You're going to have to figure this out for yourself pretty much. Your local terrain, wind, how much assist you use, ambient temperature, battery care, all play a part in the range you'll get. Keep an eye on the battery bars and make sure you have enough juice to get back. It takes some practice, but it's not too hard.
I can usually count on 25 to 35 miles, but I use a lot of PAS. I like to go fast. I've done 40 miles one charge, but I'll probably carry a spare battery if I plan on going over 30 miles. I've gotten less than 15 miles in soft sand.
TT
