Determining how far an e-bike can travel with pedal assistance falls in the very nebulous part of the dark arts. There are outrageous claims and then rarely, those that are a little more conservative, but all the claimed kilometres are always prefaced with the “up to” – this seems to cover all manner of sins. The claims have been getting worse (higher) as competitors try to outdo each other in the benefits of their specific e-bike.
So let’s get a little more scientific with it, and understand the basis for these claims and also what to look for in terms of range for your next e-bike.
The factors that affect the range your e-bike will travel on a fully charged battery depends on the following factors, in rough order of decreasing importance
- Amount of rider input
- Weight of bike, rider and luggage
- Wind Conditions
- Outside temperature
- Road Surface type
- Number of times you stop / start
- Battery Capacity
- Motor type and efficiency
- Controller type and efficiency
- Assistance level
- Tyre pressure
- Age of battery
- Integrated lights turned on?
- Wheel size
- Tune of the bike, as in has it be serviced?
With so many variables, the one area that is often looked at is Watt/hour rating of the battery. This indicates how much capacity it has and theoretically how far you can potentially ride – with all other things being equal. However things are rarely equal, and as we can see from the list above there are a number of things that affect the performance, including other aspects of the e-bike system as well as the configuration of the bike.
It is also worth mentioning that bigger W/hr is not always better and often it is not best to over spec the battery. A big battery is very heavy and consequently the bike is almost useless without power assistance. It can be easier to have a slightly smaller battery that you can charge more often at home, or in the office easily, most ebike system brands sell chargers separately.
Also batteries cannot just be judged in terms of W/hr. Batteries can vary in quality with some only built for 500 recharge cycles (Entity is based on 2000 cycles). When they hit this number the capacity typically drops to around 70%. Hence it is better to have a smaller high quality battery than a large poor quality one.
Thankfully, a European standard that is being written at the moment that will clear up a lot of these anomalies, and to provide a clear basis on what kilometre range can be claimed.