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batrea · lithium-ion battery storage cabinet

Store and charge lithium-ion batteries safely.

batrea is a fire-resistant storage cabinet for storing and charging lithium-ion batteries. Tested and certified to VDMA standard sheet 24994:2024-08 in classes I/O30 and I/O60. Offered through the specialist trade, with contacts at Müller Safe in Herborn, Germany.

Certified to VDMA 24994:2024-08 I/O30I/O60
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batrea 3 lithium-ion battery storage cabinet, closed, RAL 7035 body with black control panel top and exhaust air connection
01–07 Seven chapters

What is a lithium-ion battery storage cabinet, and when do you need one?

A lithium-ion battery storage cabinet is a closed, fire-resistant enclosure in which batteries are stored and charged so that a thermal runaway stays contained, is detected early and its gases are extracted in a controlled way. The benchmark for such cabinets is VDMA standard sheet 24994:2024-08. batrea is certified to it in classes I/O30 and I/O60, allows charging inside the cabinet and holds up to 3000 Wh per storage level. Also called battery charging cabinet or fire-resistant battery cabinet.

  1. 1 Risk
  2. 2 Typical situations
  3. 3 Solution
  4. 4 Cabinet design
  5. 5 Safety features
  6. 6 Sizes and classes
  7. 7 Advice and enquiry

Last updated:

On record

Standard sheet VDMA 24994:2024-08 Test requirements for fire-resistant storage cabinets for lithium-ion batteries in the event of a thermal runaway
Classes I/O30 · I/O60 I: internal fire test passed · O: external fire test over 30 or 60 minutes (meaning per standard sheet, see chapter 3)
Certification ECB•S Certification is issued by an independent certification body and tested at ECB•S-recognised partner laboratories (data sheet).
Test cells NMC 9-0.5-0.5 Tested with NMC 9-0.5-0.5 cells, described by the manufacturer as the most hazardous battery type (data sheet)
Construction EN 1143-1 Body and door construction based on resistance grade I according to EN 1143-1
Capacity 3000 Wh per storage level, maximum charging power 3000 W per level, 100 kg per shelf

Certificates 2201/LIB25-02 (I/O60, size 1) and 2201/LIB25-03 (I/O30, sizes 1 to 3), issued by European Certification Body GmbH (ECB•S), valid until 7 April 2029.

What happens during a thermal runaway

A thermal runaway is a self-accelerating reaction inside a lithium-ion cell: above a critical temperature the separator, electrolyte and electrode materials decompose, the cell keeps heating itself, releases flammable and toxic gases and can drag neighbouring cells into the same reaction.

What sets it apart from an ordinary fire is that the energy sits inside the cell. Cutting off oxygen therefore helps only to a limited degree, and a cell that appears extinguished can reignite. The German accident insurers describe triggers, course and firefighting strategy in DGUV Information 205-041 (March 2024); the five states below summarise it.

What happens during a thermal runaway 01 Trigger · 02 Heating · 03 Gas release · 04 Ignition · 05 Propagation 01 02 03 04 05
  1. 01

    Trigger

    Overheating, overcharging or an internal short circuit. Prior damage from impact, dropping, heat, frost or direct sunlight raises the risk.

    Source: DGUV Information 205-041, 2024

  2. 02

    Heating

    The cell heats faster than it can shed heat. Nothing is visible from outside at first; a temperature rise in the storage area is the first measurable signal.

    Source: DGUV Information 205-041, 2024

  3. 03

    Gas release

    When the pressure relief opens, a white-grey, flammable mist of electrolyte and cell components escapes. The gases and dusts released are partly highly toxic or carcinogenic.

    Source: DGUV Information 205-041, 2024

  4. 04

    Ignition

    The gas mixture ignites. A battery fire rarely occurs without explosive combustion and without the release of ignitable gases.

    Source: GIT Sicherheit, interview on VDMA standard sheet 24994, 2025

  5. 05

    Propagation

    The reaction jumps to neighbouring cells and batteries (thermal propagation). Every protective measure therefore aims to confine the event to the affected battery and to cool it for a long time.

    Source: DGUV Information 205-041, section 6.3, 2024

What this means for a business

The fire itself is not the whole risk; its consequences are: smoke in the building, spread to stored goods, business interruption and the question whether the property insurer accepts the storage arrangement as proper. A tested storage cabinet answers exactly these questions. It does not answer the question of battery quality.

