I travel 10.5 miles to work, 21 miles round trip. I use a 750wh 15.6ah battery. If I pedal in the higher gears (6-7 on a 56T chainring) and travel 20-24 mph (assist levels 5-6, controllers probably vary), I have to charge after every 3-legs or 31.5 miles. I just doubled my travel distance per...