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Traction Battery Smell

Discussion in 'Gen 2 Prius Main Forum' started by Gino Veltri, Oct 23, 2021.

  1. Gino Veltri

    Gino Veltri Member

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    How is this not a more common topic on here? Ive had several 05 pri and handled my fair share of burnt out batteries , and they all have this certain smell. Similar to the smell when you provide something with too much voltage and blow it. Electrical plasticy kinda smell, very unique. Thus, also very alarming. Someone recently gave me their dead traction battery and it wreaks like this but nothing appears externally wrong. I wanted to salvage some good modules for my pack that is failing so i have several questions.

    1. When does the battery fan kick on? Is it ok for temperatures to reach 110 degrees? I would think wy fan would kick on before then but i have to use the dr. prius app to override the fan to turn it on. This doesnt seems normal. But its not a fuse or wiring because i can turn the fan on with the app. What gives?

    2. In a similar line of questioning, is it normal for a battery to reach upward of 260 volts when braking or coming down a long hill? The Dr. prius app flashes red and my from what i know (and that's very little) that is a 201 volt battery back there. So what is "overcharging" exactly? and is it related to the burning electrical smell ive come to associate with all pri batteries?

    3. Finally, does anyone know of a cause (other than failing battery module) for a very intermittent (as in a reset it by unplugging the 12 volt) and seemingly unpredictable code P3000 and P0A08. Perhaps related to corrosion on battery fan plug in this area: https://attachments.priuschat.com/attachment-files/2021/02/200806_IMG-b2be2999902a9ffcdb6ff6bfbbce03c9-V.jpg
     
  2. dolj

    dolj Senior Member

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    1. The fan is always on (mostly) however, it is on at such a low setting (up to speed 4, I believe) that it is not audible. You can test it by putting some strands of tissue paper in front of the inlet grill to visualize the airflow. Second thing, if you use Dr. Prius (or any other app) to override the fan control, then the battery ECU can no longer control the fan. So if you are overriding the fan long term you should set it to 6. 110ºF (43ºC) is getting up there. It might be considered unusually high if it was up there and the battery fan was not coming on at a higher speed.
    2. The nominal voltage of the hybrid vehicle battery is 201.6 V i. e. 7.2 V (nominal) x 28 modules. however, this is not the operating range of the battery which is typically 215 - 228 V. The full range of the battery is 202 V - 235 V. In operation it can go higher than that, although I think 260 V is getting to the battery is severely sick territory. The smell could relate to the electrolyte off-gassing due to excessive pressure??
    3. Most likely you have a high voltage electrical leak (P0AA6 - Hybrid Battery Voltage System Isolation Fault). This most likely will be caused by electrolyte physically leaking from around the module and creating an electrical path to ground.
     
  3. ChapmanF

    ChapmanF Senior Member

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    There is probably no one who has investigated the traction battery smell situation more closely than hobbit.

    You might be interested in reading his write-up about it.

    [​IMG]
     
  4. Gino Veltri

    Gino Veltri Member

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    Lol . I love you people.
     
  5. bisco

    bisco cookie crumbler

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    don't forget the vent tube smell...
     
  6. Gino Veltri

    Gino Veltri Member

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    Thanks so much! Yeah theres smoething to the fan thing because battery temps were at 110 and no fan sound. I overiride it with dr prius, but slide it down low to 60 degrees and it blows hard. I put it at 85 (the standard) , or even turn off the override, and i hear nothing. I know i dont want to override the prius brain as Ive gathered it's highly intelligent machine. But thats one aspect id like to, always have the fan blowing full blast, anyone know of a way to do this? There is also corrosion on two of the pins for the fan connector, ive cleaned as best as i can but its still there. (Also, dont unplug this while the car is in ready , prius got mad at that) And i swear I had to unplug and replug this in to turn off the red triangle once...i thinnk

    The Battery regularly reaches 240V -255 (red indicator) when braking hard or going down a long hill with an already full battery. My battery is bad ad ive just been in denial because I was amazed at the job the guy who reconditioned and replaced modules did 2 years ago. It made it over the rockies twice! I also finally got a full battery test complete with Dr.prius (800 seconds!) after a long hard drive, and it said 32 % , it's time...I also watched my wifes much newer toyota battery last night and saw just how tight her voltages are. like almost exact. Mine are all over the place ( does this mean they could be rebalanced? im unsure of how all that works). Also after it gets hot my resistances go up on a few modules....But it drives so well still, the P3000 and P0a80 take so long to appear, like several days and hundreds of miles ( i know this is unsafe to reset them by way of the 12 volt). I also...Ive had a bad 12 volt in there ( i killed it twice leaving the obd in the car overnight, and theyre small lawn n garden batteries). So i wanted to rationalize that this was the cause. So....Does anyone know anyone local to Fort Collins CO, that does reconditioning/rebalancing/rebuilding of packs? This car wont make it another 10 years the way i drive and with its numerous other quirks....i also have a donor battery that has to have a good module or 2 (it was also corroded as hel and threw a P3000 as soon as i tried to drive with it...but all the voltages are very equal). Surely one of the two batteries can be made into one whole.

    3. I certainly dont have electrolytle leaking from the modules , i just took the battery out the other day to try this other bad one, Ive never seen that code or any liquid oozing from my modules
    Now that i dont have to jump it everytime, im going to read the battery before putting it in ready and see if i can pinpoint the bad module/s.
     
  7. Gino Veltri

    Gino Veltri Member

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    .....or not, those damn lawn and garden batteries. Or i might just add parasitic drain to the list of issues im having.
     
  8. Marius27

    Marius27 New Member

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    In the end nobody is saying how to solve the smell problem. I have it also and can`t get rid of it.
     
  9. rogerthat

    rogerthat Active Member

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    As Bisco alluded, are you sure the smell is not from the rubber vent tubes? Seems like the link to that Hobbit write-up also identified the vent tubes as the source of the smell. If so, the fix is easy, simply replace the vent tubes. I did this with mine years ago with silicone tubes and the smell (urine like) was gone within a short time.
     
  10. Marius27

    Marius27 New Member

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    I think also a clean in bus bar terminals is needed. They get corroded and begin to create a smell around them... Oh well, we got some work.
     
  11. ChapmanF

    ChapmanF Senior Member

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    I've never noticed corroded metal terminals smelling like much.

    But there have been prior posts about those vent hoses developing a strong smell, corrected by replacing them.