All statements in this chapter are guidance drawn from public sources. The current versions of the respective regulations apply.

Where the risk arises in everyday work

Lithium-ion batteries are rarely the core business of a company. They accumulate: in tool cases, on chargers, in return crates, in vehicles. The situations below are typical starting points of an enquiry. For resellers they double as a map of the target groups.

Scroll sideways or use the arrows

  • 01 Power tool batteries

    Workbench and charging corner

    Trades, workshops, maintenance

    Power tool batteries charge on the bench or on shelves next to combustible material. Charging is the critical state because energy is being fed in.

  • 02 E-bike batteries

    Bicycle retail and workshop

    E-bikes, pedelecs, cargo bikes

    Customer batteries with several hundred watt-hours are charged, stored and accepted for repair, often in the sales area.

  • 03 Unknown condition

    Returns and damaged batteries

    Retail, service, repair

    Returned or damaged batteries of unknown condition wait for inspection or disposal. Swollen or damaged batteries must not be charged.

  • 04 Swap batteries

    Cleaning machines and industrial trucks

    Facility services, intralogistics

    Swappable batteries for scrubber-dryers, pallet trucks and order pickers are recharged continuously in shift operation.

  • 05 Many users

    Laboratories, schools, universities

    Education, research

    Measuring instruments, prototypes and collections of small batteries in rooms with many people and changing use.

  • 06 Transport preparation

    Logistics and dispatch preparation

    Warehouse, shipping, dangerous goods

    Batteries are collected, packed and prepared for transport; storage and charging belong in separate places.

  • 07 Standby

    Municipal services and emergency teams

    Depots, fire brigades, ambulance services

    Battery-powered equipment on permanent standby, frequently in vehicle halls alongside other kit.

  • 08 Permanent charging

    Medical and measurement technology

    Practices, hospitals, test labs

    Device batteries that must be available at all times and therefore stay on the charger permanently.

Typical triggers of an enquiry

  • Inspection by the accident insurer or the fire service
  • Requirement from the property insurer
  • Risk assessment under hazardous substances law
  • Incident on the premises or nearby
  • New building, change of use or tender
  • Growing battery stock without a fixed storage place

Separate, contain, detect, extract

A lithium-ion battery storage cabinet is a closed enclosure that separates batteries from their surroundings during storage and charging, contains an event inside, detects temperature and smoke and extracts gases in a controlled way. What such a cabinet has to withstand is defined by VDMA standard sheet 24994:2024-08.

  1. 01

    Separate

    The batteries sit in a multi-walled, locked enclosure, not on the workbench.

  2. 02

    Contain

    Body, door, bolt work and seal keep flames, pressure and smoke inside.

  3. 03

    Detect

    Sensors report a temperature rise and smoke before anyone outside notices.

  4. 04

    Extract

    An exhaust air connection removes gases; in an emergency the flap closes automatically.

Why a steel cabinet is not enough

An ordinary steel cabinet, or a hazardous materials cabinet to EN 14470-1, is designed for fire from outside: it protects the contents from a room fire for a defined time. A thermal runaway takes place inside, with pressure, gas and heat. The European Security Systems Association (ESSA) points out that EN 14470-1 is not comparable with VDMA 24994 because it does not test the explosion risk inside the cabinet (Protector, May 2025).

What VDMA 24994:2024-08 tests

VDMA 24994:2024-08 is a standard sheet of the German Mechanical Engineering Industry Association (VDMA) setting out test requirements for fire-resistant storage cabinets for lithium-ion batteries in the event of a thermal runaway. Published in August 2024, it applies to removable, portable batteries of up to 25 kg that may also be charged inside the cabinet.

  • The internal fire test ("I" for inside) triggers a thermal runaway in a battery box inside the cabinet. It is not defined in minutes but by the stored energy in watt-hours: the cabinet has to withstand the entire energy potential inside.
  • The external fire test ("O" for outside) is optional and checks how long the batteries are protected from a room fire: 30, 60 or 90 minutes, in a procedure similar to EN 14470-1.
  • Testing uses NMC cells as a highly reactive cell chemistry, loaded to the worst case on one shelf.
  • The standard sheet does not test battery properties or active extinguishing or fire alarm systems inside the cabinet, and it sets no minimum construction requirements.

