One of the most common questions we get is how to calculate the geographic range of an electric bike. In essence, how far will an ebike go before it runs out of battery power.
If you’re in a rush and just want to use the calculator, scroll to the bottom of this page. However, if you want to know what goes into calculating the potential range of an electric bike, keep reading.
First, a little myth busting. First, all the electric bikes we carry can be ridden like conventional bikes, by pedaling and using the gears. There is no drag from a turned-off motor. Ebikes tend to be about 15 lbs heavier than standard bikes, due to the weight of the motor, battery and controller, which could affect your hill climbing ability.
The lithium-ion battery is the fuel tank for your ebike, not unlike the batteries that power your cell phone and laptop computer. Also like the batteries powering your personal devices, ebike batteries will not last forever, usually after about 1,000 charge cycles. For the average rider, it takes about 2 years to charge and discharge an ebike battery 1,000 times.
Non-Electrical Factors that Affect Electric Bike Range
There are many variables that affect ebike range, including the bike design of bike, rider weight and riding style, terrain, weather, surface moisture, tire inflation.
Bike Design & Maintenance. Electric bikes, like conventional bikes, come in many flavors. You have fat tire mountain ebikes, small folding ebikes, and laid back cruiser style ebikes. There are several key factors in bike design that affect range.
First, the weight of the bike is a major factor, but also the width of the tires. Fat tires, for example, have more surface area in contact with the ground, and more traction compared to a road bike with narrower tires.
Second, it’s important to note that a poorly tuned and maintained ebike will have a shorter range than a properly maintained vehicle. Low tire inflation, poorly aligned gears and brakes, and high wind resistance due to a lack of aerodynamic design will all contribute to reducing the range of an ebike.
Payload. The weight of the passenger and any cargo will also have a dramatic effect on ebike range. All things being equal, a 225-lb rider with a fully-loaded trailer will place a much higher demand on the battery than a 125-lb teenager with a fanny pack. The distribution of the payload on the bike will also affect range, especially if a bike is unbalanced due to the rear rack placement of the battery.
Weather & Terrain. Headwinds and wet roads each will reduce the potential range of an ebike. Likewise, how hilly your ride is, and if you go off-road on gravelly trails will impact how far you can travel on a single charge.
Electrical Factors that Affect Ebike Range
All electric bikes have 3 essential components that set them apart from a conventional bike. These are the motor, the controller and the battery. Each of these electrical components plays a critical role in the performance of an electrical bike, and if any of them is not working properly, it can adversely affect your ebike range.
We use watt-hours to measure the energy capacity of a battery pack, and this will help you figure out how long you can ride your ebike before fully discharging the battery. But before we get into watt-hours (symbolized Wh), let’s first review what a watt itself is.
A watt (W) is a unit of power, and power is the rate at which energy is produced or consumed. Think of watts as a measure of electrical flow. Does an electrical device need a big flow or a small flow to work? For example, a 100W light bulb uses energy at a higher rate than a 60W bulb; this means that the 100W light bulb needs a bigger “flow” to work. Likewise, the rate at which your solar energy system “flows” power into your home is measured in watts.
A watt-hour (Wh) is a unit of energy equivalent to one watt (1W) of power expended for one hour (1h) of time. A watt-hour is a way to measure the amount of work performed or generated. Household appliances and other electrical devices perform “work” and that requires energy in the form of electricity. Utilities typically charge you for electrical energy by the kilowatt-hour (kWh), which is equal to 1,000 watt-hours.
An ebike battery is measured by its voltage (V) and amp-hour (Ah) rating. To calculate the Wh of an ebike battery pack, we simply multiply its V and Ah to get the Wh.
- A battery rated at 36 V and 11.6 Ah will have a 417.6 Wh capacity (36 x 11.6 = 360).
- A battery rated at 48 V and 21 Ah will have a 1,008 Wh capacity (48 x 21 = 1,008).
On average, it's been estimated that the average ebike battery will yield one (1) mile of travel for every 20 Wh of energy.