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Electric Bike Battery Range in Real-Life Conditions

One common question we receive is about the range of our Electric Tricycles.

On our website, we provide the real-life range, which means, we test the tricycle under maximum load conditions. If the tricycle has a payload capacity of 150 kg, we load it up to that weight. The tires are properly inflated to the recommended pressures, and the battery is fully charged for the test. This way we know the range that we publicise is achievable by anyone, anywhere and the range is quoted without any caveats.

Although our tricycles have pedal assist, for the purpose of determining the true battery distance, the pedals are only rotated to engage the pedal assist function without any contribution to the range extension.

Some manufacturers make claims of 80 km, 120 km, or other arbitrary numbers that they simply “make-up”, but the reality is, the range of a tricycle is determined by the motor size and battery capacity, which have set outputs dictated by physics. There is no magical way to make a tricycle go three or four times further than what it can based on these fundamental parameters.

We have received feedback from disappointed customers who purchased tricycles advertised elsewhere with a 100 km range but could only achieve 35 km, the importer is ignoring their requests as to why their tricycle is not making the advertised range, and they reach out to Trike Bike in desperation for assistance.

This feedback has prompted us to address the topic again in this newsletter, because it is something which comes up over and over.

For those interested in the technical details, it is quite straightforward to calculate the real-life range instead of relying on exaggerated or untruthful advertising claims.

In order to calculate the potential distance covered by the 3-wheel Sobowo FAT Trike Bike, we rely on a set of established values and also make a few assumptions.

The tricycle is equipped with a peak output 500-watt motor and a 48V, 15 Ah battery, which offers a consistent total discharge energy of approximately 760 Wh. These values remain constant and unchangeable.

Assuming a speed of 25 km/h on level ground (the maximum speed limit for a pedal assist vehicle in Australia), ridden with a payload of 150 kg, with properly inflated tires, then we can calculate the expected distance by considering the motor’s power consumption and the battery’s energy capacity using SCIENCE not advertising fluffery.

(Nerd stuff following, skip to the end for the summary if your eyes glaze over)

 

Given the following information:

Power (W) = 500 watts

Battery capacity (Wh) = ~ 760 Wh

Speed (meters/second) = 25 km/h = 25,000 meters / 3,600 seconds ≈ 6.94 meters/second

 

To calculate the distance, we’ll use this formula:

Time (hours) = Distance (meters) / Speed (meters/second) / 3600 seconds

Energy consumed (Wh) = Power (W) x Time (hours)

Distance (meters) = Speed (meters/second) x Time (hours) x 3600 seconds

 

To find the distance:

Time (hours) = Distance (meters) / (6.94 m/s) / 3600 seconds

Energy consumed (Wh) = Power (W) x (Distance (meters) / (6.94 m/s) / 3600 seconds)

Energy consumed (Wh) = Power (W) x (Distance (meters) / 25.08)

Distance (meters) = Energy consumed (Wh) x 25.08 / Power (W)

 

Knowing these values, we can now calculate the distance:

Distance (meters) = 760 Wh x 25.08 / 500 watts ≈ 38.23 kilometers

 

Summary

Therefore, with the standard 760 Wh battery, the tricycle can go approximately 38.23 kilometers when ridden at a constant speed of 25 km/h with a 500-watt motor and 15 Ah battery.

Remember that this is a calculation “worst case” estimate, and actual results will vary based on various factors like, wind, weight of the rider, temperatures, tyre pressure, battery condition, hills and so on.

Our own testing of the Sobowo FAT Trike Bike has given better results than were calculated. A ride I completed recently was able to achieve 56 km in distance, this was a ride from our office to the Gold Coast Seaway and return utilising mainly bike paths and footpaths. Because there were a lot of stop and starting to cross different roads and the speed was probably an average of around 18 to 20 km/h then the distance travelled was further than what was calculated. If you were riding at say 60 kgs rider weight then the distance would be further again, if you added a bit of pedal power to assist the tricycle then you would add several more kilometers and so on.

Would a similar specification tricycle with the same size battery pack and motor size ever get to 120 km distance as advertised by some importers, absolutely not!

Physics is the one constant factor in the world that can’t be cheated.

 

In an upcoming post I will work out the best speed to ride to get the longest distance travelled. This will be interesting because I know power consumption at 25 km/h is more than double than at 16 km/h.

Will the tricycle cover twice the distance by going slower ?