How long do the batteries last? What are the charging possibilities? Does one need to carry extra batteries?

These are the questions I would ask if I was considering e-shifting. Of course all of those are dependant on shifting frequency but it's sometimes hard to predict. On our last tour just last week we were doing a homeland tour and due to the peculiar geography and road conditions of ours we were doing hundreds if not thousands of shifts per hour. That has to have an effect on battery duration