How to Actually Calculate Leisure EV Range: The Complete Chain from Battery Wh to Real Kilometres

1. Why "Rated Range" Always Falls Short

The most common complaint from overseas customers is: "You claim 100 km, but I only get 60." In most cases this is not false labeling but a mismatch between rated conditions and actual use. Rated range is typically based on: flat road, single rider, 25℃, low constant speed, new battery, correct tyre pressure. Any deviation in real use reduces range.

The best way to earn customer confidence is not to argue about numbers but to provide a recalculable calculation chain.

2. Step One: Determine Genuinely Usable Energy

Battery nominal capacity: Wh = Voltage (V) × Capacity (Ah)

Example: 48V 20Ah = 960Wh.

But not all of it is usable:

• Depth of discharge (DoD): To protect battery life, daily use should not fully discharge. Lithium typically 80%–90%; lead-acid recommended no more than 60%–70%;
• Low-temperature derating: Lithium usable capacity drops noticeably below 0℃; at -10℃, 15%–25% derating is common (varies by cell and BMS strategy);
• Ageing: After 500 cycles, capacity typically shows perceptible degradation.

At 80% DoD: 960 × 0.8 = 768Wh usable energy.

3. Step Two: Efficiency Losses from Battery to Wheel

Energy passes through BMS, controller, motor and transmission:

• Controller efficiency: approx. 95%–98%;
• Motor efficiency: hub motors commonly 80%–88%; mid-drive with gearing can be higher;
• Transmission loss: direct-drive hub near zero; chain drive approx. 3%–8%.

Using a conservative 85% overall system efficiency: 768 × 0.85 ≈ 653Wh at the wheel.

4. Step Three: Determining Consumption (Wh/km)

This is the most critical variable, depending on total weight, speed, tyres and road conditions:

The table provides engineering experience ranges for estimation; accurate values require measurement.

5. Complete Example (Illustrative)

A 48V 20Ah leisure tricycle, total weight approx. 250kg, consumption 25Wh/km:

Range = 653Wh ÷ 25Wh/km ≈ 26km

If the customer calculates using a two-wheeler figure of 10Wh/km, they would expect 65km — and that is exactly where disputes originate.

6. Communication Advice for Overseas Customers

1. Provide three range figures in quotations: ideal conditions, normal-temperature real-world, and low-temperature;
2. State test conditions (load, speed, temperature, tyre pressure) so figures are reproducible;
3. For range-critical projects, size the battery by "daily distance × 1.3" rather than by rated range;
4. If the route includes long climbs, recalculate range with the climbing sections weighted separately.