What size battery energy storage container do I Need?

From small 20ft units powering factories and EV charging stations, to large 40ft containers stabilizing microgrids or utility loads, the right battery energy storage container size can make a big difference.

How do I choose a containerized energy storage system?

Choosing between these sizes depends on project needs, available space, and future scalability. Regardless of format, each containerized energy storage system includes key components such as battery racks, BMS, EMS, cooling, and fire protection.

What factors should you consider when choosing a 40ft container?

Consider these practical factors: Site footprint and installation space: A 40ft container may offer more capacity, but only if the site can accommodate it. Power and energy requirements: Some applications need high discharge power (kW), while others prioritize total energy (kWh).

How important is a battery energy storage container?

Container size alone doesn’t determine a BESS system’s effectiveness — design and layout also matter. A well-structured battery energy storage container optimizes internal airflow, reduces cable loss, and ensures better thermal control.

How much energy can a ESS unit store?

Individual ESS units shall have a maximum stored energy of 20 kWh per NFPA Section 15.7. NFPA 855 clearly tells us each unit can be up to 20 kWh, but how much overall storage can you put in your installation? That depends on where you put it and is defined in Section 15.7.1 of NFPA 855.

Why is container size important?

For commercial and industrial users, this is especially important — over-sized systems waste money and space, while under-sized systems can’t meet energy demands. Beyond space, the physical container dimensions affect transportation, cooling design, fire safety, and how easily the system can scale over time.