Fire Protection Bag for Batteries & Lithium-Ion Cells | Fire Safety Bag

The fire protection bag for batteries and lithium-ion cells is an in-house development by Fingerhuth HeatProtection and is based on a fully non-combustible design that provides uncompromising safety for storing, transporting, and directly charging batteries.

The bag has been thoroughly tested at the Fraunhofer Heinrich-Hertz Institute (HHI) and certified as “suitable for this specific application.” This makes it one of the most capable solutions for handling thermally reacting lithium-ion batteries.

The multilayer construction of high-temperature-resistant silica and glass fabrics withstands continuous temperatures up to 1200 °C and short-term extreme loads up to 1600 °C. All components – including the fully metallic closure system – consist of 100% non-combustible materials. Unlike many competing products that rely on zippers, hook-and-loop fasteners, or plastic fittings that fail in a fire or may conduct flames outward, our construction remains stable even under maximum thermal load and high internal pressure.

A key advantage is the gas management system: it enables controlled release of pressure and gases and prevents escaping jet streams during a thermal runaway event. This avoids bursting and reliably protects the surrounding environment.

Another unique feature is the ability to charge batteries directly inside the bag. A laterally integrated, heat-resistant cable inlet ensures that chargers can be safely connected without compromising the fire protection function. This gives the bag a 3-in-1 functionality: storage – transport – charging in one system.

The fire protection bag has already been successfully tested with lithium-ion batteries up to 650 Wh at 100% State of Charge (SOC). Higher capacities can be realized. Moreover, the bag can be modularly scaled and customized for virtually any battery type – ideal for OEMs, service providers, research, and industrial applications.

Technical properties of the Fingerhuth fire protection bag for batteries & lithium-ion cells

The technical properties of our fire protection bag are based on a high-performance design that combines maximum safety, thermal stability, and mechanical resilience. All components are precisely engineered for use with lithium-ion batteries and ensure reliable protection even under extreme conditions such as thermal runaway, overpressure, or jet flames.

• Temperature & Fire Resistance: Permanently temperature resistant up to 1200 °C, with short-term peak loads up to 1600 °C.
• Material structure: Multi-layer construction made of silica, HR-glass and functional materials. 100% non-combustible, with no plastics, hook-and-loop fasteners or melting components. Cut- and abrasion-resistant, mechanically robust.
• Functional design: Proprietary and design developed by Fingerhuth. Offers significant advantages and enhanced safety compared to other market solutions. Purely metallic safety closure. No combustible or melting components. Withstands jet flames and overpressure.
• Gas-Management-System: Controlled pressure relief through specially arranged guiding structures. Safe discharge of gases and prevention of jet streams. Prevents bursting and ignition of pyrolysis gases by actively shielding them from oxygen.
• 3-in-1 Function (Storage – Transport – Charging): Safe use in all phases of battery handling. Ideal for workshops, industry, logistics, and private applications.
• Cable feed-through for charging: Side-mounted, heat-resistant opening for charging cables, allowing batteries to be charged inside the closed bag. Compatible with common plug types and chargers.
• Testing & Validation: Thermal runaway tests with batteries up to 650 Wh @ 100% SOC. Tested and verified by Fraunhofer HHI. Demonstrably higher protection performance compared to conventional market solutions.
• Scalability & customization: Adaptable to virtually all battery types. Custom solutions, OEM adaptations & higher Wh capacities available.

Application Examples

Thanks to its 3-in-1 functionality – storing, transporting and charging – the fire protection bag can be used in a wide range of professional and private applications. Especially in workshops, laboratories, production environments, logistics and in the daily handling of lithium-ion batteries, it offers a high level of safety and flexibility.

• Safe charging: Direct charging of lithium-ion batteries inside the bag (with cable inlet): e-bike batteries, power tool & machine batteries (Bosch, Makita, Hilti, etc.), drone, camera & model-building batteries, garden tool batteries, laboratory & test batteries.
• Storage & Transport: Safe intermediate storage in workshops, laboratories, institutes, and production environments. Fire protection during the transport of batteries in vehicles or warehouses. Securing damaged or suspicious batteries. Safe containment after accidents or malfunctions.
• Industrie & OEM: Quality control & test setups, intermediate storage of conveyor technology modules & packs, custom solutions for series production, as well as integration into service & repair processes.
• Einsatzorganisationen: Fire departments, plant security, and industrial operations; safe handling of potentially unstable batteries during emergency response.
• Privatanwendungen: Safe storage and charging of batteries in the household. Protection when charging e-bike, power tool or garden tool batteries.