I don't need credit for math.
You want to calculate mi/kWh (miles driven per kWh of battery depleted) in order to estimate your miles left in the battery. This assumes the driving conditions for the rest of your trip are similar to what you just drove.
You need to know:
USABLE battery capacity of the SE:
28.9 kWh
Start-battery %
End-battery %
Total miles driven
Assume you started with 100% charge and drove 100 miles, with an end-batt% of 20%:
You
USED 80% of the battery: In kWh you used
28.9 capacity x .80 =
23.12 kWh
The
miles/kWh = 100 miles /
23.12 kWh =
4.32 mi/kWh
Your REMAINING batt capacity is
28.9 - 23.12 =
5.78 kWh
RANGE LEFT would be mi/kWh x REMAINING capacity:
4.32 x
5.78 =
24.96 miles
TOTAL RANGE = 100 + 24.96 = 124.96 miles