PRIME is the third worst in the battery degradation. How is yours holding up?

Discussion in 'Prime Fuel Economy & EV Range' started by Salamander_King, Jun 28, 2020.

  1. DD1

    DD1 Junior Member

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    If the “safety margins” stay constant over time, wouldn’t the number of kWh to charge from 0 to 100 percent usable capacity be a good indicator of the health of the battery? The battery capacity is supposed to be 8.8 kWh. If the safety margins add up to 25 percent, then one would need 6.6 kWh for a “full” charge. If the safety margins add up to 30 percent, then you will need 6.16 kWh. Some people on other threads mentioned numbers up to 7, wouldn’t that imply a very narrow safety margin?

    Please point me to another thread if anyone already has an explanation of that - I am a new owner and still trying to figure things out.
     
  2. jerrymildred

    jerrymildred Senior Member

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    Here are a couple screen grabs from videos that show the actual charge at "depleted" and "full." At 14% actual as measured by Hybrid Assistant, the car considers the traction battery depleted.
    Screen Shot 2020-11-08 at 1.53.00 PM.png

    Full charge is 83% using the same app.
    Screen Shot 2020-11-08 at 1.53.00 PM.png
    Thanks, @john1701a for the great videos!!! Check out his web page at John's Stuff - Toyota Prius and more. It's an excellent resource.

    So, 14% at the bottom + 17% at the top is a reserve of 31%. That leave 69% available for driving. Actual capacity is 8.79 kWh. 69% of 8.79 is 6.06571 kWh available for driving. The kWh needed to put that much into the battery will be somewhat higher due to heat loss, fans, etc. and not all kWh meters are created equal. Plus, it's rare to catch the battery right at an actual 14% real world SOC when you start charging, so that's another variable in what you'll measure at the wall.

    What this boils down to is that aiming for precision in this investigation is a whole lot of work for not much return. I'll repeat the friendly suggestion I and others often make on this forum. Don't obsess. Just drive it and enjoy it. It's a wonderfully efficient and reliable car.
     

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  3. John321

    John321 Senior Member

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    I would agree with what Jerry says

    This study seems to give no information of the quantity of the actual cars tested. For example of the 6300 electric vehicles how many where Prius Primes 1,2 3 how many? Under what conditions where they driven and maintained?

    Our PHEV is listed as one of the very worst for battery degradation. We plug it in at all times and make no effort to molly coddle the battery. Now closing in on two years of ownership we see no battery degradation and will get close to 30 miles per charge, under ideal conditions in moderate weather can approach between 35 or 40 miles per charge. The vehicle is rated for 26 miles for a full charge.

    I would lose no sleep worrying about a PHEV battery degradation.

    Toyota and other manufactures team up with battery manufacturers and design batteries and battery management system that are state of the art so we don't have to waste time thinking about or monitoring them ourselves.
     
    #23 John321, Nov 8, 2020
    Last edited: Nov 8, 2020
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  4. vvillovv

    vvillovv Senior Member

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    One has to remember there are losses all the way alone the chain from where you plugin to the amount of that energy gets used where rubber meets the road.
    There is 120v and 240v charging capibility for the Prime. Both have a high 12 or 16 amps respectively as well as 8 amps for both.
    If you test with the Kilawatt meter at both settings and both amp ratings, it should at least give clues to why some see higher kwatts per charge while other see lower rates.
    Than there is the differences in the meters as well as the differences in the Primes.
    And all the other differences, I like to call variables.
    From a realistic point of view, between 6 and 7 Kwh per charge is not that great a difference, when considering all the other variations to take into account.
    I'd like to see some too.
     
  5. Henrik Helmers

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    Agreed. It is a pretty good position to be in when the worst thing that can happen is for the gasoline engine to spin up. I have started missing the engine hum at startup ever so slightly. :whistle:
     
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  6. JMalmsteen

    JMalmsteen I love my Prius!

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    We have 160k miles on our 2017, and no issues with battery degradation. I get around 30 miles on a charge.

    This car is fine. I was going to buy a Tesla Model S 90D with 25k miles, its 294 capacity was at 264 maximum range, and Tesla thought that was within spec. That's a problem, not Prime range.
     
    #26 JMalmsteen, Nov 11, 2020
    Last edited: Nov 11, 2020
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  7. vvillovv

    vvillovv Senior Member

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    an interactive graphic showing Avg. SoH for some of our favorite ph-EV's
    viewers can compare makes and models dating back as far as 2012 in some cases.
    see how the data collected so far for your year and model compare to the average of all vehicles for the data that's been collected for each to date.
    Geotab - EV Battery Degradation
     
  8. Salamander_King

    Salamander_King Senior Member

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    Yap, that is the source as I pointed out on my original comment. What can 6,000 electric vehicles tell us about EV battery health? | Geotab But the data used for their analysis is very limited to the fleet companies who agreed to have the information monitored by their propriety telematics data module. I and many others here suspect, to say the least, the result is very misleading if not outright meaningless.
     
    #28 Salamander_King, Nov 12, 2020
    Last edited: Nov 12, 2020
  9. vvillovv

    vvillovv Senior Member

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    No disrespect intended. That makes two posts of mine in this thread that look too familiar to previous posts by others.

