The BMS troubleshooting grades can be divided into three severity levels, corresponding to the first level of failure (minor), the second level of failure (moderate), and the third level of failure (serious), but this may be due to the different standards of each enterprise, some companies define the first level of failure as a serious failure.
The general treatment is:
- Minor fault: No safety or life impact on the battery, only alarm processing fault;
- Moderate fault: No safety or life impact on the battery, alarm, and power limit processing;
- Serious fault: No safety or life impact on the battery, do alarm and cut off processing.
Among them, the cut-off treatment of serious faults is divided into two kinds: soft cut-off and hard cut-off. Non-emergency serious faults (such as low cell voltage, high cell temperature, etc.), the normal processing logic is: sent to the controlled power devices through communication, software power down, and then the BMS software-controlled main circuit cut-off processing. Emergency serious faults (such as external short-circuit, etc.) BMS will be cut off at the hardware level, this fault processing priority is the highest. In order to ensure that the user’s experience, should be as little as possible to drive the phenomenon of power outages (vehicle breakdown), that is, as much as possible to reduce the frequency of third-level faults, based on this starting point to form a variety of fault handling measures.
MORE: How can I fix a faulty BMS or replace it with a high-quality BMS while avoiding the disassembly of all battery cells?