In short, the following factors should be considered when selecting a fuse for a given system:Normal operating currentOperating VoltageAmbient TemperatureInrush CurrentsMaximum Fault CurrentLength of time in which the fuse must openMaximum allowable I2t.
Battery fuses are designed to protect Lithium-ion (Li-ion) batteries from potentially damaging and dangerous overcurrent and overcharging events. The devices safeguard components, equipment, and people from risk of fire and electric shock. Overcurrent protection can be achieved by using current fuses or battery fuses.
The fuses in a battery pack protect the battery and the other electrical components against high currents. There are special off-the-shelf components similar to 12V starter battery fuses. However, EV fuses are rated for high voltage and traction currents. The page has a list of EV fuse manufacturers.
For quality assurance, some reliable and safe brands to consider are Blue Sea Systems and Little Fuse. In large battery banks, the fuse selection becomes even more critical. UL 248-14 certification fuses are advisable. Smaller style fuses mentioned earlier like the 10x38 fuses, may not suffice.
How do I know if my EV battery fuses are good?
Check the contactor-fuse coordination for normal operation, overloads and failure currents. The fuses in a battery pack protect the battery and the other electrical components against high currents. There are special off-the-shelf components similar to 12V starter battery fuses. However, EV fuses are rated for high voltage and traction currents.
The fuse selection procedure is very similar to contactor selection and complementary parameters help to select EV fuses. Fuse datasheets include breaking current-time characteristics. Some of the fuse manufacturers also provide thermal and mechanical characteristics. Fuses are simple busbars with melting elements inside.
How a battery fuses protect against overcurrent?
Overcurrent protection can be achieved by using current fuses or battery fuses. Current fuses protect against overcurrent. On the other hand, a battery fuse is used in a Battery Management System (BMS) as a secondary protection element. In case overcurrent occurs while using the device, the fuse element will open and cut off the circuit.