As you drive and it gets tight, the car will warn you by suggesting to stay below a certain speed to make it to your destination. It happens when the predicted arrival is 5%. At this point the car switches it's calculation to the suggested lower speed. We are all familiar with that.

What most people don't know is the same behavior is happening when you charge. It will actually

*start*calculating with a slower speed. Once it's at 5% arrival or higher, it switches to normal speed. Not suddenly of course. It does so gradually.

It is a little difficult to explain, but below is a timelapse video that shows it really well. As you charge, the trip graph goes up. Once the arrival percentage hits 5% the calculation transitions from using a lower speed to normal speed. Note how it shows 5% arrival when the battery is at 81%. While it continues to charge it uses a faster and driving speed as a basis. The battery reaches 95% while the arrival is still at 5%. At this point, for the purpose of calculating the prediction, the normal driving speed is reached and now the arrival percentage goes up with the state of charge. If you watch the video it becomes very clear.

What does that mean? If you are charging on a road trip, never leave when arrival percentage is 5% or lower. Always wait for it to be at least 6% or higher to make sure the calculation is assuming normal driving speed. If you leave at 5% (or lower) you are going to have to do the entire trip with a reduced speed to barely make it.