Sources: FeuerTRUTZ (July 2024), GIT Sicherheit (2025), Protector/ESSA (May 2025). Reproduced as guidance; the standard sheet itself is available from the VDMA and DIN Media.

What I/O30 and I/O60 mean

The certification scheme knows four classes: I, I/O30, I/O60 and I/O90. "I" stands for the internal fire test passed; the number after "O" is the duration of the additional external fire test in minutes. batrea is certified in classes I/O30 and I/O60. Which class suits a location depends on the fire load of the surroundings and on the requirements of insurer and risk assessment; we advise on this. The documents available to us do not describe a technical difference in the construction of the two batrea classes.

What the cabinet expressly does not do

  • It does not replace a risk assessment under hazardous substances law.
  • It does not replace a fire alarm system or an extinguishing system.
  • It does not replace ventilation planning: the connection to a suitable ventilation system has to be provided on site.
  • It does not judge the condition of a battery: swollen, leaking or damaged batteries must not be stored or charged.

Regulations for orientation Guidance only, not a product property

These German regulations address the operator, not the cabinet. They help resellers in advising customers; the current original text is binding. Requirements in other countries differ.

  • VDMA 24994:2024-08Test requirements for storage cabinets; basis of the batrea certification.August 2024
  • DGUV Information 205-041Fire protection when handling lithium-ion batteries: triggers, storage, charging, firefighting.March 2024
  • VdS 3103Property insurers' guideline: power classes (batteries above 100 Wh count as "medium power"), separated storage areas or clearances.VdS Schadenverhütung
  • TRGS 510Storage in portable containers: risk assessment, separation of storage and charging; lithium batteries are treated like flammable solids in practice.Edition 2021

How batrea is built

batrea comes from safe manufacturing: body and door are multi-walled, the door locks on four sides through bolt work, and an expansion and smoke seal closes the gap. The section drawing shows what the data sheet describes and nothing beyond it.

Section drawing of batrea: wall structure, door leaf, bolt work, seal, exhaust air path Schematic section through the storage cabinet. From outside in: multi-walled body with insulation combination, multi-walled door leaf with four-sided locking and expansion and smoke seal, inside one storage level with batteries, on top the DN100 exhaust air connection with ventilation flap and the control panel. 01 Multi-walled body 02 Multi-walled door leaf 03 Four-sided locking 04 Expansion and smoke seal DN100 · 30 m³/h 05 Exhaust air path DN100 06 Control panel top
  1. 01

    Multi-walled body

    Multi-walled construction of the cabinet, body and door with a special combination of insulating materials. The inner wall holds the event; the insulation limits heat transfer to the outside.

  2. 02

    Multi-walled door leaf

    A single multi-walled door leaf closes the front. Body and door construction are based on resistance grade I according to EN 1143-1.

  3. 03

    Four-sided locking

    The door locks on four sides, all round via bolt work. In an event it stays shut instead of being forced open by pressure.

  4. 04

    Expansion and smoke seal

    A special expansion and smoke seal in the door rebate closes the gap between door and body against smoke.

  5. 05

    Exhaust air path DN100

    The DN100 galvanised steel ventilation connection links the cabinet to the on-site exhaust system; minimum air flow 30 m³ per hour. In an emergency the ventilation flap closes automatically, and its position is indicated.

  6. 06

    Control panel top

    The control panel top in RAL 9005 sits on the body and carries the diagnostic control panel, the fuse box and the emergency stop button. The body is finished in RAL 7035; handle and key escutcheon are black.

  7. 07

    Lock and anchoring

    Key lock class A with two 120 mm keys, or electronic lock class A. Two through-holes in the base for optional anchoring at the installation site.

Footprint, weight, delivery, connections

A batrea weighs between 294 and 630 kg. That is a selling point and a planning task at the same time. Resellers do well to settle these points before quoting.

