Capacity (Energy Storage) | From 5 kWh up to MWh-scale is 20 MWh, 40 MWh, 100 MWh+… | Indicates how much stored energy is available for use. Determines duration of backup or continuous supply. |
Power Rating | Sizes from kW to MW ratings is 50 kW, 500 kW, 1 MW+… | Determines how much load the system can support at any moment (how fast it can discharge). |
Power-to-Energy Ratio (C-rate) | Varies is 0.5C, 1C, 2C+… | Determines how quickly the battery can be charged/discharged. High C-rate = faster response. |
Depth of Discharge (DoD) | Typically 80-95 % for Li-ion; lower for other chemistries | Higher DoD lets you use more of the battery energy without harming lifetime. |
Round-Trip Efficiency | ~85-95 % | What fraction of input energy is available for use after losses. |
Cycle Life | 4,000-10,000 cycles (if large Li-ion / LFP); longer for flow battery etc. | Determines how long the BESS will perform before capacity degrades significantly. |
Calendar Life | Typically 10-20 years | Ageing over time even if the battery is not heavily cycled. |
Operating Temperature Range | −20 °C to +50 °C (depending on system); with thermal management | Ensures performance and safety in different climates. |
Safety & Certifications | UL 9540 / UL9540A, IEC 62619, IEC 61427, NFPA / local codes etc. | Ensures system meets national/international safety, fire, environmental, and electrical standards. |
Monitoring & Management | Integrated Battery Management System (BMS), Energy Management System (EMS), remote monitoring | For live analytics, cell balancing, safety, optimised operation. |
Power Conversion | Bi-directional PCS/inverter; AC / DC coupling depending on use case | To convert between battery’s DC and the AC load/grid; allows flexible system configurations. |
Modularity & Scalability | Modular battery / cabinet units; containerised systems for large scale | Makes installation easier; allows scaling up as demand grows. |
Maintenance & Warranty | ≥5-10 years warranty typical; warranty on capacity retention (e.g. ≥80 % after X years/cycles) | Important for reliability and lifetime cost of ownership. |