Electric bicycles catch fire from time to time. Shanghai Leiditech EMC has analyzed the cause, which may provide you with some insights.

The reason why electric bicycles are prone to catching fire may be due to insufficient protection function of the Battery Management System (BMS) or battery quality issues. To improve the protection function of BMS to reduce fire risk

The following points can be considered:

1) Battery quality control: Select high-quality battery suppliers and strictly control raw materials and production processes to ensure the safety and stability of batteries.

2) Over charge and over discharge protection: BMS needs to have precise over charge and over discharge protection functions to prevent the battery from overheating or even catching fire due to improper charging and discharging. More advanced voltage and temperature monitoring technologies can be considered to promptly cut off the charging and discharging circuits.

The following points can be considered:

1) Battery quality control: Select high-quality battery suppliers and strictly control raw materials and production processes to ensure the safety and stability of batteries.

2) Over charge and over discharge protection: BMS needs to have precise over charge and over discharge protection functions to prevent the battery from overheating or even catching fire due to improper charging and discharging. More advanced voltage and temperature monitoring technologies can be considered to promptly cut off the charging and discharging circuits. 3) Temperature monitoring and control: The BMS should be able to monitor the battery temperature in real-time and take protective measures when the temperature exceeds the safe range, such as stopping charging and discharging or reducing the charging and discharging rate.

4) Short circuit protection: Strengthen the monitoring and protection of short circuit situations, ensure that the circuit can be cut off in a timely manner when there is an internal short circuit in the battery, and avoid fire hazards.

5) Overload protection: BMS should be able to detect and handle battery overload situations in a timely manner, to avoid battery damage caused by long-term high load use.

Through the above improvements, the safety of electric bicycles can be improved and the risk of fire can be reduced. At the same time, users also need to pay attention to reasonable use and charging during daily use, avoiding excessive discharge and charging, to ensure the safety of electric bicycles.

Shanghai Leimao can provide various interfaces such as CAN communication and power surge protection TVS solutions in the BMS management system. It also provides application recommendations for the MOSFET control used in the BMS.

The plan is as follows:

1. Lightning protection scheme for DC 48V DC power supply

Advantages of the plan: It meets the lightning surge protection of the 48V DC power interface for outdoor equipment, meets IEC61000-4-2, level 4, contact discharge of 8KV, and air discharge of 15KV. To meet the high level surge testing requirements of IEC61000-4-5, high-power devices must be selected.

2. CAN interface lightning protection scheme

Advantages of the solution: Used for surge protection of CAN interfaces, it adopts a low residual voltage TSS, effectively protecting the interface. The TSS response time is ns level, which can prevent both surge and static electricity, and ensure signal integrity Meets IEC61000-4-2, static level 4, contact discharge 15kV, air discharge 8kV; IEC61000-4-5 surge 10/700 μ s. 8KV.

3. RS485 interface lightning protection scheme

Advantages of the solution: Adopting multiple integrated devices for protection can ensure signal integrity while filtering out noise, passing electrostatic testing. Meets IEC61000-4-2, ISO10605-2 level 4, contact discharge 30kV, air discharge 30kV, IEC61000-4-5 surge 10/700 μ s. 8KV.

If there are other lightning protection interface requirements, please contact Shanghai Leiditech EMC for consultation.