I want to tour with my e-bike so the range the battery will provide is a very important factor for me. Unfortunately, e-bike batteries can be the most confusing component of the bike. For example, my battery is a 48 Volt, 840Watt Hour, 17.5 Amp Hour battery. But what does that mean? While Bafang USA Direct states that it provides, “Up to 840-watt hours for an incredibly long range,” that really isn’t much help.
E-bike manufacturers tend to focus on watt hours. However, range cannot be determined by simply dividing a battery’s watt hours by the watts of the motor. Range will vary widely based on many factors including type of bicycle, rider posture, total weight, tires, riding speed, pedal assist level, terrain, riding surface, prevailing winds etc. So while my battery might provide power for an hour running full blast on throttle, it may also provide assistance for 100 miles or more on assist level 1. Only experience will tell the true range of my bike and battery.
However, I have found a very useful tool for estimating the range of a motor and battery combination. While the site is Bosch specific, it can provide an idea of what range a motor and battery can provide under various conditions. Check it out at https://www.bosch-ebike.com/us/service/range-assistant/ or click here.