Running out of battery is every e-bike user's nightmare - well if you have a Bosch-assisted e-bike, you can accurately predict how far it will take you using the Range Assistant feature on their website.
Input your predicted average speed and riding mode, from 'eco' for partially assisted riding to 'turbo' for full assist. You then fill out a more detailed form, giving your weight, predicted cycling cadence, type of eBike you ride and what environment you'll be riding in.
It's interesting to see how different terrain and conditions affect your battery life - for example, when we selected 'mostly good ashpalt' for our riding surface using a PowerPack 300 and Performance Line Speed Drive, the calculator predicted 66.2km of riding. If we changed the terrain to 'dirt forest and field paths', the distance goes right down to 46.9km.
Other things that affect the range greatly are wind conditions, the elevation of your ride and how many times you have to start the drive up again. While the average rider might not have all this info at hand (especially if weather conditions are changeable on the day) the Bosch Range Assistant is more suitable as a rough guide rather than absolute proof of how far you can go on your journey. Always make sure you make a conservative estimate concerning battery life if you need assistance for the duration of your ride!