I am sadly over 17 and a half stone at the moment and rode my bike yesterday for a leisure ride that turned out to be 28 miles when I got home.
I have a crank drive Yamaha Haibike of 2015 vintage with an original 400Wh battery. The bike has now completed 14,470 miles.
It was a very mixed ride, with a starter of about 6 miles of canal tow path, a mile of road, then the main course of off road single track routes around the North Downs that included one extreme steep and very direct technical climb of the North Downs escarpment and two other very steep and technical climbs as well as another difficult and very technical, though much shorter climb.
Also some great descents! Then another 6 mile country lane ride home with one very steep hill to get over.
I had 41% of my 400 Wh battery that is over six and a half years old left when I got home, so the total range of that over 6 and a half year old battery if I had kept using it the same way should have been 47.45 miles.
If I stopped at the end of the last paragraph that would be very misleading and the difficulty with any discussion about range.
I am at least in cardio vascular and leg strength terms fitter than the over weight 60 year old man I appear to be (Thank you regular cycling). I turn the assist off on gradients that allow. So the whole first section from home to the end of the canal tow path section used under 5% of my battery.
I use the eco assist level of the three I have, even on steep hills and only the middle assist level when I really need it. I needed it for The North Downs steep technical sections.
If I had put my bike in middle assist from the start of my ride yesterday I would have drained the battery completely in probably around 15 miles.
The truth is out there, but in relation to the range of ebikes somewhat elusive.