Footprint
Overall depth 762 mm including handle, overall width 711 or 733 mm including the ventilation spigot. Allow for door swing and opening radius.
Weight and floor
294, 450 or 630 kg on roughly 0.5 m² of floor area. Check floor load capacity and the transport route (door widths, lift, floor level) in advance.
Delivery
Delivered by freight forwarder; positioned with lifting equipment. Transport to upper floors, anchoring and alignment are agreed per site. Müller Safe's transport and anchoring questionnaire collects the required details (German).
Anchoring
Two through-holes in the base. Under Müller Safe's terms, commissioned anchoring uses a maximum of two drill holes per cabinet, and an anchoring form is then mandatory.
Exhaust air
DN100 connection, minimum air flow 30 m³/h, on-site ventilation system required. The cabinet must be connected to a suitable ventilation system (manufacturer's quick guide).
Power
Mains connection 230 V/50 Hz via an earthed socket; factory-fitted power cable 4.5 m; circuit protection according to the technical specification (manufacturer's quick guide).
Size comparison batrea 1, 2 and 3 to scale Three silhouettes to scale with overall heights 754, 1269 and 1969 mm, overall width 711 or 733 mm; reference line at 1000 mm. Reference 1 m 754 mm batrea 1 711 × 762 mm · 294 kg 1,269 mm batrea 2 733 × 762 mm · 450 kg 1,969 mm batrea 3 733 × 762 mm · 630 kg
Three silhouettes to scale with overall heights 754, 1269 and 1969 mm, overall width 711 or 733 mm; reference line at 1000 mm.

Who stands behind the offer

Müller Safe GmbH in Herborn, Germany, manufactures safes and security containers in its own plant (laser cutting, bending, welding, powder coating) and is a member of the VDMA security systems association and of the European Security Systems Association (ESSA). Müller Safe looks after batrea in the German market: advice, quotation, delivery, after-sales.

Manufacturing
TRUMPF TruLaser 3030 · Gasparini PBS 135 · MIG/MAG/SAW welding · Wagner powder coating
Associations
VDMA security systems association · ESSA
After-sales
Lock fitting and programming · spare keys · maintenance · transport · emergency opening · repair · disposal

The diagnostic control panel

The control panel top carries LED indicators, piezoelectric buttons, the emergency stop and the fuse box. The assignment of the ten elements comes from the manufacturer's quick guide (V 1.0). Tap or click a marker.

batrea control panel with ten labelled elements From left to right: UNLOCKED, SMOKE, OK, START, STOP, TEST, ALARM, 50 °C, 60 °C, then the batrea mark; at the right edge of the top the emergency stop button. UNLOCKED SMOKE OK START STOP TEST ALARM 50 °C 60 °C Emergency stop batrea
  1. 1 UNLOCKED Indicator: door unlocked or open. With the door open the system neither starts nor continues charging.
  2. 2 SMOKE Indicator: smoke detected inside the cabinet. Part of the critical alarm (stage 2) with continuous tone.
  3. 3 OK Normal operation. The cabinet is working and the sockets are powered.
  4. 4 START Start button: starts charging and switches the sockets on. Requires the door to be closed and locked.
  5. 5 STOP Stop button: ends charging and switches the sockets off.
  6. 6 TEST System test: runs automatically for about three seconds, alarm indicators light up and an acoustic signal sounds. Checks the main safety systems.
  7. 7 ALARM Critical alarm (stage 2): smoke or critical temperature detected, continuous tone. Do not open the door, keep your distance, call the emergency number if you see smoke or fire.
  8. 8 50 °C Warning (stage 1): raised temperature inside the cabinet, intermittent acoustic signal. Watch the cabinet closely.
  9. 9 60 °C Critical temperature reached. The automatic ventilation shutdown responds to the detection of a high temperature (60 °C); the ventilation flap closes.
  10. 10 Emergency stop Emergency shutdown (STOP/EMERGENCY). Use only in case of immediate danger to life or health.
From left to right: UNLOCKED, SMOKE, OK, START, STOP, TEST, ALARM, 50 °C, 60 °C, then the batrea mark; at the right edge of the top the emergency stop button.

Active safety functions

  1. 01

    Detect temperature rise

    The intuitive diagnostic control panel with piezoelectric buttons reports a temperature rise inside the cabinet: warning at raised temperature, critical alarm at critical temperature.

  2. 02

    Detect smoke

    Smoke detection inside the cabinet. Smoke is among the first signs of a developing event and triggers the critical alarm.

