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Lower Half of Battery Discharges More Quickly

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by SDSUsnowboards, Sep 25, 2019.

  1. SDSUsnowboards

    SDSUsnowboards Junior Member

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    2013 Prius 3. 136k miles.

    The Prius is new-to-me. Lately I’ve noticed a peculiar thing about the rate of discharge for the battery. It seems to me that the battery discharges more quickly once it falls to the half-way point (4 bars) even though my driving habits are not changing. Then, eventually, the ICE regenerates the battery back up to 3 bars, and that charge lasts a good long time!

    My driving habits are such that I do not rely much on EV-only driving. If and when I do use EV-only driving, I try to fill up less than ¾ of the EV bar on the dash.

    Anyway, I’m averaging about 50 *actual* mpg per tank, which seems good to me, and it suggests everything is working as it should.

    What do you think? Is the non-linear, conditional, rate of discharge normal?
     
    #1 SDSUsnowboards, Sep 25, 2019
  2. wheezyglider

    wheezyglider Active Member

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    To be honest I haven't noticed the non-linearity you observed, but if you're getting 50mpg you're fine - let it do its thing. You can estimate the capacity of the battery using the Dr. Prius app (or procedures you can search for in this forum), but mpg is where the rubber meets the road.

    If you want something to worry productively about IMHO, read up on the EGR cooler threads. :)
     
    #2 wheezyglider, Sep 26, 2019
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  3. bisco

    bisco cookie crumbler

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    ^agree^
     
    #3 bisco, Sep 26, 2019
  4. davecook89t

    davecook89t Senior Member

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    #4 davecook89t, Sep 26, 2019
    2012 Prius v wagon 3, m.wynn, Raytheeagle and 4 others like this.
  5. SDSUsnowboards

    SDSUsnowboards Junior Member

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    Awesome, graphic! if I am interpreting it correctly, then it would explain what I'm seeing. It's weird that there is a lag. I wonder if Toyota did that to prevent constant fluctuations between bars.

    What is the issue with the EGR cooler? Needs periodic cleaning?
     
    #5 SDSUsnowboards, Sep 27, 2019
  6. jerrymildred

    jerrymildred Senior Member

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    The overlap is just a natural function of sensing devices whether electronic or manual such as pressure switches.

    As for your gas mileage, it's really good considering that you seem to be deliberately punching the EV button. Try letting the car decide when to run the engine. I'm guessing you'll get even better gas mileage and have a more relaxing drive. The EV button is mainly so you can move the car into or out of the garage/driveway and stuff like that. Just for drives that are too short to be worth starting the engine.

    As to the EGR cleaning, it's a widely held belief that as the Gen 3 approaches 100,000 miles, the EGR system gets clogged to the point where there's a risk of blowing the head gasket. AFAIK, there's no solid proof of that, but there does seem to be a lot of anecdotal evidence.
     
    #6 jerrymildred, Sep 27, 2019
    Last edited: Sep 27, 2019
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  7. wheezyglider

    wheezyglider Active Member

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    What Jerry said. At your mileage its worth planning for soon. And if you start hearing a rattle on startup get on it quick. Do the spark plugs and PCV valve while your at it. Also check your oil level often (I do it every fill up), after 100K they can go from burning no oil between changes to burning a quart or two without warning.
     
    #7 wheezyglider, Sep 27, 2019
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  8. SDSUsnowboards

    SDSUsnowboards Junior Member

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    Thank you for the advice, guys. I'll get on those things. I figured it was time for spark plugs and PCV, but never would have considered the EGR. Hopefully the 3rd gen prius will prove as reliable as the 2nd gen. We're hoping to have this car trouble free for at least 6 years.
     
    #8 SDSUsnowboards, Sep 28, 2019
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  9. jerrymildred

    jerrymildred Senior Member

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    Based on what I read here, it sounds like the Gen 3 is very reliable. As with any car, you need to maintain it and the gen 3 does have this extra item to see to, but otherwise, it's great.
     
    #9 jerrymildred, Sep 28, 2019
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