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Battery Vent Odor

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by campbellmike, Jul 26, 2014.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    These other Prius you drove (and noted smells) were used? I'm guessing this is something that builds over time, maybe with some material deteriorating.
     
    #21 Mendel Leisk, Jul 27, 2014
    Last edited: Jul 27, 2014
  2. campbellmike

    campbellmike New Member

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    Yes, they were used. All 2008's.
     
  3. bisco

    bisco cookie crumbler

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    my daughter has my old '08 with close to a hundred thousand. never had any odors, i wonder if it's affected by climate?
     
  4. campbellmike

    campbellmike New Member

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    I'm curious about that too. This time of year we see 90+ temp and humidity.

    I also wonder if the smell is more noticeable when the car sits closed up. This car was owned by an elderly person and was only driven 2,000 miles in the past 7 months.
     
  5. bisco

    bisco cookie crumbler

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    well there's the cause of the smell right there. you got the o without the b!:cool:
     
  6. ive

    ive Member

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    Mine does the same. Toyota Germany told me that it is casued by the spare wheel. This is rubbish. It is the battery vent lines. The rubber stinks. There are two fixes for the issue. First, open the hybrid battery and remove the rubber hose. Some replace it with PVC-tubing and t-pieces, others just use no vent lines at all. No one has ever reported something coming out of the vent lines. Not even with balooned and fried cells.
    The second method is mostly removing the smell, but not totally. The battery is vented via a black plastic duct behind the right trunk cover. Ths black vent channel ends about 2" BEFORE a vent hole in the fender. All the vent air including the smell is actually vented into the trunk/cabin. here is also a small hole in that vent channel. Me and others have put duct tape around the hole and used it to connect the vent duct to its exit. No all the smell emanates to the outside. Sometimes in summer you now smell this cow or horse stable smell when you approach the car. On the inside it is almost gone.

    "Kuhstall"-Geruch im Innenraum des P2 - gelöst! - PRIUSforum

    page 5 shows the nduct mod, page 6 the PVC piping. It is all in german, but the pictures speak for themself.

    it is ridiculous Toyota denies the problem. I have told Toyota Germany I'll remove the pipes myself and send their general manager a piece of the stinky pipe. The other pieces will go the car press and car TV shows.
     
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  7. campbellmike

    campbellmike New Member

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    Thanks ive. This appears to be the source of my issue. It looks like the first hole allows air to flow over the 12 volt battery and the second hole allows some of it to exit the car. Toyota likely didn't anticipate the traction battery vent lines creating odors (at least in some environments) so some of that air enters the cabin of the car. I'm not sure why they thought the exhaust/warm air moving over the 12 volt battery was needed as it's only provided when the fan is running. I'm going to see if I can insulate the cover or put some charcoal filter material on the back side of the cover to possibly absorb the odor. I hate to do away with the air flow to the 12 volt as I don't know the engineer's intention.
     
  8. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    I've owned 3 Prius and have never detected a "weird" smell. So to your detailer and the mechanic shop, all Prius don't smell like that. If there is a bad smell in yours, its not from the design, there's likely a dead animal somewhere in it. And please don't block off any ventilations.
     
  9. jdcollins5

    jdcollins5 Senior Member

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    The cooling air is pulled in from the cabin through the rear seat vent and blown through the HV battery to cool the HV battery . The warm air is exhausted in to the 12V battery well because the external exhaust "door" is located on the other side of the battery.
     
  10. campbellmike

    campbellmike New Member

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    My detailer actually told me all Prius smell like this and he can't do anything about it.

    The exhaust door is attached to the vent but the vent has holes in it in the 12 volt battery well. Why?

    If you're Prius doesn't smell that's great but there are plenty of folks who have confirmed they have "the" odor and it's origin. In particular, the post referenced more than once above titled "Prius smell solved!". Here's another one which has a pretty good description:
    What is that smell??? - Toyota Nation Forum : Toyota Car and Truck Forums

    I'll look in the duct work for a rotting carcass but I'm 56 years old, I've smelled a few dead animals during my life including mice hidden for months in unreachable spaces. To my experienced but not formally trained olfactory senses this is not a dead animal smell. I do hope I find a dead something.

    In the meantime, I don't intend to block any air passage as I need the car to last. In fact, I could probably get used to the smell and ignore it. My wife may not be able to do the same as she is sensitive to odor and will be the primary driver.
     
    #30 campbellmike, Jul 28, 2014
    Last edited: Jul 28, 2014
  11. ive

    ive Member

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    you don't block the air flow from the main battery. You just vent it to the outside instead of the inside of the car. AGM 12V batteries are sealed as a design feature. There is nothing to vent anyhow. Being charged by a whopping 3.5A and doing nothing except powering the ECUs for a few seconds per trip, they won't turn hot either.
     
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  12. bisco

    bisco cookie crumbler

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    how many pri have you sniffed? i've had 3 and 2 hycam's and never any odors. don't believe everything you read on the internets, and don't believe detailers and body shoppes. then again, if it's your climate, maybe they do all smell.:unsure:
     
    #32 bisco, Jul 28, 2014
    Last edited: Jul 28, 2014
  13. Britprius

    Britprius Senior Member

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    Unfortunately the Prius 12 volt battery is not charged at 3.5 amps "although the battery is clearly labeled maximum charge rate 4.5 amps". It can and is charged at anything up to 60 amps and beyond depending on it's level of discharge. This is possibly the reason the OEM battery does not last long after a couple of deep discharges.
    This also may be the reason for the airflow directed over the battery.

