Nominal DC system voltage. Standard values: 24, 48, 125, or 250 VDC. 125 VDC is most common for substation control power per IEEE 485. If omitted, defaults to 125 VDC.

Total continuous DC load current in amperes. Sum of all loads that run for the full autonomy period (relays, RTUs, lighting, inverters). Typical: 10-60A for distribution substations, 50-200A for transmission substations, 200-600A for datacenter DC systems.

Peak momentary load current in amperes. Includes breaker trip coils, motor-operated switches, and other short-duration loads that occur during the duty cycle. Typical: 50-300A for breaker trip coils, 0 if no momentary loads. If omitted, defaults to 0 A.

Duration of the momentary load in minutes. Per IEEE 485, typically 1 minute for breaker operations. Used to convert momentary load to amp-hours. Typical: 1 min per IEEE 485. Rarely exceeds 5 min. If omitted, defaults to 1 minute.

Required backup duration without charging in hours. IEEE 485 typical: 4-8 hours for substations, 0.25-2 hours for UPS applications. If omitted, defaults to 8 hours.

Battery chemistry. VRLA (valve-regulated lead-acid) is maintenance-free, common in datacenters. LEAD_ACID_VENTED (flooded) offers longer life (20+ yr) for substations. NICKEL_CADMIUM for extreme temperatures (-40 to 50 C). If omitted, defaults to VRLA.

Expected ambient temperature at the battery location in degrees Celsius. Capacity derates below 25 C and life degrades above 25 C. IEEE 485 reference is 25 C. Typical: 20-25 C for conditioned rooms, 30-40 C for outdoor/unconditioned. If omitted, defaults to 25 C.

Minimum allowable cell voltage at end of discharge in volts. Overrides the default end voltage per cell (e.g. 1.75 V/cell for lead-acid). Lower values extract more capacity but shorten cell life. If omitted, uses the standard end voltage per cell for the selected battery type.