Range is one of the most important questions when it comes to electric bikes. After all, these vehicles are often used as a replacement for cars and you need to know that you’ll be able to get to and from work or running errands on the available battery power.
There are a lot of different factors that can influence the exact distance your electric bike can give you, and not all of them are entirely predictable. The weight of your bike is one major factor, but so is your weight and the weight of any cargo you might be carrying.
There’s also wind resistance. An aerodynamic electric bike might not slow down too much if you’re biking into a headwind. But a bike that’s loaded down with front and rear baskets filled with grocery bags will probably be impacted.
Still, even with all of those inconsistencies, you can get a pretty good estimate of your bike’s range. Here’s how.
Calculate the Watt Hours in Your Battery
The first step toward figuring out your bike’s range is to see how much power its battery has to offer you. Unfortunately, neither amps nor volts are a good measurement of range.
You’ll need to convert the volts and amps on your electric bike’s setup into its watt-hours. Watt-hours are literally a representation of how many hours of battery use you have, based on the number of watts used in an hour.
Find the voltage listed on the battery. Usually, you should be able to see the volts directly on the battery, otherwise, look at your user documentation to see if it’s included there.
Next, you need to know Amp-Hours capacity, also listed as Ah, for your motor.
Multiply the two together to get your battery’s watt-hours. So, a bike with 48V and 12.8Ah gives you 614.4-watt-hours for that bike.
Using Watt-Hours to Estimate Your Bike’s Range
The next thing you need to do is to estimate your watt-hour use with your bike. Your watt-hour use will vary quite a bit depending on your speed, weight, and other variable factors on the bike.
A good way to start is to use a base estimate of use. Most people use an average of about 20-watt hours per mile on their bike if they’re being a little conservative with the battery.
That’s a bare estimate of course. If you’re using a lot of engine power, you’ll use more watt-hours per mile than you will when you’re pedaling a lot. Uphill travel can also cause a lot more battery drain.
But, using a 20-watt hour per mile average you can get about a 30-mile range out of a bike with 48V and 12.8Ah.
Just divide the watt-hours by the watt-hours used per mile to estimate your total range.
Getting a More Accurate Range Estimate
Of course, that is a range estimate based on average use by cyclists of varying weights and skill levels and in a wide variety of environments. If you want a more accurate estimate or have discovered that the method we’ve described isn’t giving you a good estimate, it’s time for some testing.
The most accurate way to test your bike’s range is, of course, to use the whole battery and see how far you get.
While that’s an option, it might not be ideal if you have a more powerful battery and don’t want to spend a lot of time testing.
Still, it’s probably the single most reliable option. Try to recreate the heaviest use scenario for your bike.
So, if you’re going to use your bike for grocery store runs and other errands, you’ll want to put your bike racks or baskets on the bike and load it with some cargo for testing.
We recommend that if you’re going to test your bike this way, stay close to home. Ride in circles in your home neighborhood so that you’re never so far from home that you can’t pedal the rest of the way comfortably.
Another way to test, if you have an eBike that shows your battery use is to use half the battery, track the distance you’ve traveled, and double the total for your final range estimate.
Unfortunately, even testing your eBike directly this way is only going to give you a rough estimate because of the day to day changes in conditions outside and the state of your bike itself.
Common Factors that may Change the Range of Your Bike
There are tons of different factors that can affect the total range of your bike and can make range estimates tricky. You can account for some of those changes by raising or lowering your range slightly, but it’s difficult to get a precise estimate because of these variables.
Tire pressure can have an incredible impact on your bike’s efficiency. Low tire pressure can drain your battery incredibly quickly because your tires have more friction with the ground and don’t recover as well as you move.
If you know that your tire pressure is lower you should adjust your range estimate lower because you’re going to be using a few extra watt-hours every mile, even if you’re pedaling a lot.
One way to mitigate this is to check your tire pressure every couple of rides to make sure it stays more consistent.
Battery Quality and Age
Your batteries can also have a big impact on your range based on the efficiency of the battery itself. A battery that is starting to lose its efficiency may not be able to hold it’s full charge and may lose more energy over time than a battery in top condition.
Name-brand batteries will typically have better performance and last longer than no-name batteries, so look for a bike that uses a higher quality battery if you can afford it.
Weather conditions can also have a huge impact on your bike’s efficiency. Wet conditions will increase the friction on your bike and demand just a little more energy to handle. The wind is another important factor to consider.
A good tailwind may improve your bike’s efficiency, while a headwind will slow you down and decrease efficiency.
Lastly, mud, snow, and other high-friction terrains will have a huge drain on your bike’s efficiency and can drastically reduce range.
Level Ground Vs Hills
The last thing to consider is how level your route will be. Flat ground performance will be very different than a route that’s almost all uphill, or almost all downhill.
Fortunately, hill performance is a little more predictable than some of these other factors. With a little experience, you’ll be able to estimate your bike’s range over hilly terrain with much greater accuracy.Last updated on: