Correct me if I misunderstood (or read things too literally), but you're saying you stopped more than 8 times in a 500 mile trip? That seems like a lot, especially if they were for recharging. But I don't know the charging rate so maybe it was a case of many short sessions vs. 1 or 2 long ones?

Note: I got >8 because you said most stops were 10-min and then listed 4 stops longer than 10-min.