, of course:p) I already just love the hell out of my car. A few things I still want to do (upgraded speakers for one) but compared to my 1994 Saturn that I bought NEW 15 years ago, oh wait, there is no comparison. :D

    My mom is thinking of getting a Prius and wants to know more about how long the battery lasts.
     
  20. Celtic Blue

    Celtic Blue New Member

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    You've already put 90k on it? (or 140k if in CA?) The battery has an extra long warranty. Now if I were putting miles on at the rate above I wouldn't sweat it, just factor in replacing the battery at 200k or something like that. Putting on miles that quickly the Prius would be ideal and one would want to run it until multiple systems were failing.

    Since you can buy them for around $2,000 new, this salesperson is either full of it, or trying to mislead you.