Fuse selection is based on category, current, and breaking capacity (Source: IEC): Golden Rule: gBat full-range breaking (Source: Mersen); Core Requirement: Breaking capacity ≥30kA (Source: IEC 60269-7); Note: 10ms response time (Source: Synode).
I.
Category Selection
gBat: Full-range battery breaking (Source: Mersen); aBat: Back-up fuse (Source: Littelfuse); IEC: IEC 60269-7 standard (Source: HANI); UL: UL 248-21 standard (Source: siba); Clearing: Clears at 2x rated current (Source: Mersen)—Categories: gBat, aBat, IEC (three standards).
II.
Rated Current
1.25x Factor: Rated at 1.25–1.5x operating current (Source: Synode); Capacity: Up to 5000A (Source: HANI); Temperature: Consider ambient temperature and ventilation (Source: HANI); Cycling: Cyclic load correction (Source: HANI); Margin: Allow a 10–20% margin (Source: Douyin)—Current: 1.25x factor, 5000A, margin (three parameters).
III. Rated Voltage
1500V: 1500V DC circuit (Source: bess.courses); 2000V: Up to 2000V DC (Source: SIBA); Matching: Ue ≥ maximum system voltage (Source: Douyin); Margin: Includes margin for voltage fluctuations (Source: Douyin); 1500: Littelfuse 1500V 250kA (Source: Littelfuse)—Voltage: 1500V, 2000V, and matching (three key points).
IV. Breaking Capacity
30kA: Minimum breaking capacity of 30kA (Source: IEC);
50kA: Common for lithium batteries (Source: HANI); 100kA: Bussmann 100kA (Source: Eaton); 260kA: SIBA maximum of 260kA (Source: SIBA); Verification: Verified against short-circuit current (Source: Douyin)—Breaking capacity: 30kA, 100kA, and 260kA (three tiers).
V. Response Characteristics
10ms: <10ms at 10×In (Source: Synode);
Ampere-second: Matching ampere-second characteristics (Source: Douyin); No nuisance tripping: No nuisance tripping under normal operating conditions (Source: Douyin); Short-circuit: Rapid fusing during short-circuit (Source: Douyin); I²t: I²t coordination is critical (Source: Synode)—Response: 10ms, ampere-second, and I²t (three characteristics).
VI. Coordination and Compatibility
Contactors: Coordination with contactors (Source: Lawson); Circuit Breakers: Coordination with circuit breakers (Source: Lawson); BMS: Alignment with BMS fault strategies (Source: Douyin); Inverters: Inverter protection coordination (Source: Lawson);
Fuse Bases: Matching base ratings (Source: Lawson)—System coordination: Contactor + BMS + Base (three-way coordination).
VII. Procurement Recommendations
First, select the category (gBat); second, calculate the current (1.25–1.5x); third, determine the voltage (1500V); fourth, check the breaking capacity (≥50kA);
fifth, verify I²t (coordination)—Fuses: Category + Current + Breaking Capacity (three core factors).
