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Lost 10mpg after EGR clean, etc. Now losing mind!

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by FriedCells, Oct 12, 2020.

  1. Grit

    Grit Senior Member

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    Now that I'm done reading the original post and all the replies, I would check your 12v battery health. Yes I know it was changed 132K miles, but it may not be able to hold a near to full charge anymore. As we know, 12v battery can crap out and stop working around 3 to 5 years. Even if it's a yellow top, or any brand, it could go bad sooner than the 3 to 5 years expired date. I once left parking lights on, hours later came back to fire up the engine from cold start and my HV battery bars went from 6 to 2 within minutes of driving because HV battery started charging the 12v battery. That was the only time bars drop like that and hasn't happened since. So if your yellow top ain't holding a steady to near full charge anymore, the HV battery could constantly be sending charge to the 12v battery and inverter using more electricity calling ICE to regen more leading to the MPG drop. Hope you resolve the issue soon, when my MPGs drop I go into freak out mode.
     
  2. FriedCells

    FriedCells Member

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    Thanks for the ideas. I just ran the 2 tests now. See pics below. Would the battery at that life expectancy cause a sudden drop in mpg's?
    FullDiagnostic_2020-10-12_04-59-06.jpg LifeTest_2020-10-12_03-41-35.jpg
    I did change the inverter coolant 6,000 miles ago according to NutzAboutBoltz videos on it, and bled it properly, etc. I haven't checked for swirling in the coolant, but I'll add it to the list of things to check.
     
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  3. FriedCells

    FriedCells Member

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    Thanks for the ideas. I'll try working on that and other ideas tomorrow. I'm wondering now if it's the hybrid battery as I just used the Dr Prius app to test it and it shows 47% battery life left and weak module at block 9....
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    That's a good one lol.
     
  5. FriedCells

    FriedCells Member

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    Truly appreciated. I'll add it to the things that I'll check tomorrow. I understand the freak out. It's been quite unpleasant looking at my mpg's at these levels and driving me nuts scouring the entire interwebs looking for a clear idea on what happened. I've posted on various forums in my life but I've never started my own thread asking for help. I always search, research, search, research, try things out, and usually find a way through most things without bothering other people asking for help. But after several months of seeing these bad mpg's, checking and rechecking things, reading and researching everything that my brain can handle, I finally broke down and just looking for any and all ideas. Hopefully will resolve it soon....
     
  6. ASRDogman

    ASRDogman Senior Member

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    Maybe a Prolong set up could be worth checking into.
     
  7. royrose

    royrose Senior Member

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    That test is just an estimate but 47% is really low. The test basically measures how quickly the battery depletes under load. So it makes sense that that can cause the ICE to run more and use more gas. Because these tests are not perfectly accurate, you might repeat them in a day or two to see if you get similar results, including if the same block is identified. How about a screenshot of the main battery performance page?

    Question is, what to do to pursue this. I'm not a battery expert, so others might chime in. If there is a trusted hybrid repair shop nearby, I'd get a professional opinion.
     
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  8. FriedCells

    FriedCells Member

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    I like the idea of that. Unfortunately, I live in a cottage that does not have a driveway or garage. I park on the street. So running that equipment with an extension cord across the sidewalk might get me in trouble if somebody would trip on it or whatever.
     
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  9. ASRDogman

    ASRDogman Senior Member

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    Yes, that does present a problem. If you know someone who could loan out there garage
    or driveway to you, that would be nice.

     
  10. FriedCells

    FriedCells Member

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    Yes, I'll check it again in a day or 2. I did the 2 tests that were available. The other page looked like a live monitoring page. Is that what you mean? I think they were the only 3 options. But since that live monitoring page was constantly fluctuating, I didn't think a screenshot would be that useful. I'll look at it again when I test it again.
     
  11. royrose

    royrose Senior Member

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    Yes, that's the page. The resistance levels at the bottom of the page are more consistent than the fluctuating voltage levels and can indicate a poorly functioning block.
     
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  12. FriedCells

    FriedCells Member

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    Do you have one of the Prolong systems? Just curious if it's even worth it. The cost is between $500-$700 for the recondition kits. A new battery from a guy in this forum (toast21k or something like that) is $1,600. Or from greentec auto with unlimited miles and 4 year warranty for $1,750. So the Prolong system would need to prolong the battery by at least 45% more life to be a reasonable expense. I just wonder if it is really capable of that or how that can be proven. It's quite an expense, so would love to hear more about it before jumping in on that.
     
  13. FriedCells

    FriedCells Member

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    Ok, thanks for the details. I'll definitely take a closer look at the next test.
     
  14. ASRDogman

    ASRDogman Senior Member

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    I do not have one, but wished I did. But I don't have a spare $650 to purchase one.
    Other things are more important right now. Seeing as my battery is 11 years old, and
    still seems to functioning like it did when I purchased the car 3 years ago, I know I "should"
    get it set up and run it through it's steps to keep it working... butttttttt....

    From what I've read about it, it has gotten very good reviews. And I'm certain it does what
    it is suppose to do.

    I'm hoping in the next 6 months I will be able to get one.
    Plus, $650 is a lot less than $1600, and a lot less work! :)

    It is an option for you.

