What are the batteries of electric bicycles?

The battery is one of the most important parts of an electric bicycle. It supplies the electric motor with energy and enables the electric assist systems to propel the e-bike forward.

E-bike batteries come in various types and with different charging capacities. These features affect which electric bicycles they are compatible with and how far they can travel on a single charge. Therefore, it is worthwhile to understand how they work so you can choose the battery best suited to your needs.

In this article, you will learn which batteries are used in electric bicycles, what key figures they have, and which batteries are best suited for certain e-bikes.

What kind of battery is used in an electric bicycle?

With the advancement of battery technology, the performance and range of electric bicycles have also improved. Early electric bicycle models used lead-acid batteries. These batteries were very popular in their time but have been replaced by better alternatives.

Lithium-ion batteries

Lithium-ion batteries power the majority of electric bicycles, with the global market for lithium-ion batteries estimated at around 54.6 billion USD. The widespread use of lithium-ion batteries is due to numerous improvements compared to older lead-acid batteries. Lithium-ion batteries are not only smaller and lighter but also hold their charge longer, both when idle and in use.

Lead-acid batteries

The first electric bicycles used lead-acid batteries, which were popular due to their low production costs and easy recyclability. However, lead-acid batteries have lost popularity because of their large size, heavy weight, and limited range. In fact, they last only half as long as lithium-ion batteries and weigh nearly three times as much.

Nickel-metal hydride (NiMH) batteries

NiMH batteries are a better alternative to lead-acid batteries. They are more environmentally friendly and more resistant to cold weather, which is why they are often used in portable electric tools. However, NiMH batteries have a lower charging capacity than lithium-ion batteries, so they cannot travel as far on a single charge. Additionally, they have a higher self-discharge rate, meaning they lose their charge faster when idle.

READ MORE: What is an electric bicycle and how does it work?

Important key figures of e-bike batteries

When buying a new electric bicycle, you will come across technical terms such as voltage, ampere-hours, and watt-hours. If you do not know these terms, you risk choosing an e-bike that does not meet your needs.

Here is an overview of the most important key figures of e-bike batteries:

• Watt (W): Watt describes the amount of energy an electrical device needs to perform a task. Electric bicycle manufacturers use two watt values to label their electric motors: The continuous (nominal) power is the maximum power output over a certain period. The peak power is the maximum power output during a short burst.
• Watt-hours (Wh): Wh describes the amount of work an electrical device performs when it runs for one hour at a power of one watt. To calculate the Wh of an e-bike battery, multiply voltage (V) by ampere-hours (Ah). Example: 36V x 7Ah = 252 Wh.
• Voltage (V): Voltage determines the strength of the current flowing from the battery to the electric motor. The average voltage value for e-bike batteries is between 36V and 52V. The higher the voltage, the more power is delivered to the electric motor.
• Ampere-hours (Ah): Ah describes how many amperes a battery can deliver over a certain period. For example, a 25Ah battery can deliver up to 25 amperes per hour.
• Battery management system (BMS): A BMS monitors the battery and the charging process, ensures the battery delivers the right amount of energy to the motor, and protects against overcharging and deep discharge. It also ensures that the voltage is evenly distributed across all battery cells.

What battery size is best for an electric bicycle?

The best battery size depends on your needs and physical condition. Consider the average range you need on your rides. If you only travel short distances in the city, a battery with 5 to 10 Ah is sufficient. For longer rides, you should choose a battery with 10 to 20 Ah.

Another factor is your physical condition. Stronger batteries allow longer rides on a single charge but are also larger and heavier. Consider whether you can handle the extra weight, as the greater mass can affect the riding experience.

Do electric bicycle batteries need to be replaced?

Like all e-bike components, batteries do not last forever. Typically, e-bike batteries have a lifespan of about two to five years (10,000 to 30,000 kilometers). After this time, the battery’s capacity begins to decline.

If your battery needs to be replaced, make sure the replacement battery is compatible and has the same voltage and ampere-hour values as the original battery.

Conclusion

The battery is the heart of every electric bicycle. Without it, the electric assist systems do not work. However, with the right battery, you can ride longer, sweat less, and easily overcome steep hills.

Need a replacement battery or charger? Discover the full range of spare parts in our online shop.