Charging to 80% ? 100% from ?

Discussion in 'Hyundai Kona Electric' started by Tim94549, Dec 22, 2019.

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  1. marshall

    marshall Well-Known Member

    Does Hyundai have a capacity loss warranty, or does the traction battery have to have a dead cell before they will replace it? Unfortunately, the warranty is only good for the original owner in my Sonata plug-in.

    Anyhow, if the traction battery can retain at least 50% of it's original 200 mile plus, capacity, it should be a viable used car for many folks.
     
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  3. ericy

    ericy Well-Known Member

    Just wish it had the battery warmer.

    I have been sort of wondering about the possibility of installing one - there is a software component in that our cars have no "Winter Mode" on the display that can be turned on/off. Thus it is likely that dealer assistance would be required, but Hyundai would need to come up with the instructions first.
     
    KiwiME likes this.
  4. This may or may not be helpful to you but in Canada the language for the warranty on the 2020 traction battery is very specific to repair or replacement if capacity drops below 70% and it goes on to say that Hyundai's warranty obligation is to repair or replace to to achieve only a 70% capacity, and specifically states a repair or replacement does not ensure a new 100% capacity battery. Meaning they could put in in a used or refurbished sub module that brings it over the 70% threshold and call it a day. The battery is broken up into 5 sub modules as available parts. The individual cells are not available so I suspect they can change out affected modules or the entire pack if necessary or cheaper from a labor perspective.
     
    Last edited: Dec 24, 2019
  5. I not sure how uber important the battery heater is for most of the Continental US. I have been driving this week in -12C with winter mode on I don't think I have had the battery heater come on yet according the battery care monitor. I tried fast charging on a new 250 kw charger at 50% SOC and the best it gave me was 23kw charge at -13C. I understand it does come on at -17 C and colder. Now the heat pump is the bomb, I really like that and I would pay more for it if I had to. So far this is a great little winter car, pretty much instant heat, great traction, less range but whatever I get less range with my ICE car too. I am tepidly curious what -35C is going to be like.
     
    SkookumPete likes this.
  6. What would be critical is having the sensor (black) wiring in place, marked with the arrow. It appears the HV cable is tethered and plugs into the battery housing, so there also needs to be a corresponding receptacle present. Here is the unit from the underside, also visible from the firewall.
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  8. Ok, I guess the battery heater does do something outside of extreme cold. I see in the manual it implies the heater comes on while plugged in, to some unspecific parameters. My Kona was parked plugged into the level 2 EVSE outside last night with ambient temps -8C overnight, according to torque pro it looks like it heated the battery up to a high temp of +11C and the average pack temp was +7C this morning. That is around a 15 degree spread over ambient. I suppose some of the heat is from the charging process but I only required a 10% charge so I suspect it was mostly heater. I can now appreciate how the battery heater would make DC charging faster and generally be helpful.
     
    GeorgeS likes this.
  9. The resistive heat loss from a 7.4 kW charge rate would only be around 150 watts max according to my estimate, nothing like the ~2kW that I understand the battery heater can provide. And even that sum total would be fighting the environmental heat loss from the large and presumably uninsulated battery housing.
    There must be a BCM algorithm that decides if diverting charging power to the heater is worthwhile to improve charging speed. Certainly I've seen the heater come on under DC charging when the pack temp is under 15°C, accompanied by the sound of the coolant pump and a few gurgles while it purges air. Once at 15 the charge rate abruptly increases and the heater and pump switch off.
    The effects, if any of the heater while driving has not been documented by anyone as far as I know.
     
  10. There definitely is a BCM algorithm that correlates charge speed to battery temperature.

    Hit a 350KW DC charger today. Starting SOC was 15% and ended at 55% with ambient temperature of -9C. The charger hit max charge rate of 78 KW/hr around the 20 minute mark at around 50% SOC. With the help of torque pro it was interesting watching the battery heater temp, battery inlet temp and battery temps correlate to the charge profile. Battery heater hit a max temp of a toasty 113C, inlet temps went as high as 31C( and back down to 8 C at 55% SOC) and in a matter of around 20-25 minute the battery bank temps went from 4C to 28C. Its clear that without a battery heater DC charging would be painfully slow in winter conditions.

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  11. NRH

    NRH Active Member

    We don't have a battery warmer (Downeast Maine, 2019 SEL), and I was a little concerned about DCFC speeds in cold weather.

