The battery is the heart of any electric bicycle. Understanding common faults and how to prevent them not only extends battery lifespan but also ensures safe riding. Here are the five most common e-bike battery faults and practical prevention tips.

1. Battery Won’t Charge or Doesn’t Fully Charge

Common Causes:

• Faulty or incompatible charger

• BMS (Battery Management System) protection activated

• Deep self-discharge due to long-term inactivity

Prevention Tips:

• Use the original or compatible charger

• Charge the battery regularly and avoid long periods of inactivity

• Check the BMS regularly to ensure battery health

2. Reduced Capacity / Shortened Range

Common Causes:

• Battery approaching its cycle life limit

• Frequent deep discharge or over-discharge

• Frequent use in high or low-temperature conditions

Prevention Tips:

• Keep battery charge between 20%-80%

• Avoid prolonged exposure to extreme temperatures

• Check cell balancing regularly

3. Swollen Battery or Deformed Case

Common Causes:

• Overcharging or deep discharge

• Internal short circuit or low-quality cells

• Long-term exposure to high temperatures

Prevention Tips:

• Choose batteries with BMS protection

• Avoid charging or discharging in high-temperature environments

• Stop using immediately if swelling occurs and seek professional handling

4. Abnormal Heating

Common Causes:

• High current discharge or overload

• Increased internal resistance due to aging

• Poor connection or wiring issues

Prevention Tips:

• Avoid frequent full-load acceleration

• Check connectors and wiring regularly

• Use high-rate cells with reliable BMS

5. Battery Fails to Deliver Power / E-Bike Won’t Start

Common Causes:

• Battery charge too low

• BMS over-current or over-voltage protection triggered

• Incompatibility between battery and controller

Prevention Tips:

• Maintain reasonable battery charge levels

• Ensure battery matches the controller

• Choose batteries from reputable brands and avoid low-quality modifications

Conclusion

Regular e-bike battery maintenance, proper charging and discharging habits, and reliable BMS (Battery Management System) are key to avoiding these common faults.
For B2B buyers, evaluating cell quality, BMS protection features, and balancing function is essential to ensure battery safety, stability, and long lifespan.