  3. 03

    Shut down ventilation automatically

    Automatic ventilation shutdown when a high temperature (60 °C) is detected. The ventilation flap closes automatically in an emergency; its position is indicated.

  4. 04

    Charge only with the door closed

    With the door open the system neither starts nor continues charging. Doors must stay closed during storage and charging.

  5. 05

    Emergency stop and fuse set

    Emergency shutdown (STOP/EMERGENCY), buzzer for acoustic signals and a fuse set with two fuses in the fuse box above the control panel.

Limits per storage level

  • 3000Whmaximum energy of the stored batteries on one storage level
  • 3000Wmaximum charging power on one storage level
  • 100kgmaximum load per shelf

What to do in case of an alarm

The manufacturer's quick guide is unambiguous: during a critical alarm do not open the cabinet door, because the cabinet is designed to contain a possible fire inside. Assess the situation from a safe distance; if you see smoke or fire, call the emergency number and state that a lithium-ion battery cabinet is involved, warn others and evacuate. If the alarm persists without visible signs, inform the person responsible and do not resume operation on your own.

Source: Quick guide batrea storage cabinet, V 1.0, section 6 (manufacturer document)

Three sizes, two classes, three socket types

The size determines storage levels, sockets, capacity and weight. All values come from the data sheet and apply equally to both classes.

batrea 1

batrea 1 lithium-ion battery storage cabinet with one storage level, open
Storage levels
1
Sockets
5
per cabinet
3,000 Wh · 3,000 W
Weight
294 kg
External
754 × 711 × 762 mm
Internal
452 × 566 × 471 mm
Article no. I/O30
B470006.01.01 / .02 / .03
Article no. I/O60
B470001.01.01 / .02 / .03
Technical data batrea 1, 2 and 3 (source: data sheets batrea I/O30 and I/O60)
1 batrea 12 batrea 23 batrea 3
Article no. I/O60B470001.01.01 / .02 / .03B470002.01.01 / .02 / .03B470003.01.01 / .02 / .03
Article no. I/O30B470006.01.01 / .02 / .03B470007.01.01 / .02 / .03B470008.01.01 / .02 / .03
Sockets5 pcs15 pcs25 pcs
Storage levels / shelves1 / 03 / 25 / 4
Max. energy per storage level3,000 Wh3,000 Wh3,000 Wh
Max. energy per cabinet3,000 Wh9,000 Wh15,000 Wh
Max. charging power per level3,000 W3,000 W3,000 W
Max. charging power per cabinet3,000 W3,680 W3,680 W
Load per shelf100 kg100 kg100 kg
Body height704 mm1,219 mm1,919 mm
Height of exhaust connectionmin. 50 mmmin. 50 mmmin. 50 mm
Overall height754 mm1,269 mm1,969 mm
Body width711 mm711 mm711 mm
Width of ventilation spigot–22 mm22 mm
Overall width711 mm733 mm733 mm
Body depth702 mm702 mm702 mm
Handle depth60 mm60 mm60 mm
Overall depth762 mm762 mm762 mm
Internal dimensions (H × W × D)452 × 566 × 471 mm966 × 544 × 471 mm1,666 × 544 × 471 mm
Door clearance (H × W)374 × 462 mm889 × 462 mm1,589 × 462 mm
Weight294 kg450 kg630 kg

Suffix .01 = type E · .02 = type F · .03 = type G

Classes I/O30 and I/O60

Both classes are tested and certified to VDMA standard sheet 24994:2024-08. Chapter 3 explains what the classes mean. Certification scope per size according to the certificates available:

batrea 2 and 3 in class I/O60 are listed in the data sheet; their certification status is confirmed on request.

Four articles are currently listed on mueller-safe.de, all with socket type F. Availability of further variants and socket types on request.

Socket types

The suffix of the article number denotes the socket type inside the cabinet. It follows the country of installation.

  • .01 Type EPoland, France, Belgium, Czech Republic, Slovakia
  • .02 Type FGermany, Austria, Netherlands, Sweden, Spain, Portugal
  • .03 Type GUnited Kingdom, Ireland, United Arab Emirates, Singapore

Under its terms and conditions Müller Safe delivers within Germany as a rule; deliveries to other countries by individual agreement. Please ask.

