If this has been answered in another thread I apologize. With an electric bike, speed and distance are not the only part of your performatnce equation. The other part is how much electrical assist you used. The other day I went on a 44 mile loop that I've done several times. It's a pretty hilly ride (for me). I deliberately used less boost than I had, and my average speed went down 2 mph. But I felt that the power I contributed actually increased. I have a Bosch Purion display, which tells me estimated mileage left at any given assist level, but that's a pretty inaccurate measurement. Is there anything that will accurately measure the charge used in a battery before or after the ride? It's a removeable bosch battery, so an external device would work.