Driving History Miles/KWh

[OhioTodd]

Since Ford has taken the Driving History out of the Ford Pass functions, I've been thinking about a way to accompish the same thing. I have one of the OBDII thingies and using the Scar Scanner app's Data Recording function. I was wondering if there was data there I could use. Well, it records lots of data that would be useful. It samples in intervals of roughly 0.1 seconds. It has distance traveled, HW Energy to Empty (effectively available KWH), HVB SOC % and HVB SOC % Displayed. There's other useful information like interval speed, interval HVB Power. Having used spreadsheets a lot in my professional career, I wondered if I could use that data. If the data would work, the Miles/KWH should be easy. Just use distance traveled divided by the difference of HVB Energy samples: Max HVB ENergy to Empty - Min HVB Energy to Empty). I also calculated the Miles/% SOC the same way. I used a Pivot Table to summarize. The result for a recent trip was as below. On this trip, the Trip energy was on the car was showing about 3.1%. So, that raised an interesting question: why does the full trip data of distance traveled divided by KWH used not equal what the car displayed? I noticed the same thing when there was a driving history. I've done this with several trips, and it seems like the Miles/KWH that shows in the Trip Energy display is the same as uMiles/%. The driving history list usually showed a higher number than what was displayed for an individual trip and it also looked like Miles/% as I recall. For any other Excel geeks out there, I used a Pivot table over the Car Scanner's exported data to do the summary in the data below. It would be pretty easy to do the same just by using min and max for each of the columns in the data. One other hint is that from the Car Scanner to get the data in the simpler format I used the CSV2 format when I exported the data.
It makes me wonder if this would be a better calculation of the typical trip energy usage than what shows at the end of a trip before you shut off the car, especially since the Driving History is no longer available. Any comments on the method and why the summarized data differes from the trip energy display would be interesting. Maybe some of the other techie geeks out there will find this a useful method to accomplish what the Driving History display in the Ford app used to provide.

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[Kevstone]

Sorry if I am late to the 'Ford maths' party but if you guys have the same trip display as us in the UK you will know the averaging function is complete rubbish. I'm not surprised by any calculation errors any more. Bring on the spreadsheets!

 

[OhioTodd]

So, do you think my algorithm is more accurate? I suspect the Ford built-in averaged some set of intervals and doesn't take into consideration the actual distance and KWh usage of each interval it uses or the total trip distance divided by the total trip power usage. I don't have the old data, but I think that when I saw what was in the Driving History, it had the distance and the KWh used and the miles/KWh was a correct division of that calculation but was 10%-ish off of what the Trip Energy function displayed at the end of a drive.

 

[Runningslow]

What is your battery degradation % reported in the scanner app? I wonder if the battery SOC is the absolute SOC and the displayed SOC takes battery deg into account. Total guess on my part.

 

[Teslaeata]

State of charge on dash as % always matched the SoC on OBD reader for me when checked, save for rounding up within a %age.

However, I didn’t think SoC represented degradation. Isn’t that SoH State of Health?

On OBD reader my SoH is 96% at 87,000 miles after c22,000kWh of charge power, c5,500kWh of which is from DCFC charge points.

 

[OhioTodd]

My battery State of Health shows 99%. My Mustang is only 4 months old. So, little degradation for me should be about right and wouldn't make any difference if it was factored in. I'm impressed that you have kept track of your total DC charging vs overall total.

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