Product pages on mueller-safe.de: batrea category with all listed articles (currently populated on the German site only)

Which size fits?

Three answers give a first recommendation. It does not replace advice and contains no price or availability statement.

Without JavaScript the recommendation appears on this page after submitting.

How much energy do the batteries hold in total that will sit in the cabinet at the same time?

Watt-hours (Wh) are printed on the battery. Example: ten power tool batteries of 90 Wh each make 900 Wh.

How many chargers should be plugged in at the same time?
How much height is available at the installation site?

Frequently asked questions

01

What is the difference between I/O30 and I/O60?

Under VDMA 24994 both classes denote a passed internal fire test ("I") and differ in the duration of the additional external fire test: 30 or 60 minutes of protection of the batteries against a fire from outside. Which class suits a location depends on surroundings, fire load and insurer requirements. The data sheets available do not document a difference in the construction of the two batrea classes; we clarify this in conversation.

02

Do I need an exhaust air system?

Yes. According to the manufacturer's quick guide the cabinet must be connected to a suitable ventilation system. The connection is DN100 and the minimum air flow is 30 m³ per hour. In an emergency the ventilation flap closes automatically. The ventilation system itself is planned and installed on site.

03

How many batteries fit into a batrea?

That follows from the energy: a maximum of 3000 Wh and 3000 W charging power per storage level and 100 kg per shelf. batrea 1 has one level with 5 sockets (3000 Wh), batrea 2 three levels with 15 sockets (9000 Wh), batrea 3 five levels with 25 sockets (15000 Wh). The size finder on this page works it out for you.

04

Can batteries be charged inside the cabinet?

Yes. batrea is a storage cabinet for storing and charging lithium-ion batteries. Charging runs through the sockets inside the cabinet and is switched with START and STOP on the control panel; with the door open, charging does not start.

05

Does the cabinet replace a risk assessment?

No. The risk assessment remains the operator's duty. A certified storage cabinet is a technical protective measure that is documented in it and makes the protection level easier to assess.

06

What will my property insurer say?

In Germany, the insurers' guideline VdS 3103 places lithium batteries above 100 Wh in the medium power class and calls for fire-separated storage areas or clearances from combustible material. A cabinet certified to VDMA 24994 with a certificate on file is a solid basis for the conversation with the insurer; acceptance in the individual case rests with the insurer.

07

How does a 630 kg cabinet get to the first floor?

By freight forwarder with lifting equipment, after checking the transport route, door widths, lift and floor load capacity. Müller Safe collects these details with its transport and anchoring questionnaire; transport to upper floors and anchoring are agreed per site.

08

What actually happens in case of fire?

The control panel first reports a raised temperature (warning, 50 °C), then smoke or critical temperature (alarm, 60 °C) with a continuous tone; the ventilation flap closes automatically. The cabinet is designed to contain a possible fire inside. The door stays shut, people keep their distance and call the emergency number if they see smoke or fire.

09

As a reseller, can I get terms, a price list and a display unit?

Terms, price list, sample units and sales material are discussed directly with you. Use the dealer enquiry on this page or call us; the data sheets are available for download without a form so that you can pass them on to your customers.

Advice and enquiry

Two routes for the trade, one for operators. Choose your topic; the fields adapt.

01Specialist trade and resellersRange listing, terms and price list, sample units, sales material, logistics.Send dealer enquiry 02Technical advice and callbackInstallation site, exhaust air, capacity, choice of class, tender texts. We call you back.Arrange a callback
Your request
About your business
Interested in
About the project
Contact

Purpose: handling your enquiry by Müller Safe GmbH. Required fields are marked. No disclosure to third parties.

Documents

Data sheets are available without a form so that resellers can pass them on. Missing documents are marked "on request" and are not claimed.

  • Data sheet Data sheet batrea I/O30 German · PDF · 354 KB · Version not stated · File date 17 September 2026 Download
  • Data sheet Data sheet batrea I/O60 German · PDF · 354 KB · Version not stated · File date 17 September 2026 Download
  • Data sheet Data sheet batrea (English) English Request (on request)
  • Operating manual Operating manual batrea German Request (on request)
  • Certificate ECB•S certificates English Request (on request)
  • Transport and anchoring questionnaire Transport and anchoring questionnaire German · PDF · 386 KB Download

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