Premature range loss

Discussion in 'Hyundai Kona Electric' started by 170/daykonaguy, May 19, 2019.

  1. XtsKonaTrooper

    XtsKonaTrooper Active Member

    Screenshot_20190526-212347.png
     
  2. XtsKonaTrooper

    XtsKonaTrooper Active Member

    There are some of the major screenshots of the app.
    Def nice info to see, especially in the winter time.
     
    electriceddy likes this.
  3. electriceddy

    electriceddy Well-Known Member

    Does it give independent cell group voltages ( IIRC 98 S cell groups of 3P) at least to give an indication of weak cells?
    Also make of your ODD2 dongle ( does it use bluetooth 1.5) also phone model and android Version as I am in the market for a (new?) one, Thanks
     
  4. XtsKonaTrooper

    XtsKonaTrooper Active Member

    No it doesnt give independent cell V
    Here is the Bluetooth scanner
    Panlong OBD2 OBDII Bluetooth Scanner ELM327 Check Engine Light (MIL) Car Diagnostic Code Reader for Android https://www.amazon.ca/dp/B07C3D2NZ7/ref=cm_sw_r_cp_apa_i_XAi7Cb7QZ7F0G.
    Im using it on Android 9 and the phone is a Razer 2.
     
    electriceddy likes this.
  5. brulaz

    brulaz Active Member

    What does "Battery Health (SOH)" mean?
     
  6. XtsKonaTrooper

    XtsKonaTrooper Active Member

    ^^^^^
    State of Health
     
  7. brulaz

    brulaz Active Member

    So what does "State of Health" mean?
     
  8. brulaz

    brulaz Active Member

    Wikipedia gives a general idea about what battery SOH means: https://en.wikipedia.org/wiki/State_of_health
    Presumably the EVNotify app gets the SOH from the vehicle battery's BMS?
    But there doesn't seem to be any industry consensus as to how the BMS measures/calculates it.
     
    Jared Potter likes this.
  9. Jared Potter

    Jared Potter Member

    State of health is a highly subjective term that is entirely managed by the on-board battery management system. The state of health is most likely individually like a non-standardized list of sub categories similar to a SMART report generated by hard disk drives in computers. The battery system is clusters of batteries in series (that allows the 1.5v individual cells pair together to achieve the high voltage output of 200+ volts as well as the cell series groups are stacked behind each other to create mass storage (parallel). The batteries need to be carefully managed both during recharge and discharge to make sure individual cells and groups are drained and refilled together and to monitor if battery packs are failing to hold charges and such. If this isn’t monitored and managed by the system an imbalance will occur and you’ll be told the battery is at 100% when in fact it might be 75% and you’ll see a drastic drop in range etc. The system needs to be able to track and report if a particular pack is failing so during maintenance a pack can be swapped that is prematurely failing or otherwise not working as expected. Also obviously it also tracks and monitors overall health and wear so the storage from a “new” state is determined. This entire system would be entirely proprietary and designed and managed by the battery maker and car manufacturer. Basic data can be read and determined by the obd2 system most likely hence all that data being converted into a state of health but their own systems can probably generate the detailed report from the battery system to figure out what, if anything, is wrong.
     
    Kitsilano likes this.
  10. brulaz

    brulaz Active Member

    Thanks. Perhaps the battery's SOH as reported by the BMS is checked during routine maintenance.
    But I see zero mention of it in the manual. All the maintenance checks appear to be mechanical (except for the 12V battery check).
    Presumably one of the warning lights (Service, Power Down, Blinking Ready) will light up if something goes wrong with the battery, and SOH becomes bad, because of an unbalanced cell or whatever.
     