    We haven't had to DC charge at extremely low temps yet, but on Tuesday at a 62kw charger, ambient temp 26F (about -4C), we got 40kW right out of the gate, and after 9 minutes it went up to 55kw (which from past experience seems to be the max for this charger), where it stayed until we unplugged 15 minutes later. We went from 10% to 55% SOC in about 25 minutes.

    So far, my feeling is that since DCFC is only used when the car has been driving at high speed for a couple hours already, the battery is warm enough that DC charging speeds aren't bad without the battery warmer. (Granted, I'd love to have one as it could speed things up just a bit, but I'm glad we didn't sacrifice an extra $5000 for the 2020 Limited, and give up the 2019 Lifetime Battery Warranty just to get the battery warmer.)
     
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  13. ericy

    ericy Well-Known Member

    I was on a DCFC early this morning, and I was mostly pulling 24kW. Maybe 10 minutes it was 42, but the rest of the time it was 24.

    This is a free 50kW charger - if I were paying by the minute I would be really annoyed. Even as it was, it took longer than I would have liked.

    Temperature was something like 28 degrees. I spent just over an hour to charge from 41% to 80%.
     
    Last edited: Jan 9, 2020
  14. My measurements indicate that the battery heater warms the battery about 5°C every 10 min in a 12°C ambient, while DCFC. The full charge rate is possible once 15°C is reached so you could still have had to wait 30 min if your battery was as cold as your ambient. Above 72% 24kW is the best rate on that 50kW charger anyway.
    Another thought is that charging (or driving) resistive losses are perhaps at least 2%, so at 24 kW that's 485 watts. I think the battery heater is around 2kW.
     
  15. ericy

    ericy Well-Known Member

    Yeah, but US Kona have no battery heater. Not for 2019, anyways. So we are stuck with a slow DCFC charge.

    When I am in the city, I have no easy access to a level 2 charger, so I have to rely on DCFC to charge up for the trip home.

    This morning i started at 75%, and got home with 13%. In warmer weather i can do a lot better, of course. Trip is 150 miles.
     
    Last edited: Jan 10, 2020
  16. GeorgeS

    GeorgeS Active Member

    We are going to take a major (1,000) trip in the middle of winter. Since many DCFS charge by the min., and the distance between chargers is great, I fear we will be paying a great deal for our charging. The cost of a charger seams like it would return the investment if you had to make many winter trips. What are your thoughts?
     
  17. I was on a trip yesterday, and did a couple of stops at a fast charger. I noticed that at 70% it throttled down to 35kW, same both times. So I just charged a little beyond that and moved on. I have never fast charged above 80%, so not sure how much further it throttles back, but would expect even more. I think there are probably charts here somewhere that describe that.
     
  18. NRH

    NRH Active Member

    Not sure what you mean about the cost of a charger returning the investment. A DC fast charger isn't really an option since you can't take it with you on long winter trips, and it costs tens of thousands of dollars.

    If you're taking a 1000 mile trip, and you have Level 3 chargers at 150 mile intervals along your route, and if your expected temps are 20F and above, I don't think you'll have any problems. Around here, we have L3 charging stations anywhere we'd normally stop to use the restroom and get coffee or snacks. A 20-30 minute charge every 2 hours works about right to get you there. Our rest breaks are about the same as with a gas car, just slightly more leisurely sometimes.
     
  19. I'm going to guess maybe Georges was referring to additional cost for battery heater. If yes I absolutely agree the battery heater makes a significant improvement on dc charging speed in temperatures below 0C.

    Sent from my SM-G955W using Inside EVs mobile app
     
    GeorgeS likes this.
  20. GeorgeS

    GeorgeS Active Member

    Sorry, I did mean cost of the heater.
     
  21. NRH

    NRH Active Member

    Ah yes, we debated that as well. In the end, we couldn’t justify the extra $5,000 for the upgrade trim package, just to get the heater, plus losing the lifetime battery warranty that came with the 2019. We’ll see if we regret that decision Pond some mid-winter trip sometime in the future! We rarely need to use DCFC, and the car has charged at 55kw mid trip at 27F ambient temp, so hopefully it’s not a problem we have to contend with.
     
  22. I guess it really depends how miserable your winters are, how long and indeed mostly how often you need to hit a DC fast charger. If you do mostly home charging you won't appreciate any real difference. I have been watching closely and in generally driving conditions the heater does not come until the battery pack gets to ~-17C and that is likely just preserve some regenerative capacity and more likely to protect the battery pack from the risk of freeze damage. Otherwise the only time it consistently comes on is with DC charging and any reasonable colder pack temp. It seems its target goal is to warm up the pack temperature to above 25C which depending on SOC allows you to max charge of 78 kw/hr.
     

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