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Please help with battery temperature or battery fan

Discussion in 'Gen 2 Prius Main Forum' started by Brando714, Jun 8, 2020.

  1. Brando714

    Brando714 Member

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    So I cleaned my battery cooling fan and put it all back together. I noticed some corrosion on the harness, but it must've been there already since I bought the car a week ago and the cooling fan was working fine. Ever since I took it off to clean it, I have not heard the fan come on. I never dropped the fan, never got it wet, just cleaned it with Q-tip and air duster. I double checked to make sure both harness were plugged in all the way. After a test drive on the freeway of 12 miles, I got home and my battery temperature quit fluctuating but eventually hit the 120F mark that was colored red on Dr Prius. What is going on? It was a relatively easy just to do so I highly doubt I messed anything up but like I said, the fan was working cause I kept hearing it in the back passenger side.
     

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  2. TMR-JWAP

    TMR-JWAP Senior Member

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    So question #1 is: Was the fan dirty? Was it clogged?

    When you hear the fan running, that's abnormal. It means the fan is trying very hard to get enough airflow to cool the battery. That can be caused by high ambient temperatures or by low airflow (like if the fan had a lot of buildup in it).

    The fan normally runs at speed 1 or 2, which is very difficult to hear, but is enough to provide adequate airflow to keep the battery at a nominal temperature.
     
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  3. davecook89t

    davecook89t Senior Member

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    Do you know what temperatures the sensors were showing when you did hear the fan? 120 F is not necessarily a cause for alarm. The fan may still be running at a lower level. There is a gauge in Torque Pro that shows the level (1-6) of fan speed, if you want to confirm it is running. Keeping the cabin temperature cool by using A/C will keep the battery temperatures lower. I have never heard the battery fan in our Gen 2 running except on one occasion when Torque Pro showed the middle sensor at 137 F. At that point, Torque Pro showed the fan speed at Level 6. That was 3 years ago. Our battery appears to have survived that one incident intact.

    58.4 C (137 F) Temp on HV Battery per Torque Pro | PriusChat
     
  4. Brando714

    Brando714 Member

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    Yes the fan was EXTREMELY dirty. Dust and hair
     

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  5. Brando714

    Brando714 Member

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    Had no idea what the temperatures were before I cleaned it. I do regret not checking as I did download TorquePro beforehand. Thanks for the heads up on being able to check fan speed on TorquePro, I will go check now
     
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  6. Brando714

    Brando714 Member

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    Hey thank you. I just checked with Torque Pro and it shows speed 5.0.
     
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  7. Brando714

    Brando714 Member

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    Hey thanks a lot. When I first purchased the 2004, I heard the battery kick on loud so I thought that was the norm. When I took it off to clean, it was extremely dirty with lint and hair. I had no idea it was supposed to be quiet and subtle until I read your comment. I put my ear next to the rear passenger vent and yes indeed I can hear it, although very quiet. I was stressing out that I had done some damage to the harness after reinstalling it. Thanks a bunch, made my day as all the stress is lifted off my shoulder... for now Lol
     
  8. davecook89t

    davecook89t Senior Member

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    That's not as bad as some I've seen posted on here. Is that still the original battery in your car? Although occasional temperatures of 120 F should not kill your battery, its life will be reduced if it is continually subjected to temperatures that high. @SFO has a method in his signature for keeping the fan running at maximum speed all the time to (in theory) extend battery life. Generally, when you see high temperatures in your battery's sensors during charging it means the battery is not as efficient at capturing electrical energy as it once was, in other words it is getting "tired", as some describe it. If that battery is still original, after 16 years, that is to be expected. If it was replaced, especially with one that was described as refurbished and not new, it could be a sign that it will soon start giving you problems.

    All the best, anyway.
     
  9. PriusCamper

    PriusCamper Senior Member

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    Looks like you got this figured out... And looks like you know how to use Torque app and Dr. Prius app... So I'll add to that by saying try using the Hybrid Assistant app. When I do diagnostic on fan circuitry I use that app because it allows you to control fan speed better than other apps. The system is slow and clunky in general, but that app will be the easiest way to confirm your battery cooling fan is able to work at full speed.
     
  10. Brando714

    Brando714 Member

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    Not too sure on the hybrid battery pack being the original or not. Today I drove 25 miles in California's 90F weather with AC on low and battery temp reached 130F towards the end but fan speed was at 5 and not the max 6 for some reason
     
  11. Brando714

    Brando714 Member

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    Ok I will download that app right now. I'm still not too sure on how to use Dr Prius and Torque Pro (I have both the paid version) I wouldn't be able to set the fan speed with neither of the 2 apps?
     
  12. PriusCamper

    PriusCamper Senior Member

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    I never had a good experience with Torque Pro... And Hybrid Assistant has some value via it's companion app Hybrid Reporter, as well as it's fan speed controller, but Dr. Prius app is by far the best because it takes what you need Techstream for and simplifies it for easy diagnostics. Eventually I'll get techstream software functioning via a Mini-VCI but have been able to work on Prius for years without needing to use it yet.