Mike's wife's monthly Kona EV efficiency report

[navguy12]

I'm starting a thread to follow the "grid to wheels" efficiency of my wife's new 2021 Kona EV (Preferred).

I run a thread for my 2018 TM3 and it will prove interesting, to me anyway, to compare the real world energy efficiency between the two vehicles.

Obviously, I will only post Kona relevant information here, but for background on the TM3 efficiency one can check out this thread: https://teslaownersonline.com/threads/mikes-monthly-model-3-efficiency-report.8945/post-289980

My first month of data for the Kona is somewhat abridged as we took delivery on 20 Aug 2020 and since the dealership didn't fill up the battery, we had to do that at home.

If there is a more efficient way to draw information from the Kona than I have chosen (without the use of third party hardware/software), please speak up.

Aug 2020 results:



Note: the above data includes a top-up to 90% (34 kWh) the evening we took delivery of the car.

"Real Upload" page also shows lifetime difference (blue cells at top):


The above information was cobbled from the car's trip odometer. The "real" data is showing 80 kWh minus the 34 kWh we required to top up the battery (to 90% SOC) the evening we took delivery of the vehicle.

Raw data for Aug 2020:



Note: the raw "Eyedro" monitoring system is displayed only for reference at this time. The 01-20 Aug 2020 data that shows up on this shot is because the sensor for the system was being used to monitor our kitchen stove...thus the total energy used shows "89.289 kWh" versus the raw "dumb" monitor that shows "80 kWh" that flowed from the circuit breaker panel towards the Kona.

Summary costs as of 31 Aug 2020:



Total operating costs, per km (total costs minus capex costs):

$161.1455 - $155.408 = $5.7375/km

Obviously, the above (outlandish) cost per km becomes smoothed out with more distance traveled.

The above assumes "zero" value for the vehicle until it is actually sold at some future date.

For comparison purposes, the costs for my wife's previous car, a 2012 Toyota Yaris:



Total operating costs, per km (total costs minus capex costs):

$0.3850 - $0.164 = $0.221/km.

So, lets see how many months/km must be driven before the Kona operating costs are less than 22.1 cents per km.

 

[navguy12]

Sep 2020 results:


"Real Upload" page also shows lifetime difference (blue cells at top):


Raw data for Sep 2020:



Summary costs as of 30 Sep 2020:



Total operating costs, per km (total costs minus capex costs):

$45.7254 - $43.4017 = $2.3237/km

Discussion: The insurance for the next 12 months was paid this month.

Like my TM3, the insurance will ultimately become the largest operating expense on a per km basis.

The "Purchase" total is larger this month as it includes the Opti-Coat (ceramic) procedure as well as the winter tire/wheel package.

The "Reg Maint" charge of $98.13 was for the 12 cans of Krown rust spray.

 

[electriceddy]

Sep 2020 results:

View attachment 9441
"Real Upload" page also shows lifetime difference (blue cells at top):

View attachment 9442
Raw data for Sep 2020:

View attachment 9445 View attachment 9444 View attachment 9443

Summary costs as of 30 Sep 2020:

View attachment 9446

Total operating costs, per km (total costs minus capex costs):

$45.7254 - $43.4017 = $2.3237/km

Discussion: The insurance for the next 12 months was paid this month.

Like my TM3, the insurance will ultimately become the largest operating expense on a per km basis.

The "Purchase" total is larger this month as it includes the Opti-Coat (ceramic) procedure as well as the winter tire/wheel package.

The "Reg Maint" charge of $98.13 was for the 12 cans of Krown rust spray.

Still some time to go to reach your goal, thanks for and appreciate the updates...a lot of work involved in this.

 

[navguy12]

Cheers.

I'm a data nerd.

When I talk EV's (and the like) with newbies I never say anything I cannot back up with data.

 

[navguy12]

Oct 2020 results:




Raw data for Oct 2020:



Summary costs as of 31 Oct 2020:



Total operating costs, per km (total costs minus capex costs):

$25.1608 - $23.8706 = $1.2902/km

 

[navguy12]

Nov 2020 results:



Raw data for Nov 2020:



Summary costs as of 30 Nov 2020:



Total operating costs, per km (total costs minus capex costs):

$24.2671 - $23.0218 = $1.2453/km

The Kona sits in the garage as my wife recovers from elective surgery. Normal driving patterns should re-commence mid December.

 

[navguy12]

Dec 2020 results:




Raw data for Dec 2020:




Summary costs as of 31 Dec 2020:


Total operating costs, per km (total costs minus capex costs):

$20.7437 - $19.6747 = $1.0690/km

 

[navguy12]

Jan 2021 results:




Raw data for Jan 2021:





Summary of costs as of 31 Jan 2021:



Total operating costs, per km (total costs minus capex costs):

$16.1146 - $15.2780 = $0.8366/km

 

[electriceddy]

Jan 2021 results:

View attachment 10586

View attachment 10587
Raw data for Jan 2021:

View attachment 10585

View attachment 10584

Summary of costs as of 31 Jan 2021:

View attachment 10588

Total operating costs, per km (total costs minus capex costs):

$16.1146 - $15.2780 = $0.8366/km

Interesting info, the distance on the odometer is close to my monthly average. Congratulations on breaking the loonie per km operating costs

 

[KiwiME]

The car's "accumulated info" compared with actual AC kWh drawn being at 97% (139/144) does not seem realistic. The best possible OBC efficiency alone is 91% and there are many additional overheads such as running the car's electronics and charging the aux battery.

For troubleshooting the most accurate intermediate data available is the energy supplied to the battery and that's obtained by reading CEC (from an OBD app) before and after charging. The difference is the actual kWh delivered to the pack. The readings will still be valid even taken some hours before and after the charge duration because the only periodic live load to the pack is aux battery charging and that depletion is minor in comparison to what you're adding.

