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Destination SoC Anomaly

Yesterday I was driving from the Barstow SuperCharger to the Needles SuperCharger, a distance of 148 miles. I had the nav system programmed for Needles and it estimated that with my starting SoC of 97% I should arrive at my destination with 43% SoC. I was driving with AP enabled and my speed was set to 70 mph and after a few miles my Destination SoC settled at 42% -- less than what I expected it to drop so that was a pleasant surprise.

My Destination SoC consistently sat at 42% for a little over 100 miles until I was about 40 west of Needles. At that point I encountered some bridge construction where the eastbound lanes were closed and traffic was routed onto a westbound lane -- a pretty common occurrence during construction season. What happened to my nav system was anything but expected.

As I was in the westbound lane, heading east, the nav system re-calculated my route, twice, and adjusted my Destination SoC to 32%. A 10% immediate drop! This got my attention since it's a pretty desolate area so I monitored my Destination SoC very closely. Over the next 10 miles it dropped to 29% even though my current SoC showed no corresponding drop.

My Destination SoC remained at 29% for the rest of the trip (about 30 miles) but I arrived at the Needles SC with 42% SoC which was the original estimate. Even as I backed into the charging stall the Destination SoC still read 29%. So what happened here? Anyone else ever see this type of behavior? My software is v8.1 (17.14.23)
Clearly it added the distance you'd have to drive west to the nearest U-turn to your recalculated route and recomputed the energy calculation based on that distance. It seems the energy estimator doesn't change its starting point unless the route is recalculated. You can see this in the energy graph -- it always draws a line that starts at the beginning of the graph, through the point representing the distance you've gone. When you got to Needles, the energy page didn't know that. It assumed you still had 40 miles left to go. To test this theory: was your graphed distance on the energy page at the far right when you arrived, or were there still 40 or so miles to go?
The first re-calculation told me to make a u-turn at the next exit (which was 17 miles west) and I assumed it was because I was in the westbound lane although it struck me as odd that it didn't take into account that I was actually heading east.

The second re-calculation occurred when I re-entered the eastbound lane. It then computed my trip from that point and the nav map showed my current position as the starting point -- not Barstow. The energy graph showed the correct SoC for my new starting position with 32% as my destination SoC -- although that did drop to 29% and stayed there.

As I drove, the energy graph correctly showed my progress and distance from Needles but the destination SoC never varied from 29%. When I arrived in Needles the energy graph showed 0 miles to go and a destination SoC of 29% even though my current SoC clearly showed 42%.