    My thought after reading all the posts in this thread, although not clicking on the OP link, was to do my own search of the actual (tool) used by GeoTab to see if I could make more sense of how the thing actually works.

    Than, I got sidetracted for an hour and when I got back to the GeoTab search I thought the link to the simple graphic without all the technical info and explanations being debated in this thread might be useful to some.

    I did notice a few interesting plots on the graphic though. Also didn't notice much of a difference in Degradation across the model range. Besides many of the models listed have only been available for 2 years 2018 and 2019. A couple models only available for 1 year and only 2 models available since 2012.

    But the models that have data for more than 3 or 4 years seem to carry the burden of the default Average Degradation slope.

    .
     
  10. Salamander_King

    Salamander_King Senior Member

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    The biggest problem with what the tool shows is that although the original article states that "an analysis of 6,300 fleet and consumer electric vehicles" were carried out, it does not disclose any detail of how many cars in each make, model and year were analyzed nor does it disclose the method used to calculate the SoH for the traction battery from the proprietary telematic data obtained from the vehicle. I am not aware of any quantitative value that can be read from any of sensors to reports value to ECU which in turn can be translated to % degradation of the traction battery used for this tool. So, I have to wonder the validity of the result all together. Even if such data does exist and extract-able by an OBDII module, I would be very suspicious that such analysis would apply across all of BEV/PHEV with different control systems.

    There is no statistical error bar. It could well be a single vehicle used on not so average fleet driving condition represents the entire class of Prius Prime 2019 model which shows third worst 1 year degradation of 2.3% compared to the best performer as far as the battery degradation is concerned, the Chevy Bolt 2019 model of 0%. It offers no explanation as to why the 2019 PP does so much worth (2.3% degradation at 8 mo) than 2018 PP (0.1% degradation at 8 mo).

    Geotab - EV Battery Degradation
    upload_2020-11-12_13-17-21.png
     
    #30 Salamander_King, Nov 12, 2020
    Last edited: Nov 12, 2020
  11. Mikhail Bond

    Mikhail Bond Member

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    I’m at 145k and still charge up to 24 miles
     
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  12. jerrymildred

    jerrymildred Senior Member

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    How many miles per kWh are you getting. 24 miles could be great or terrible depending on how many miles you get out of a kWh.

    ie: if you're getting 4 miles/kWh, that means the battery is letting you use 6 kWh and taking you 24 miles. On the other hand, if you're getting 5 miles/kWh, the car only has 4.8 kWh available which is taking you 24 miles.
     
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  13. Paul.Ivancie

    Paul.Ivancie Member

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    I thought that I would add my two cents worth to the conversation. I have not gathered precisely-measured data, like I did for my 2006 Prius, so my observations are empirical “thumb-in-the-wind” measurements.

    I have owned my 2017 Prime for almost four years now (Mid-May anniv.) and have not noticed any significant traction battery degradation, except for the cyclic summer/winter hit. For the first two years of ownership, I was long-distance (1K miles) commuting on a regular basis, accumulating about 40K miles split evenly between local driving and those trips. I charge up away from home whenever I can find an available supply point. Now, driving almost exclusively local errands has reduced my yearly miles driven by about 25%, and increased my EV driving percentage to the high nineties. My EV MPKwH sits at 4.8 for the last 30K miles, since I reset my History due to a display panel replacement at about 40K miles. I cannot say for sure, but I believe I was over 5.0 at that time.

    During the winter, EV mileage gets hit pretty hard. (My grandchildren live on top of a (snowy) hill.) Since we live in a semi-rural area, slush on the road also adds significantly to the drag coefficient. I have experienced full-charge excursion ranges under 19 miles. On the other hand, as soon as the weather breaks, like this past week, EV range bounces right back into the 30’s. When all conditions were just right, I have squeaked out close to 40 miles on a single charge. (NOT all downhill, for you cynics out there!)

    I have settled into a routine: I buy gasoline (always non-ethanol) on either the last day or the first day of the month, if possible. My usual outlay for this fill-up (or more accurately, top-off) is about 75 cents. I have had to rescale the MPG axis of my trusty rusty economy spreadsheet graphs to logarithmic, starting in the third year of ownership. That is the only way to handle some MPG data points, which are typically in the thousands. I realize that this spreadsheet is lacking some perspective, in that the MPG vertical axis should reflect the effective MPG, by including the cost of electricity used to charge up the electrical energy-storage “tank” and using it and the current price at the pump to estimate the equivalent volume of gasoline that it displaces. I’m working on the upgrade now. Since I bought a home-based ChargePoint™ charger last year, I can easily supply exact data for my electrical usage since then, and I will backfill (this is where my “thumb in the wind” comes into play) for my initial years’ usage. I will upgrade my spreadsheet and check back in with actual data.
     
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  14. Raytheeagle

    Raytheeagle Senior Member

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    Here's our 2019 that we have had almost exactly 2 years to the day and put 36k miles on it:):

    C9B01D20-BB20-426A-923E-E7C4CA8A6A15.jpeg 7AD6C7AD-0B52-419F-B1D9-DD14E98C3647.jpeg

    Not too shabby(y).
     
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