The electric bicycle, or e-bike, has transformed the way we think about cycling. At its core, an e-bike is essentially a traditional bicycle enhanced with a pedal-assist electric motor. Pedal as you normally would, and the motor kicks in automatically, providing a helpful boost when needed—such as while climbing hills. The experience feels more powerful than a regular bike, but otherwise seamless.

Some models feature a throttle option, which allows riders to activate additional power with a simple button press. This extra mode can be especially beneficial on race tracks or for those seeking an even more robust riding experience. E-bikes are becoming increasingly popular as eco-friendly alternatives to driving. They’re efficient for short commutes and promote physical activity. If you're thinking about purchasing an e-bike, understanding its technical specifications is essential.

The electric motor is the heart of any e-bike, and most models operate using similar technologies. These motors are typically characterized by several key parameters, including wattage and battery capacity. The battery itself is described using specific electrical metrics as well. But what exactly do these terms mean? And how do you choose the right specifications for your needs? This article breaks down the basics so you can make informed decisions when selecting an e-bike.

What Are Watts?

The Watt (W) is the standard unit of electric power. It applies not only to electric motors but also to other forms of energy, like human effort. For e-bike motors, a higher wattage generally means greater power and performance. Most e-bike motors range between 250-300 watts, but this number alone doesn't provide much insight into actual performance. Two important wattage ratings are typically used to describe e-bikes:

• Continuous watt rating: This indicates the motor's nominal power under normal operating conditions.
• Peak watt rating: This reflects the maximum power output achievable under demanding circumstances, such as steep inclines. This value may be several times higher than the continuous rating provided by manufacturers.

Electric power (measured in watts) equals voltage multiplied by current. Why is wattage significant for e-bikes? It gives you an idea of the bike's overall power capabilities. Opt for a higher wattage if you anticipate using your e-bike on challenging terrains or hilly routes.

When evaluating battery capacity, another metric comes into play: the Watt Hour (Wh). A higher Wh rating signifies a larger battery capacity. This figure tells you how long the battery can sustain the motor before needing a recharge. When shopping for an e-bike, the Wh rating helps you compare various battery options.

For example, a 500 Wh battery can power a 250 W motor for approximately two hours. Conversely, if the motor requires 500 W, the battery will last only one hour. Therefore, when choosing an e-bike with a more powerful motor, prioritize the Wh rating of the accompanying battery—especially if you plan long-distance trips without frequent charging stops.

What Are Volts?

Voltage, also known as electric potential, is expressed in Volts (V). In a battery, the number of volts represents the “pressure” exerted by the battery to push electrons through wires. E-bike motors consist of copper coils, so a higher voltage results in a stronger flow of electrons through the motor's coils.

This increased electron flow directly correlates with faster assisted speeds and improved hill-climbing abilities. The movement of electrons through a conductor is termed electric current and is measured in Amperes (Amps). To simplify the concept, voltage is often likened to water pressure in a pipe, where current corresponds to the rate of water flow.

While e-bikes come in varying voltages, the most common are 36 V and 48 V. With this knowledge, let’s perform some basic calculations. An e-bike running on 36 V with a 10 Amp draw has a power output of 360 W, which aligns with many modern e-bikes. Comparing this to a 500 W motor provides perspective on its strength.

There’s something intriguing worth noting here. From these computations, we see that higher voltages can achieve greater power outputs using less current. High currents often lead to overheating in wires and electronic components. Returning to our water analogy, a large flow necessitates a wider pipe. Similarly, allowing for higher currents requires thicker wires and bulkier electronics. Modern e-bikes favor higher voltages because they enable slimmer wiring and more compact electronics.

Thus, when comparing different e-bikes, aim for higher voltages whenever feasible. Keep in mind, though, that no single parameter offers the complete picture; you must consider all factors collectively.

What Are Amp Hours?

For batteries, you won’t find a current value used for characterization. Instead, the Amp Hours (Ah) rating is far more prevalent. Like Wh, Ah measures battery capacity. Essentially, a 10 Ah battery can supply 10 Amps of current for one hour or 1 Amp for ten hours. To accurately compare batteries based on Ah, ensure they share the same voltage level.

Practically speaking, Ah isn’t as effective for comparing batteries across different e-bikes unless voltage is taken into account. Consequently, Wh is usually preferred. You can calculate Wh from Ah and voltage by multiplying the two values.

For instance, a 36 V battery rated at 10 Ah holds 360 Wh of capacity. As explained earlier, Wh provides a clearer understanding of an e-bike’s battery and motor performance.

Delfast Sets the Standard with Wh Batteries

Delfast surpasses expectations in this industry. Their electric bikes are fitted with a 20S15P Panasonic battery delivering 72 V and boasting a 48 Ah rating, equivalent to 3456 Wh. Thanks to its high voltage, the accompanying electronics and wiring are notably compact. This type of battery supports up to 3000 charge cycles. By contrast, typical e-bikes on the market endure roughly 1000 charge cycles at most.

Conclusion

You now possess a solid grasp of the key electrical parameters to consider when purchasing an e-bike. To summarize, wattage determines motor power, ensuring the battery’s Wh rating matches your desired riding duration without recharging. Voltage plays a crucial role too; higher voltages are preferable.