When the power is lost on an electric bike or the battery pack is completely consumed, the bike will no longer function as an electric bike and the rider will have to pedal and roll the bike manually. This can make the bike feel heavy and difficult to maneuver (source: [Cycling Weekly](https://www.cyclingweekly.com/news/product-news/electric-bike-batteries-everything-you-need-to-know-235153)).
Before going on a long trail, you need to make sure that the batteries of your electric bike are full and all set for the long path.
If the power lost on the e-bike or the battery has run out, you can still use the bike but without the throttle.