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Hybrid Battery Temperature

Discussion in 'Gen 3 Prius Technical Discussion' started by AnneN, Sep 2, 2024.

  1. AnneN

    AnneN Junior Member

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    I've recently been monitoring my hybrid battery using Hybrid Assistant and Dr Prius.
    According to Dr Prius the hybrid battery life expectancy is 84% - it is a 2013 Japanese import.
    I have had no warning lights on my dash. Using the OBD scanner no faults are detected but I don't trust the scanner as I don't think it works well on the imported car - I have ordered a Ancel JP700 JOBD OBD2.

    After hearing the hybrid battery cooling fan coming on recently I started using Hybrid Assistant to look at the temps and it does seem hotter than I would have expected - I live in Ireland and the air temp is very cool compared to most other countries. The screenshot (taken just after I turned car off after a 25 min drive on a non congested road) shows the outside temp is 18c (64f), inside car is 23c (73f) with the hybrid battery at 40c (104f) with the fan running on max. Is the battery unusually hot? I have the settings for the fan set at Max 35c (95f) and Min 20c (68f).

    I cleaned the battery fan out last year but just to be certain I took it out again yesterday and it is very clean.

    I also got my 12v battery checked today - I know the voltages are fine 12.8v when off and between 13.5 - 14.4v when on, but with professional equipment they used to check it he said that it was at a higher capacity than it should be - battery is marked as CCA 295A but he said it is showing 445A on the machine - I hope this makes sense? I tried to find out how this is possible but I don't think he knew and wasn't used to a woman trying to dig deeper so I left confused!

    I would appreciated your thoughts/advice on this as I know heat is the killer of hybrid batteries and I'd like to head off any potential problems. I love the car and want to keep it going for many years.

    Thank you.

    Dr Prius.jpeg
     
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  2. Tombukt2

    Tombukt2 Senior Member

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    Dang I can't wait to hear some reasonable answers to this because 104° seems awfully mild temperature-wise even for a battery I mean for a human that's very bad granted but for running things like a fan motor or various and sundry other things even the 12 volt battery if the lights are on and the alternators charging it is going to run close to that 100° especially if it's 100° outside or close to it You granted have lower outside temps and on the attempt of 73° in the car but the batteries enclosed and all of that so I would expect it to be able to go up about 30° above your ambient air temperature I would think but I guess this could be bad I don't see how you're going to get it much cooler I never really look at mine I figure if it's around human body temperature to high human body temperature must be okay I'm wondering what the electric car batteries are running at that have all the fancy cooling and plumbing and all of that I imagine they must hit around a hundred 102 something as large as they are the big mass and the density.
     
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  3. bisco

    bisco cookie crumbler

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    i can't answer for the cca reading, but if the car is making 'ready' i can't see it as a problem.
    you might want to open the battery case and see if there is any corrosion or clogging from debris.
    and make sure the fan inlet grille is clear.
     
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  4. BiomedO1

    BiomedO1 Senior Member

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    Nothing to worry about @ 40c, that's a cool winters' night in Arizona. :D

    Seriously, I got my cabin temperature set for 20c (68f) when it's cool outside. Cabin is set for 25c when it's 38c+ outside, mainly to ease the strain on the AC unit and conserve power. The traction battery is cooled by the cabin air flow, so the cooler the cabin the better. 40c is normal and well within the batteries operating parameters.

    Hope this helps..
     
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  5. MAX2

    MAX2 Member

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    A static picture will not explain anything.
    Hybrid Assistant allows you to take temperature readings in dynamics.
    Then you can analyze how quickly the high-voltage battery heats up depending on the discharge and discharge modes.
    I assume that the internal resistance of the battery modules is high, which is why the modules physically heat up.
    Dr. Prius can show the value of the internal resistance of a pair of modules.
    What is the value on your high-voltage battery?
     
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  6. burebista

    burebista Active Member

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    A 200+ miles trip last week starting at 19°C outside and ending at 34°C.
    You're fine I'd say. :)
    Screenshot_20240903_082511.jpg
     
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  7. MAX2

    MAX2 Member

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    Pay attention to the engine temperature. I don't like high spikes up to 116 degrees Celsius.
    This could be two things. A bad water pump and a bad EGR. High temperatures can cause a blown head gasket, coolant leaks, damaged cylinders, and engine damage.
     
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  8. burebista

    burebista Active Member

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    Yeah, I saw those. Now and then I see those spikes but I hope that's a fluke in reading sensors.
    For example this is from the same trip days later coming home.

    Screenshot_20240903_084714.jpg
     
  9. MAX2

    MAX2 Member

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    Ok. If it's just a temporary glitch in the Android software, then it's fine.
     
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  10. burebista

    burebista Active Member

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    Two years ago I did a half job cleaning EGR circuit. Only intake manifold, EGR pipe and changed PCV valve. EGR flow is now in 14-15.xx range.
    In Torque I monitor water pump now and then and it shows a steady 3500 RPM.
    Coolant is steady too.
    Only problem I have is oil. It starts to disappear. Changing it at 6k miles and during changes I need another 1-1.5 quart.
    Now I want to change traction battery but oil consumption holds me back.
    I really like the car so I want to take care of it.

    Sorry for hijacking thread @AnneN.:(
     
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  11. AnneN

    AnneN Junior Member

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    I'm very cautious of going near the hybrid battery but I would like to take a look to see if there is any corrosion or debris. I assume I need to pull the large orange plug before I do anything else? Does the 12V need to be disconnected?
    Thanks.
     
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  12. AnneN

    AnneN Junior Member

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    Thank you. Reassurance is good!
     
  13. AnneN

    AnneN Junior Member

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    I will get better data from Dr Prius and Hybrid Assistant, I'm getting used to using them. There is so much information but I do like finding out as much as I can about something. Hopefully I'll get some more info to post soon.
    Thank you.
     
  14. AnneN

    AnneN Junior Member

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    No problem. It's all really good information and I''m learning from it. I just checked my graph from the trip last week where I thought it was over heating and it all appears good, no spikes! I need to do a longer drive to get more data but I'm less worried now.
    How do you measure the EGR flow?
     
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  15. burebista

    burebista Active Member

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  16. Tombukt2

    Tombukt2 Senior Member

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    If this is a generation 3 car your battery is pretty old just by the age of the generation 3 itself so it's probably time to pull the orange plug take the top of the battery off and look at the one side under the black covers and see all the black bus bars that should be copper colored like copper pipe and all the videos on Facebook for the plumbing stuff copper not black All of that is adding to resistance then you see the frosted nuts that look like they have cancer growing on them All of that stuff can be removed and if you have a kid that has a rock tumbler buy you some abrasive media throw the bus bars in the nuts in the rock tumbler for an hour wash them and kerosene or Stoddard solution and reuse or buy new that in itself goes a long way for moving electricity around all those modules If you catch it early on and do what you're supposed to do You can get another while out of that set up that you're running If not then you need to do the battery dance or replacement.
     
  17. bisco

    bisco cookie crumbler

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    it's a lot of work to get down to the battery. this video shows how it is done, but he doesn't remove the cover while it is in the car. i think it is best left to a pro.

    watch
     
  18. BiomedO1

    BiomedO1 Senior Member

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    DC voltages below 50VDC won't hurt you. This means that you don't have to disconnect the 12V battery.
    If you do remove the traction battery cover, may I suggest you use the 'one hand method'. The theory goes that when your only using one hand/arm - there's no way of completing the circuit. If you lean or rest other appendages against the car, make sure there's a good deal of insulation in between - again so you can't complete the circuit.

    Hope this helps....
     
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