I believe the accuracy of the BMS's current and voltage measurements are likely very good because the accuracy of the running SoC is entirely dependent on that, and it's DC. Those values would be integrated in real time by the BMS to add to accumulated kWh.

I charge at only 1.7 kW so losses will be somewhat higher but typically my battery pack receives 84% of the AC energy delivered. I've verified the AC energy measurement device by comparison with a true RMS DMM on a similar fixed resistive load and they concurred to 99%.

The car's "accumulated info" should use the same BMS hardware but for current leaving the battery. That would be affected by pack cycle losses which are 2% in my estimation.

 

[navguy12]

The car's "accumulated info" compared with actual AC kWh drawn being at 97% (139/144) does not seem realistic.

I think you forgot to add the energy added to the car in locations other than "home" for this month.

A quick review of the Jan 2021 results:



On 04 Jan 2021, we went for our first test of a high speed, level three charger.

According to the screen shot of what was dispensed on 04 Jan 2021:



...plus what was drawn from the grid for all other times this past month:



...gives the total of (18.712 + 144) 162.712 kWh.

Again, a review of the Jan 2021 data:



In the above screen shot of my spread sheet, for the month of January, the car odometer based uplift of 139 kWh is derived from 175 Wh/km multiplied by 795.5 km traveled (equals 139.2125 kWh, spreadsheet figures as shown are rounded for clarity).

Real energy amount drawn from the grid to the meter/dispenser (home plus one DC charger event) is 162.712 kWh.

So I get a 17% delta this month.

For troubleshooting the most accurate intermediate data available is the energy supplied to the battery and that's obtained by reading CEC (from an OBD app) before and after charging. The difference is the actual kWh delivered to the pack. The readings will still be valid even taken some hours before and after the charge duration because the only periodic live load to the pack is aux battery charging and that depletion is minor in comparison to what you're adding.

I believe the accuracy of the BMS's current and voltage measurements are likely very good because the accuracy of the running SoC is entirely dependent on that, and it's DC. Those values would be integrated in real time by the BMS to add to accumulated kWh.

I charge at only 1.7 kW so losses will be somewhat higher but typically my battery pack receives 84% of the AC energy delivered. I've verified the AC energy measurement device by comparison with a true RMS DMM on a similar fixed resistive load and they concurred to 99%.

The car's "accumulated info" should use the same BMS hardware but for current leaving the battery. That would be affected by pack cycle losses which are 2% in my estimation.

I don't dispute your observations, however I'm simply tracking two numbers.

First number: what has the grid "given" to run the car.

Second number: what does the car say the energy spend actually was to propel it x km.

but typically my battery pack receives 84% of the AC energy delivered

And based on my (admittedly very low) total distance numbers of an 18% spread between "grid" and "odometer" numbers, I'm comfortable in telling people who are interested in the efficiency of my wife's Kona "to add about 18% to whatever the trip odometer tells you to figure actual energy usage".

 

[KiwiME]

Ok, that's fine, I didn't want to spend too much time digging through all those numbers.

 

[navguy12]

Feb 2021 results:




Raw data for 2021 (away from home recharge data photo missing):




Summary of costs as of 28 Feb 2021:



Total operating costs, per km (total costs minus capex costs):

$13.3014 - $12.6064 = $0.6950/km

 

[R P]

You should really separate your capital costs from your operating costs. Just take a fraction of the capital to represent the amortization amount for the time you own the car to add to your operating cost. That would make your final numbers look a bit more meaningful, esp that final Cost Summary box.

 

[navguy12]

You should really separate your capital costs from your operating costs. Just take a fraction of the capital to represent the amortization amount for the time you own the car to add to your operating cost. That would make your final numbers look a bit more meaningful, esp that final Cost Summary box.

Right now the cost is, as broken out above, 69.5 cents per km.

I do not estimate a fraction of the capital because the day the car is disposed of will result in a negative value being entered as a capital cost, specifically the actual selling price of the vehicle to the new owner.

Of course, at disposal, any disposal costs are captured as line item costs prior to the sale...such as Ontario used vehicle package and safety inspection.

I’ve been tracking my automotive costs on this fashion since 1997.

Once a vehicle is disposed of (always private sale, have never traded in) and the spread sheet is locked, it contains the true cost per km with actual depreciation captured at that time...not including opportunity costs of course.

 

[navguy12]

Mar 2021 results:








Summary of costs as of 31 Mar 2021:


Total operating costs, per km (total costs minus capex costs):

$12.2889 - $11.6442 = $0.6447/km

 

[navguy12]

Apr 2021 results:






Summary of costs as of 30 Apr 2021:



Total operating costs, per km (total costs minus capex costs):

$11.5831 - $10.9739 = $0.6092/km

 

[navguy12]

May 2021 results:









Summary costs as of 31 May 2021:



Total operating costs, per km (total costs minus capex costs):

$10.5468 - $9.9900 = $0.5568/km

 

[navguy12]

June 2021 results:









Summary costs as of 30 Jun 2021:



Total operating costs, per km (total costs minus capex costs):

$10.0085 - $9.4788 = $0.5297/km

Discussion:

Just like my TM3, when the monthly distance driven decreases (compared to other high distance traveled months) the difference between what the car indicates was used for propulsion versus what was actually drawn from the grid increases (compared to other high distance traveled months).

With only two EVs, the data set is small, but I will assume that the world wide EV fleet acts the same: "phantom" energy use becomes a larger factor with less distance driven.

 

[navguy12]

July 2021 results:









Summary costs as of 31 Jul 2021:



Total operating costs, per km (total costs minus capex costs):

$9.3868 - $8.8731 = $0.5137/km