Is my car over-charging the battery?

[GASKIKR]

I always suspected that my car was over-charging the battery on the standard charging mode. Basically, a standard charge is supposed to put 35 kWh into the battery. Knowing that the extra kWh's of an extended range charge aren't represented on instrument cluster you can deduce how much "extra" charge you have by using the car's consumption report (the one that comes up when you turn the car off) and comparing it to the amount of miles driven until the first bar is "consumed". So here's what I've come up with:

My first bar was consumed after driving 11.7 miles. That distance was driven in 2 trips of about 5.8 miles each, the first came in at 3.9 m/kWh and the second was 3.6 m/kWh. Average consumption is 3.75 over both trips so 11.7 / 3.75 = 3.125 that's almost 1 extra kWh. Now, I know regen counts for some of that extra energy but I was driving on pretty pancake-flat roads of OC. I'm also assuming that any recovered energy from stopping at intersections would be entirely negated by the extra consumption of accelerating each time. The reason I bring this up is because I've noticed that the first bar lasts longer and almost always gets me about 9 miles whereas the next bars will get about 7 miles each. So I'm wondering if the car's charging to maybe 36 kWh's instead of just 35.

I know it's minutia and trivial but I'm curious to find out if anyone else has noticed this. If so, are there any ideas on the cause?

 

[smkettner]

11.7 sounds normal to me. That first bar seems to hold a bit more than the rest.

 

[TonyWilliams]

Fuel Bars

New car - loss of 5.1% SOC per fuel bar until 48.1% SOC

12% degraded car at 50,000 miles - Loss of 5.4% SOC per bar until 51% SOC, then 4.5% SOC with variations per fuel bar below 51%

35kWh / 41.8kWh = 83.83% of usable capacity when new

Full "extended" charge - 96.5%- 98% SOC, 4112mv-4114mv per cell

When car is turned on to READY, voltages drop to 4100-4106 with A/C pump running.

Normal charge - 88.9% (12% degraded car), SOC 84% (new car)

FUEL BAR SEGMENTS @

-------12% degraded -- New

16 gone - 83.4% ------ 78.7%

15 gone - 78.0% ------ 73.6%

14 gone - 72.6% ------ 68.5%

13 gone - 67.2% ------ 63.4%

12 gone - 61.8% ------ 58.3%

11 gone - 56.4%------- 53.2%

10 gone - 51.0% ------ 49.1%

9 gone - 46.4% ------ 43.7%

8 gone - 41.9% ------- 39.5%

7 gone - 37.4% ------- 35.3%

6 gone - 32.9% ------- 31.1%

5 gone - 28.4% ------- 26.9%

4 gone - 23.9% ------ 22.5%

3 gone - 19.4% ------ 18.3% (Low Battery Warning)

2 gone - 13.9% ------- ----- (Very Low Battery)

Flashing gas can - 12.9%

LO - 8.4%

1 gone - 7% SOC (Climate Control Limited)

Turtle - 2.9%

*********

Extended Range kWh and charging times from a full "Normal" charge

Assumes North America 240 volts. Add 15% more time for commercial 208 volts.

------------------------------ 40 amps -------- 30 amps

New battery --- 6.8kWh - less than 60 min ---- 80 min
10% degraded - 4.8kWh - less than 45 min --- 60 min
20% degraded - 2.8kWh - less than 30 min --- 40 min
30% degraded - nil

 

[TonyWilliams]

The simple answer to your question is that Tesla controls the battery and Toyota designed and programmed the display with which you're basing your observations.

I can assure you that the odds of Tesla allowing the battery to be overcharged are probably greater than one in 1 million. The odds of either the GOM or the fuel bars being AFU is 100%.