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HV Battery Temps Hitting 116f

Discussion in 'Gen 3 Prius Technical Discussion' started by priusCpilot, Aug 15, 2017.

  1. priusCpilot

    priusCpilot Active Member

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    I have a Prius C. Outside temps can hit 100+ and after parking the batter temps can be 116. Even parked in the shade? Also in stop and go driving they go high 110 and drop slowly? Temps are from the center probe on shown on a SG.

    I started to put the battery on speed 6 now. I know others have the same temps but don't know it since they don't have a SG under the same conditions.
     
  2. bisco

    bisco cookie crumbler

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    a/c on full blast?
     
  3. priusCpilot

    priusCpilot Active Member

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    Yes I do drive with the AC on and also I said it for middle and lower events so that down some cool air goes down below to where the event is to the battery.
     
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  4. davecook89t

    davecook89t Senior Member

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    116 F? Pshaw, that's nothing. 58.4 C (137 F) Temp on HV Battery per Torque Pro | PriusChat

    More than 5,000 miles later, my car still runs like a top. As @edthefox5 said, these are tough little cars.
     
  5. bisco

    bisco cookie crumbler

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    the do suffer in the south though. unfortunately, it's not when you're driving as much as it is the heat soak of parking in the sun all day. great for solar panels though.
     
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  6. priusCpilot

    priusCpilot Active Member

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    Wow never went that high. I did see 122 which came down to normal levels after parked.

    Now I run the fan speed 6 full time. I like keeping it as cool as possible because shortens battery life.
     
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  7. davecook89t

    davecook89t Senior Member

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    I feel the same way, I would like to keep it as cool as possible. I understand the fan speed can be controlled using a Scan Gauge, but I do not believe it can be done with my Torque Pro app. In any event, it is comforting to know that the battery will survive the occasional overheat incident.
     
  8. bisco

    bisco cookie crumbler

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    makes you wonder why toyota doesn't have the fan speeds come on at lower thresholds.
     
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  9. davecook89t

    davecook89t Senior Member

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    Maybe running at a lower fan speed saves a fraction of an MPG? I'm learning to trust the judgement of the folks who designed the car, but sometimes I think I would have made the safer choice.
     
  10. bisco

    bisco cookie crumbler

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    they have to pony up for the 10/150 warranty, but not in too many hot states.
     
  11. davecook89t

    davecook89t Senior Member

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    You're saying they might have had a different design strategy if more southern states had adopted the CARB standard? Interesting.
     
  12. bisco

    bisco cookie crumbler

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    it's possible. the whole southern border is non carb, and most all the the central states. so they only have to worry about socal.
     
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  13. davecook89t

    davecook89t Senior Member

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    And unlike the East Coast and South, night-time summer temperatures are generally much more tolerable even in Southern California, so the battery has some chance to cool off.
     
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  14. priusCpilot

    priusCpilot Active Member

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    I thought the same? The only conclusion I came up with were these?

    1.) Fan noise might annoy a hybrid owner?

    2.) To get a tiny bit more MPG but when the bat runs real hot MPG falls?

    3.) Premature fan wear that may fail during warranty which might be more of a risk compared to battery??


    Anyhow, all three are not an issue for me. Prolonging battery life in hot climate is my top priority.

    I have no pets and have 90k miles. Wounder how dirty the fan might be?
     
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  15. bisco

    bisco cookie crumbler

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    probably not very, but worth a look when you have a chance. check the intake grille, that's easy.
     
  16. William Redoubt

    William Redoubt Senior Member

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    Check out this thread. 240 degrees!!! | PriusChat

    116 degrees is well within the expected range for normal operation.
     
  17. priusCpilot

    priusCpilot Active Member

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    Thanks! This thread is for mg2 temps which I have seen 270f while towing my jetski. I'm not concerned with that as much as battery temps. I also switch to Redline oil in the trans to protect it further since it retains very good viscosity under high heat.
     
  18. priusCpilot

    priusCpilot Active Member

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    Running the fan on high has done the job. The bat now runs in the 90s with AC on and hot ambient temps.
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

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    Is it possible you're over cooling?

    Driving on cool evenings with windows half rolled down and monitoring the middle (hottest) battery sensor, ive seen 35C. This would seem to be by design, Toyota's ok with this.
     
  20. priusCpilot

    priusCpilot Active Member

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    No not in Summer that's for sure. Today it is 110f. When it cools down for no AC I'll turn off the fan.

    So far from the middle sensor I can seen 122F but no more.

    Here is why I think Toyota is OK with the higher temps.

    1.) Fan noise might annoy a hybrid owner?

    2.) To get a tiny bit more MPG but when the bat runs real hot MPG falls?

    3.) Premature fan wear that may fail during warranty which might be more of a risk compared to battery??

    The high temps will not kill the battery immediately. It will make it threw threw warranty but will shorten the life. I plan on going at least to 300+k miles without replacing the bat. I'll have to see how the fan looks some time next year. Also going to install a tool to balance the cells.
     
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