I just took my first ride on my new BPM fat-tire (4 inch) with Ultra motor. It’s as fast as I hoped (26 mph on flat with throttle only). But the battery is draining rapidly. I rode it 7 miles on highest level assist, pedaling the whole way without throttle, on mostly flat ground and drained almost the entire battery (48v, 17a). I weigh 225 pounds. Am I doing something wrong or is this what I should expect?