E-Bike Range

The arithmetic

Range Is Battery Watt-Hours Divided by Watt-Hours per Kilometer

A battery's energy is its nominal voltage times its amp-hours: a 36 V, 20 Ah pack holds 720 Wh. Divide that by consumption in Wh per km or Wh per mile and the result is range.

Consumption is the only term that moves much on a ride. A 2021 test by Juiced Bikes put a 95 kg rider on a CrossCurrent X with a 780 Wh battery over five days of mixed riding, mostly in the lowest assist levels, at an average of 18.9 km/h (11.7 mph). The bike used 6.9 Wh/km (11.3 Wh/mi) and covered about 111 km (69 mi) on one charge. The same bike in its highest mode reached about 35 miles.

The worked example uses the Aventon Level.3, a Class 3 commuter with a 733 Wh battery (36 V, 20 Ah, LG 21700 cells). Aventon claims up to 70 miles for a 75 kg (165 lb) rider on flat sidewalk in Eco mode.

What drives consumption

Speed and Climbing Use the Most Energy

On flat ground a bike pushes against rolling resistance, which grows with weight and speed, and air drag, whose power grows with the cube of speed. On a hill it also lifts its total mass.

The table models one rider and bike at 100 kg total, a drag area (CdA) of 0.5 m² for an upright rider, a rolling resistance coefficient of 0.006 for a road tire, and still air on flat ground. The figures are total energy at the wheel, from the rider and the motor together; the battery supplies the motor's share plus drivetrain and motor losses.

• Speed: going from 25 km/h, the EU pedelec limit, to 45 km/h, the S-pedelec limit, raises energy per km about 2.6 times.
• Assist level: higher modes add motor power for the same pedaling, so speed and climbing rate rise and the battery carries more of the load. Juiced's CrossCurrent X covered about twice the distance in Eco as in its top mode.
• Hills: lifting 100 kg through 1 m takes 0.27 Wh at the wheel, so 1,000 m of climbing needs at least 273 Wh from rider and motor combined.
• Rider plus cargo weight: going from 100 kg to 150 kg raises rolling power at 20 km/h from 33 W to 49 W and climbing energy from 0.27 to 0.41 Wh per meter.
• Wind: a 15 km/h headwind at 20 km/h ground speed raises air drag power from 51 W to 158 W and total energy from 4.2 to 9.5 Wh/km.
• Tire pressure and tread: a soft or knobby tire that doubles the rolling resistance coefficient to 0.012 adds 33 W at 20 km/h. Bosch advises riding at the tire's maximum permitted pressure.
• Stop-and-go: each start re-accelerates the full mass. Bosch states that frequent starting and braking uses more energy than steady riding, and recommends starting in a low gear and a cadence of 60 to 90 rpm.

Cold and aging

Cold Weather and Cell Aging Shrink the Usable Battery

Lithium-ion internal resistance rises in the cold, so voltage sags sooner under load and the controller cuts off with energy still in the cells. The loss reverses when the pack warms.

Shimano rates its BT-E8036 630 Wh battery for discharge from -10 to 50 °C and for charging from 0 to 40 °C. Bosch gives the same 0 to 40 °C charging range and advises against charging in direct sunlight. A pack carried indoors between rides starts a cold ride warm and keeps more of its capacity.

Aging is permanent. Cells lose capacity with every full charge cycle, and faster when stored full, kept hot or fast charged. Shimano states that the BT-E8036 retains about 60% of its capacity after 1,000 full charge cycles. Battery warranties are written around the same kind of threshold: Bosch, Brose and Bafang have tied capacity coverage to 60% of rated capacity, and Yamaha in the US to 50% within 700 cycles. A pack at 60% delivers 60% of its new range under the same riding.

Range calculators

The Bosch Range Assistant Turns the Same Inputs Into an Estimate

Bosch eBike Systems publishes an online range assistant for its motors and batteries. Its inputs are the factors above: rider and cargo weight, season, motor, battery, cadence, road surface, shifter type, tire tread, assist level, terrain and riding style.

Bosch's published examples assume a 100 kg (220 lb) rider on a sunny day over poor roads with some climbing, on an Active Line motor. They work out to about 10 Wh per mile on a single battery and slightly less on a dual setup. Riese & Müller links the same calculator from its DualBattery page.

Standards

No Mandatory Range Test Exists in the EU or the US

Makers choose their own test conditions for range claims. The closest thing to a common method is the voluntary R200 test from the German bicycle industry association ZIV.

ZIV published R200 in August 2018, developed with Bosch eBike Systems, Accell Group, Shimano and the test lab Velotech. It runs on a test bench and normalizes every pedelec to a 200% support factor: the rider supplies 70 W and the motor adds 140 W. The other conditions are 100 kg total mass, 20 km/h average speed, 60 rpm cadence, a touring riding position, hilly terrain, poor asphalt, medium start-stop frequency, a light wind, lights off and a new battery and drivetrain. The result reports battery capacity and energy consumption, so bikes can be compared on Wh per km. ZIV and Bosch announced in 2019 that they were working with DIN to publish R200 as a DIN SPEC.

Since January 2020, S-pedelecs and other EU L1e-B, L2e and L6e vehicles are range-tested on the World Motorcycle Test Cycle (WMTC) as part of type approval. R200 continues for 25 km/h pedelecs.

EN 17404:2022 is the European safety standard for electrically power assisted mountain bikes (EPAC MTB). It builds on EN 15194, the general EPAC standard, and contains no range test. In the US, UL 2849 covers e-bike electrical systems and UL 2271 covers light electric vehicle batteries; both address fire and electrical safety, and neither sets a range test. The Safe SPEEDS Act (H.R. 7839), introduced in March 2026, would have the Consumer Product Safety Commission set e-bike classes and labeling rules, and does not address range.

Claims and tests

Maker Ranges Span a Factor of Two, and Tests Land at the Low End Under Hard Riding

A claimed range is a consumption figure the maker picked. Range spans in spec sheets show how wide that choice is.

The BIKE magazine test also shows that a battery delivers less than its label: the 725 Wh BMZ pack took 712 Wh to recharge from empty. In a 2019 bench test of five motors by the Swiss consumer magazine K-Tipp, a Yamaha PW-X bike with about 500 Wh covered about 200 km on the flat in its lowest assist and about 22 km up a 6% grade, a ninefold spread on one battery.

Range extenders and dual batteries

Second Batteries Add Watt-Hours in Fixed Steps

A range extender is a small second pack, usually in a bottle cage. A dual-battery setup carries two full-size packs. Both add range in proportion to the watt-hours they add, less the energy spent carrying their weight.

On the Bosch figures above, two PowerTube 625 batteries give an estimated 140 miles against 65 miles for one, slightly more than double, because consumption per mile stays about the same.