    John (Britprius)
     
  14. ive

    ive Member

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    I have now received a piece of the stinky rubber pipe and will analize it. My current suspect is para-cresol. It is developed when urine decomposes and is the main odor of swine and horse stables. If you would add a bit of ammonia it would actually smell like urine. How does is get into the rubber? Simple, p-cresol is a chemical that is used to manufacture rubber additives, specifically anitoxidants. It keeps the rubber elastic despite NOx, light or ozone in the air. Otherwise it would crack like to outside of an old tire.

    Once I have run some GC-MS and compare the results with the pure reference compound, I know more. Will be January or Feb, though. No time in the moment.

    PS I have removed the duct tape on the vent to "enable" the battvery vent air to enter the cabin again. Reason was that I tried to get Toyota to fix it through the 8 yr Hybrid component warranty. The dealer had to inspect it. With every drive the smell got stronger and stronger again. Warranty was refused by Toyota Germany BTW. A swap would cost about $1000. I'll rip them out next spring myself. p-cresol is very smelly and classified as a toxic chemical. Good thing is that you can smell it in minute concentrations well below toxic threshold concentrations.


    iPad ?
     
    Battery driven and uart like this.
  15. dadofahusky

    dadofahusky Junior Member

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    Did you ever analyze it? I too am dealing with the smell. Just tried duct tape and will see if it helped over time
     
  16. ive

    ive Member

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    not yet, will have time in January.


    iPad ?
     
  17. uart

    uart Senior Member

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    That's complete nonsense. Millions of people own a gen2 Prius and only a handful report this odour problem. My 2005 prius has done 230,000 km and I've never noticed it the whole time I've owned it, not even once. I've driven in other Priuses too, and never noticed it there either.

    If the ratio of people who complain about it to people who don't complain about it (on this forum) is anything to go by then I'd say it's something like 1 case in 1000. Now I don't know what the detailers definition of "all Prius" is, but for me one in one thousand is a whole other thing.
     
    #37 uart, Nov 28, 2014
    Last edited: Nov 29, 2014
  18. Aaron Vitolins

    Aaron Vitolins Senior Member

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    I have a very sensitive nose, trust me this isn't normal. Even If I bring my nose to the HV battery vent, there's no odd smell, heck there isn't even a smell
     
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  19. uart

    uart Senior Member

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    Hi ive, I first noticed this peculiarity with the HV battery duct several years ago, when I first released that I needed to clean the blower fan (mine was fairly well clogged and my battery was running too warm). My first instinct was to do exactly what you have done, to duct tape it in such a way as to complete the duct all the way to the wheel arch exit, instead of having it exit prematurely as is the case with the stock ductwork. (This was back in summer 2009/2010 btw.)

    I expected that this would improve the cooling of the HV battery, but after several weeks of testing I found no improvement. So I removed my duct tape modifications after just a few weeks. (Remember that I don't have the odour problem, so this was just an attempt to improve HV battery cooling). At first it really puzzled me as to why the stock ductwork was done that way, but as I was removing my modifications the reason finally stuck me.

    That duct opens into a small enclosed air space where the 12V battery is located. Now as long as all the panels are correctly in place in the rear compartment there is really nowhere else for that air to go but out through the wheel arch vents anyway. By opening up the duct before it reaches the wheel arch vents it allows the venturi effect from that vent to pull out heat from BOTH the HV battery and the 12 volt battery. As long as the car is in motion there should be a negative pressure in that air space and so all the hot air from the HV battery should exit the wheel arch vents, regardless of whether the duct has that premature opening or not. This is consistent with my finding that the cooling was not at all improved by modifying that duct work. It is now my firm believe that the Toyota engineers did it that way for a good reason.

    Remember however that I'm talking purely from a a point of view of cooling efficiency, not from the point of view of minimising some objectionable odour. Your case may be different in that even a tiny amount of air escaping from what I've called "the enclosed space" could significantly affect the odour problem, but would have negligible impact on the cooling efficiency.
     
    #39 uart, Nov 28, 2014
    Last edited: Nov 28, 2014
  20. edthefox5

    edthefox5 Senior Member

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    To kelp alieve your fears As a comparison my 07 does not have any smell coming out of the Hybrid vent. In fact I am quite sensitive to bad smells and even maintain the AC system at least once a year by getting under the car and cleaning the e coil under the dash to prevent mold buildup and bad smell.

    There have been a few reports of battery smells I have seen over the last 8 years here but not alot. The prius does not smell at the volume your detail shop reports or it would literally be the death knell for the car. Instead its a very popular car.

    If the vent smells you have something going on in the HV battery case. Given the age of the car and its extremely low miles which reflect the car has sat for extended periods it seems reasonable that possibly one or more of the hybrid battery modules are leaking electrolyte which tends to smell pretty bad like a metallic smell. A very unique smell. Your next move should be disassemble of the vent system to the HV case which is quite easy and put your nose right at the intake to the case. If its stinky there you need to take the battery case cover off and see whats going on
    in there. Smell out of that case I can almost guarantee you have leaky modules which would require a new Hybrid Battery.

    I believe your HV battery car is still under the Hybrid Battery 8/100,000 mile warranty. Which means if any fault found in the case you get a brand new Hybrid Battery no charge. The dealer may fight you on the smell though so may have to pay out of pocket on a battery case inspection which if fault found would be refunded.

    Go to any Toyota dealer and have them look at the VIN and see if there was ever any issue with the HV battery. Or You can do that yourself by joining Toyota.com/owners and put your vin in and it will report any service activity at any Toyota dealer in the US.

    I would not be surprised to find the car came in with that complaint and dealer found no issue and car was traded in. I suspect you bought the car at a dealer.

    The car should have no unique or bad smells.