Safety cabinets for fire-resistant storage of lithium-ion batteries explained

EN 14470-1 cabinets are designed to protect contents from an external fire. Battery cabinets, in contrast, must contain an internal fire and prevent its spread. They are built to resist flames from inside out, relieve pressure, filter toxic gases and allow connection to an exhaust system.

The German association VDMA has introduced specification VDMA 24994, now considered the benchmark. Though not yet a European standard, it is widely accepted by manufacturers, insurers and safety authorities.

Tested aspects

1. Internal fire (thermal runaway) – Prevent flames and heat from escaping.
2. External fire – 30, 60 or 90 min resistance depending on class.
3. Smoke and toxic gases – Cabinet must stay sealed, equipped with sensors and exhaust connection (≥ 30 m³/h).
4. Fire spread prevention – Fire at one storage level must not ignite others.
5. Explosion resistance – Withstand pressure waves without door failure.
6. Projectile protection – Contain all fragments during an explosion.

Classes

• Class I – protection against internal risks only.
• Class I/O30 – internal protection + 30 min external fire.
• Class I/O60 – internal protection + 60 min external fire.
• Class I/O90 – internal protection + 90 min external fire.

• Doors must close automatically within 1 minute, or alarm if left open.
• Charging must stop automatically when the door is opened.

Certification

A cabinet is only officially compliant with VDMA 24994:2024-08 if certified by ECB·S, including initial plant audits and annual unannounced inspections.

Ventilation

A fixed exhaust is not mandatory, but cabinets must be prepared for connection. Without extraction, a risk assessment is required.

Conclusion

There is no such thing as zero risk, but cabinets certified to VDMA 24994 effectively minimise the dangers of internal battery fires, toxic gases, explosions and projectiles. They are the most reliable choice for storing and charging lithium-ion batteries safely.