     
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  15. Xterra72

    Xterra72 Senior Member

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    Just my experience, but I had the same thing happen with engine overheating. Long story short, my engine water pump was on its way out so I had that replaced along with the thermostat for good measure. All good now.
     
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  16. FriedCells

    FriedCells Member

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    So, I did 2 more battery tests today. One showed 48% life left, and the other showed 36% left! Quite a wild difference. Also, got a screenshot of the live battery monitoring screen. See photos.
    Capture+_2020-10-13-12-26-41.png Capture+_2020-10-13-14-12-38.png Capture+_2020-10-13-14-22-08.png
    Also, made a 7 minute video monitoring the live battery data. Not sure what it all means. Here's a link to that:

    Either way, it seems that my battery is on it's way out. I didn't really consider it as I saw so many people whose batteries lasted into the 200k range. But one thing that happened soon after all my work @150k miles is that I went through 1 of those car washes that you put your car in neutral and it pulls you along. I've done that many times before, but this particular time, there was a long line and it was hot. Had AC on and battery was fairly drained by the time that I got to the wash. Soon after putting it in neutral, the car started screaming at me about low traction battery, warning lights, telling me to put it in drive, etc. I did not know that the engine can't come on in neutral. Never encountered that situation before. I could not put it in drive in the situation, and the battery went all the way down to 0 bars before I got out of there and could get the engine on again. I thought maybe that happening one time wouldn't be such a big deal. But perhaps that did some irreversible damage and has been the cause of my low mpg's all along??? Should be a major warning to not use those carwashes if that's the case!
     
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  17. ASRDogman

    ASRDogman Senior Member

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    That looks pretty cool.. Don't understand the color changing. But I'm sure it means something.
    It looks like it's out of balance. Can't see what the voltages are.
     
  18. FriedCells

    FriedCells Member

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    Hey, in my post above, you can see some new details that lead me to believe that the traction battery is the issue. Just wanted to let you know what I'm planning to do in case it's something you might want to do someday to save money. I saw this video and some other videos of guys that were able to recondition their batteries using another method:

    I spent $200 to get 2x 4 port RC battery charge/discharge units similar to the ones in the video. I was fortunate to find some locally in classifieds at a good price. But there's also a 4 port charger on Amazon for $139. So, I'll be able to charge/discharge 8 battery modules at a time following the way that he did it in the video. It basically seems like it does the same as the Prolong system. It is more laborious and time consuming. But I like the idea of checking each battery module, replacing the 2-4 that are probably not good, balancing and reconditioning the pack in this manner. And I'll plan to repeat the process every 50k miles. Will see how much more life I can get out of the battery. I will be working on this next week and let everyone know how it went. I'll probably be without my car for 2-3 days during the process. But I have a truck that I can use. So all good.
     
  19. royrose

    royrose Senior Member

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    I just ran the Hybrid Assistant battery life test on my 2010 with 100,000 miles. I do that about every 6 months and was due. I got about 63%, about what I did 6 months ago.

    i believe that your car wash experience confirms the problem that Hybrid Assistant identifies, that your battery drains quickly under load. I don't think using that kind of car wash caused the problem. I use that kind of car wash and have never had that happen to me. Some batteries fail at this point, some last much longer.

    i think your battery, weak but not dead, is a good candidate for reconditioning. With reconditioning you may not have to replace any modules right away. I'll look forward to learning about your experience.
     
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  20. FriedCells

    FriedCells Member

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    Yes, seems like now is the time to attempt reconditioning before getting any battery codes in the car. I bought a few modules anyways just to have since I'll have the battery apart anyways and if I identify any bad modules, can't wait a week to receive them. Found a guy on EBay with good reviews and has them at $22 each, with a 1 year warranty, guaranteed to hold up to and over 7.6V each. So, good to have a few on hand.
    I agree that the car wash didn't cause the problem with the battery, but I do think the unique circumstance likely caused a quickening of the degradation. I've also been through those washes many times. But I guess I usually got to it with a medium-full battery, so it didn't matter. I hadn't seen a waiting line before quite like the line that day (15-20 min waiting, moving slowly), so I usually didn't have to wait so long. And it was during one of the hottest periods of the year, so I needed my AC pretty high. With any Prius, in that situation, the battery would have been pretty low at the point of getting into the wash. And that, I think, is a situation that should be avoided. Because now your battery will continue to drain from the 2 or 3 bar bottom normal threshold and unable to turn on the ICE in neutral to recharge. If I would have known about all that ahead of time, I would have turned off all electrical draining items. So now, in that situation, if you enter a wash with only 2-3 bars and have AC and radio on or whatever, there's nowhere to go but less than 2-3 bars. That wash is a pretty slow one, doing many things. Maybe 3-5 minutes to get through. I watched my battery go down to 1 bar, then down to 0 bars by the end with nothing that I could do to cut on the ICE until I could put in in Drive again. I think draining the battery like that down to no charge certainly is hard on the system. But hard to know at what extent the battery was already degraded or further degraded from that situation. But for me, I'll definitely be making sure that I don't enter a wash like that again at the 2-3 bar bottom battery threshold again. If I have to, I'll force charge the battery by having foot on brake and gas like the Dr Prius app does to recharge the battery some before entering the wash.
     
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