Short circuit protection is designed to protect the battery from sudden faults that create a direct path for current flow, bypassing normal resistance.
The battery protection circuit disconnects the battery from the load when a critical condition is observed, such as short circuit, undercharge, overcharge or overheating. Additionally, the battery protection circuit manages current rushing into and out of the battery, such as during pre-charge or hotswap turn on.
Battery manufacturers provide a value of short circuit current which needs to be used for validation of proper protection device. Duration of this short circuit current can be of few seconds before a battery failure occurs. The characteristic current and duration changes depending on the battery type.
What happens if a battery does not have a short circuit?
Firstly, without external short circuit protection, the battery passes a great current for a long time leading to a rapid rise in temperature, which triggers the internal side reaction or even thermal runaway, generating a large amount of smoke, which triggers combustion under the action of electric sparks, as in the result of test 1.
Are ESC protection devices effective in external short circuits?
Two types of typical risk modes and influencing factors of ESC of battery modules are analyzed and proposed. The effectiveness and limitations of weak links for protection in external short circuits of battery modules are verified. A quantitative analysis method for the response time of the ESC protection device is proposed.
What should be considered when choosing a battery protection system?
Need to consider the case also of parallel battery strings and the case when one battery string is damaged or not available. The nominal current of the remaining battery strings in the parallel system will increase and the protection system must not trip due to this.
What is a secondary protection circuit?
Secondary protection circuits provide an additional layer of safety, activating if the primary circuits fail. This redundancy ensures the battery remains protected even under fault conditions, thereby increasing the overall safety and reliability of the battery system.