Uneven battery use

Ah, “mostly level ground.” That could be interpreted either to mean no appreciable elevation change, or not many hills, or both, so not sure.

 

That’s probably a big piece of it...

 

And we are trying to tell you that measuring "actual battery percent charge level" really IS mostly a guess.......unless you have some really expensive equipment which is not present in your average car.

 

Hmmm... So why would that be hard? They know very accurately how many KWh they’ve pulled from it, and how many they charge into it each time.

 

Mostly because it is almost impossible to accurately determine what the usable CAPACITY of the battery is at any given time.
That typically varies with age and temperature and manufacturing quality.

 

I’ll buy that for long-term battery capacity, but they know how much they charged into it last time it was charged, and how much they’ve discharged from it. There will be a certain amount of self-discharge, but that’s pretty small assuming that the time from charge to discharge is short.

It’s certainly at least a vastly-more-precise science than estimating how many more miles you get on the current battery charge (the GoM).

 

i would think percentage would be more accurate than miles available, since that can be affected by driving conditions.

 

Indeed.

 

Another reason I like using my ol' trusty, dusty ScanGaugeII for SOC readings. Of course, it's only as good as the x-gauge script written for it; which is pretty darn accurate on my C-max.

 

SOC % shown on the MID is perfectly linear with what ECU reports on Hybrid Assistant. 100% SOC on MID is 83% SOC on ECU, and 0% SOC on MID is 14% SOC on ECU. See my comment #8. I have not tried ScanGaugeII or any other app that might show that data, but as long as they are getting the data from ECU, I would think they all show the same SOC wouldn't they?

I agree with @mr88cet all of in and out (kWh) of the traction battery is known by the ECU, so reporting SOC % should be accurate.

 

If I were choose just one reason, it would be this^

I don't know about other people, but I'm not particularly good about judging elevation changes on roadways unless they get really obvious, so I would likely consider anything <5% grade to be "flat".

I pretty much run HybridAssistant every time I drive my Prime and I've learned that consistent driving is extremely hard. Even in the same flat, no-traffic drives, I can be wildly inconsistent in how much I accelerate, brake or even cruise. And the Prime is very. very sensitive to these changes.

 

I'm in the same park as the two comments above mine @noonm and @Salamander_King

It's only 3.6 miles, and should be easy to retrace your route almost exactly once, twice or as many times as it takes for you to find the gauges that will show you without any doubts left exactly what is happening during the elevation change in both directions.

Here are two pics taken 3 Oct 2019 . I have elevation changes of
beginning ----103.00 m / 337.93 feet
main road ----111.00 m / 364.17 feet
3.1 miles down - 76.00 m / 249.34 feet


chargepoint -------- 75.00 m / 246.06 feet
back to side road - 11.00 m / 364.17 feet
back at beginning - 103.00 m / 337.93 feet

elevation data from https://www.daftlogic.com/sandbox-google-maps-find-altitude.htm

The best description I have of this mornings 2 trips are
41.5 miles EV trip one
full charge at chargepoint charger
3 miles back to the beginning.
I have other ( mostly boring as hell ) photos from these two trips, of various gauges from the Multi Informational Display as shown above
and some others from the 2017-2019 Prime Plus 7 inch Display,
116 including the two above.

Speed is actually the biggest factor in EV and EV auto battery use and range.
My speed was 44 mph and under, mostly under, way under.
Edit:Check that, going up hill can be. If the elevation change is great enough, that can Trump speed for the biggest factor in EV range. Even going up a very long and steep incline at very slow speed can be more kWh intense than going faster on the flat. But the amounts and angles make the blanket statements dead wrong at times.