1. Austin Longenecker

    Austin Longenecker Junior Member

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    I'm on a 1,800 mile road trip over the next 2 weeks and today was my first leg of the journey. Today I covered a near 600 mile trek, and after the 300 mile mark, my mpg suddenly fell from 50 to 27 mpg. The battery does not seem kick in during acceleration or coasting at high speed and will only operate when coasting below 40 mph. I have never had any issues like this before and this is my first time seeing low mpgs. Has anyone experienced anything similar and/or know why this happens?

    The battery will operate like normal in EV mode for as long as it usually would, but in eco, normal, or pwr mode, it seems as if the battery has forgotten its job. Any advice? Is it safe to finish the next leg of my trip? I will drive another 600 tomorrow then I wait a week to finish the last 600.
     
  2. Austin Longenecker

    Austin Longenecker Junior Member

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    I have no warning lights of any kind and I checked all my fluids and tire pressures before leaving this morning.
     
  3. bisco

    bisco cookie crumbler

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    tough call, how many miles on her?
     
  4. Austin Longenecker

    Austin Longenecker Junior Member

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  5. bisco

    bisco cookie crumbler

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    have you ever cleaned the egr circuit?
     
  6. Austin Longenecker

    Austin Longenecker Junior Member

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    Cleaned parts of it and had the rest of it completely replaced not even a year ago.
     
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  7. Austin Longenecker

    Austin Longenecker Junior Member

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    I've also made sure that nothing is blocking the battery air vent. I was expecting lower than normal mpg due to the weight if my luggage, and was surprised at my 50 mpg still. Then as I passed the TX/OK boarder at 300 miles into my trip, it dropped nearly 50% in minutes. The trip mpg dropped to mid thirties and was still falling as I pulled into my hotel for the night.
     
  8. bisco

    bisco cookie crumbler

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    edit:
    have you cleaned the battery cooling fan?
     
  9. Austin Longenecker

    Austin Longenecker Junior Member

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    I have not. Is that something I can do easily while out of town? I thought about that but didn't think it would explain the abruptness of it. It's as if the computer said "welp, battery needs a vacation."
     
  10. bisco

    bisco cookie crumbler

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    that's a good point. i suppose it can get dirtier and dirtier, until it causes a problem, but you would think you'd get a dash warning.
    there should be a youtube video on cleaning it, but that may not be the problem.

    i suppose you could have a weakening cell that hasn't thrown a code yet, but no way to know without a scanner.
    or maybe some corrosion inside the battery.

    is it hot out?
     
  11. Austin Longenecker

    Austin Longenecker Junior Member

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    I live in central texas. It's been getting 127° F in the sun this last week, but I park my car in a garage where its probably mid to high 80's. On this trip today, as I travel up north, it's been mid 90's.

    Wouldn't a weakening cell mean the EV mode would be effected as well? EV works as well as normal, until I accelerate fast enough that the ICE needs to kick in, where it seems as if it completely runs on ICE alone.
     
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  12. Grit

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    HV battery could have gone into some protection mode because of heat disabling charge and discharge of the HV battery, did you run AC on at higher speeds?
     
  13. Austin Longenecker

    Austin Longenecker Junior Member

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    I kept the ac at 72°F, and occasionally turned it to low speed fan only to see if there was any increase in mpg both before and after the sudden drop. After the drop it made no difference at all, but when everything was working normally, it did make a slight difference.
     
  14. Austin Longenecker

    Austin Longenecker Junior Member

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    tonight will be in the mid 70's so I'll see what happens after a night of cooldown. Hopefully it not an expensive failure. Can't really afford that while I'm moving out of state for university.
     
  15. JC91006

    JC91006 Senior Member

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    I have 120k miles on my 2010 with 17 inch wheels. This summer I'm getting around 35mpg because the battery has weakened significantly and it's not doing much anymore. I'm just waiting for it to die.
     
  16. Austin Longenecker

    Austin Longenecker Junior Member

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    That's why I've been keeping my car in our garage, because I knew how hot Texas summers are and how bad that can be for a battery. I cant afford a new one!
     
  17. Grit

    Grit Senior Member

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    It can take couple of hours For Hv bat to get back down to regular temperature even if ac is on at high. hv intake fan turns on at 96F at speed 1, which is why It will take hours to cool down battery. I just go with speed 6 and cold rushes into the pack, helps cool down very fast
     
    #17 Grit, Aug 13, 2019
    Last edited: Aug 13, 2019
  18. Austin Longenecker

    Austin Longenecker Junior Member

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    I'll see what it does tomorrow morning. It was a 9 hour drive, 4.5 of which the battery did not seem to work properly.
     
  19. fuzzy1

    fuzzy1 Senior Member

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    Did you leave the AC on its default Recirculate mode? Consider switching it to fresh outside air. Though this will make the AC work harder because it is taking in hotter outside air instead of cooler inside air, it will also force more cooled cabin air through the battery. If the battery is having an over-temperature issue in these weather conditions, then this extra cabin air ought to help cool it. It will take a while to do any good.
     
  20. Austin Longenecker

    Austin Longenecker Junior Member

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    I switched between the two. I've had problems where if I leave it in the sun too long the AC and radio overheat and won't turn on until the system have cooled, but that's only happened after leaving my black car sitting in the summer sun for many hours. Even then, when the cabin was 150°+ (hot enough to overheat an external thermometer) the battery worked fine. The cabin was 72° yesterday when it stopped working properly. All other electronics worked as normal. I'll leave here in a few hours and give an update if anything has changed after letting my vehicle cool down for a night.
     
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