Range depends on hills and how much you need to use the electric. On serious climbs / mountain passes, you can regenerate about half what it took you to get up on the downhill. You can't regenerate coming down small hills because you would come to a stop. My husband with COPD & lung lymphoma, a new hip, and 2 new knees rode the western half of the TransAm (Oregon coast to Colorado) on his Trek FX+. We averaged 43 miles a day, longest day was 71 miles. Only wore the battery completely down once, just as we arrived in town. It was dark and Don was using electric to keep the lights on. Even when the battery ran out, he was able to keep the lights on by gearing down really low and putting it in regenerate mode. In my journal, I kept a log of how many bars of electric he used each day (Trek's cyclemeter shows 8 bars of electric when fully charged, Don used anywhere from none to all 8 bars depending on the day's ride):
http://bicyclelife.topicwise.com/doc/yumadons1