What are electric bicycle batteries?

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

E-bike batteries come in different types and with varying charging capacities. These characteristics affect which electric bikes they are compatible with and how far they can travel on a single charge. Therefore, it is worth understanding how they work so that you can choose the battery best suited to your needs.

In this article, you will learn which batteries are used in electric bikes, which key specifications they have, and which batteries are best suited to specific e-bikes.

What type of battery is used in an electric bike?

As battery technology has advanced, the performance and range of electric bikes have also improved. Early electric bike 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 These batteries were very popular in their time but have been replaced by better alternatives.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 bikes, with the global lithium-ion battery market estimated at around USD 54.6 billion. The widespread use of lithium-ion batteries is due to their numerous improvements over older lead-acid batteries. Lithium-ion batteries are not only smaller and lighter, but they also retain their charge longer, both when idle and in use.

Lead-acid batteries

The first electric bikes used lead-acid batteries, which were popular because of 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 almost 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 power tools. However, NiMH batteries have a lower charging capacity than lithium-ion batteries, so they cannot travel as far on a single charge. They also have a higher self-discharge rate, meaning they lose their charge more quickly when idle.

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

Important specifications of e-bike batteries

When buying a new electric bike, you will encounter technical terms such as voltage, amp-hours, and watt-hours. If you are unfamiliar with these terms, you risk choosing an e-bike that does not meet your needs.

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

• W: Watt describes the amount of energy an electrical device requires to perform a task. Electric bike manufacturers use two wattage ratings to identify their electric motors: continuous (nominal) power is the maximum power output over a specific period. 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 operating at a power of one watt for one hour. To calculate the Wh of an e-bike battery, multiply voltage (V) by amp-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 rating for e-bike batteries is between 36V and 52V. The higher the voltage, the more power is delivered to the electric motor.
• Amp-hours (Ah): Ah describes how many amps a battery can deliver over a specific period. For example, a 25Ah battery can deliver up to 25 amps per hour.
• Battery management system (BMS): A BMS monitors the battery and charging process, ensures that the battery supplies the correct amount of energy to the motor, and protects against overcharging and undercharging. It also ensures that the voltage is distributed evenly across all battery cells.

What battery size is best for an electric bike?

The best battery size depends on your needs and physical condition. Consider the average range you need for 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. More powerful batteries allow for longer rides on a single charge, but they are also larger and heavier. Consider whether you can manage the additional weight, as the greater mass can affect the riding experience.

Do electric bike batteries need to be replaced?

Like all e-bike components, batteries do not last forever. E-bike batteries generally have a lifespan of around 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 that the replacement battery is compatible and has the same voltage and amp-hour ratings as the original battery.

Conclusion

The battery is the heart of every electric bike. Without it, the electric assistance systems do not work. With the right battery, however, you can ride longer, sweat less, and overcome steep hills with ease.

Do you need a replacement battery or charger? Discover the full range of replacement parts in our online store.