  11. electriceddy

    electriceddy Well-Known Member

    My guess is it is a calculation based on measuring the internal resistance of the pack ( which in turn affects the conductance expressed in mho's as when new (max voltage/amp hours) to the present state- (see chart V over I) :
    https://www.google.com/search?q=ohm...&biw=1415&bih=651#imgrc=osOUaq6w3IBFmM:&vet=1
    As the pack deteriorates the ion movement between the positive and negative electrodes decreases. SOH is then expressed as a percentage.
     
    apu and Kitsilano like this.
  12. apu

    apu Active Member

    From what I have read, unless there is an internal pack failure SOH seems to be reported simply as a "green light" on their diagnostic report to the service customer if the SOH is anything more than 70% and only if the service customer inquires about possible range deficits. Basically Hyundai doesn't want to you worry about SOH unless it meets their criteria for replacement which is less than 70%. That said I think there is value in SOH not so much as a diagnostic but as a trending predictive tool to help you appreciate what variables over time minimize degradation as much as possible.
     
  13. brulaz

    brulaz Active Member

    Apu, that seems reasonable, but it is unclear to me whether this is the # they would use for warranty evaluation.
    Maybe so.
    Does a 70% SOH imply that the fully charged vehicle's range is reduced to 70%?

    Nonetheless, and whatever SOH actually entails, it would be useful to monitor this # as you suggest.
     
  14. apu

    apu Active Member

    Sorry, I think I may have confused things a bit with my previous post. From what i understand SOH may possibly represent some degree of battery internal resistance, voltage, and temperature measurement but its just a representation of these various arbitrary data points that the manufacturer feels are most representative of the batteries overall health at that point in time and space. Its not a direct measurement of capacity but can be loosely correlated to it.

    In a warranty situation I suspect more than SOH reading is used to determine if the battery's capacity to store energy is below 70% which is their definition of end of life. I might imagine a test that involves a series of short static charge/discharge cycles to measure residual battery capacity. That said it appears that at least with older Leaf owners if their dash bar display which is effectively SOH meter indicates 8 out 12 bars they meet criteria of end of life battery replacement assuming they are still within their warranty period. I am sure the dealer still does capacity test to verify what the SOH meter is implying.
     
  15. Stevewallace

    Stevewallace New Member

    I had a 2002 Toyota Prius - what people do not realize about hybrids, that they continuously charge the battery to 100% even while driving. Mine lasted for 500,000 miles or 15 years. The car is still on the road with the same battery. Range fluctuates on so many variables. Just be aware where your charging options are.
     
    SkookumPete likes this.
  16. apu

    apu Active Member

    Your Prius has a metal hydride battery with different charging characteristics, not really comparable to lithium batteries used in modern EVs or even Prius models after 2015.
    Frequent high charging individua llithium cells at 4.2v(100% capacity) or higher will factually decrease their lifespan. Now again what the car says is 100% is not necessarily a true 100%, as the car displays your virtual battery capacity not its real capacity. You would need a scan tool and app like torque pro or EVnotify to see what is really going on.
     
    electriceddy, BC-Doc and Kitsilano like this.
  17. ehatch

    ehatch Active Member

    I would read about battery capacity at Battery University[ note figure 6] because it's really helpful. GM's Bolt EV owner's manual actually wants customers to charge to 100% as often as they want. ideally charge to 65-75% ; 25-85% will help with avoiding degradation.

    [​IMG]
     
    Last edited: Jun 6, 2019
  18. Colin Munro

    Colin Munro New Member

    I’m a bit like KiwiMe I don’t take all that much notice. I’m more concerned about how I should charge my kona. Some say never less than 20% or more than 80% unless going on a long run. Not sure who’s right so since getting the car in February I’ve stuck to the 20-80 formula


    Sent from my iPhone using Inside EVs
     
  19. electriceddy

    electriceddy Well-Known Member

    70% to 45% for me seems to work most of the time, on occasion to 80% if I need the range, mostly weekly L2 and DCFC 2 times a month
     
  20. Colin Munro

    Colin Munro New Member

    Thanks but your reply highlights what I’m saying, what is the best way to maintain the battery. Everyone seems to have a different idea including the Hyundai dealer.
     

Share This Page