In short
Of the three documents quoted on battery cabinet datasheets, only VDMA 24994 was written for lithium battery cabinets. EN 14470-1 covers flammable liquid cabinets and tests a fire outside the cabinet. UL 9540A is a test method for energy storage systems, not cabinets. None is required by UK law.
This page exists because these three references get used interchangeably in sales material, and they are not interchangeable. Understanding which test applies fire from the outside and which starts it on the inside is enough to read most datasheets correctly.
| Document | Status | Written for | How fire is applied in the test | Where the dispute lies |
|---|---|---|---|---|
| EN 14470-1 | European standard | Safety storage cabinets for flammable liquids | Fire outside the cabinet; the test measures how long the contents stay below a defined temperature rise | Widely quoted for battery cabinets because the type 15/30/60/90 classification is familiar to buyers. Its applicability to lithium batteries is disputed, because a battery fire starts inside the cabinet rather than outside it. |
| VDMA 24994 | German industry specification, not a UK or BSI standard | Storage and charging cabinets for lithium batteries | Thermal runaway initiated inside the cabinet | Addresses the failure mode that matters for batteries, but it is a trade-association specification rather than a harmonised standard, and it is not referenced in UK legislation. |
| UL 9540A | US test method | Battery energy storage systems (BESS) | Cell, module and unit-level thermal runaway propagation | Sometimes cited on portable cabinet literature. It was not written for cabinets of loose batteries, so a UL 9540A reference on a cabinet datasheet does not describe that cabinet’s performance. |
EN 14470-1 in more detail
EN 14470-1 is a European standard for fire-resistant safety storage cabinets for flammable liquids. Cabinets are classified by how long the interior stays below a defined temperature rise while a fire burns outside — the familiar type 15, 30, 60 and 90 designations, in minutes.
It is a real standard, properly constructed, and its classification is genuinely useful information: a type 90 cabinet will keep its contents cooler for longer in a building fire than a type 30 will. The problem is scenario mismatch. A flammable liquids cabinet is designed to stop an external fire reaching the contents. A battery cabinet needs to stop an internal fire reaching the building. Those are different jobs, and a test of the first does not measure the second.
This is where the industry genuinely disagrees, and it is worth stating both positions. One view holds that EN 14470-1 construction is a reasonable proxy — a cabinet built to resist 90 minutes of external fire is substantially built, and that substance helps in either direction. The other holds that the test says nothing about internal pressure, gas venting or propagation between packs, so quoting it for a battery cabinet is misleading by omission. Both arguments have merit. Neither is settled.
VDMA 24994 in more detail
VDMA 24994 was published by the VDMA, the German mechanical and plant engineering trade association. It sets out safety requirements and test arrangements specifically for cabinets used to store and charge lithium batteries, and critically it initiates the thermal runaway inside the cabinet — the scenario the cabinet actually exists for.
Two caveats, stated plainly. It is a trade-association specification rather than a harmonised European or British standard, which affects its formal weight even though its technical content is on point. And it is not referenced anywhere in UK legislation, so testing to it is evidence rather than compliance. What it gives you is the most relevant available answer to “does this cabinet contain a battery fire”, which is worth more in a risk assessment than a more formal standard testing the wrong scenario.
UL 9540A in more detail
UL 9540A is a US test method for evaluating thermal runaway fire propagation in battery energy storage systems — the large installed systems used for grid and building energy storage. It tests at cell, module and unit level and produces data used by designers and fire authorities for those installations.
It is not a cabinet standard, and it is not a product certification. When UL 9540A appears on literature for a cabinet holding loose e-bike packs, one of two things is happening: the reference belongs to a cell or module inside a different product entirely, or it is being used as general reassurance. Either way it does not tell you how that cabinet performs. Ask what the cabinet itself was tested to.
What to ask a supplier
- Which standard or specification was this cabinet tested to — not the range, not a comparable model?
- Was the fire started inside the cabinet or outside it?
- Which test house carried out the test, and can I see the report or a summary?
- What duration was achieved, and what was the pass criterion?
- What was inside the cabinet during the test, and how does that compare with what I intend to store?
- If it is a charging cabinet, was it tested with power applied?
A supplier who can answer all six in writing is straightforward to deal with. One who cannot answer question two has told you what you need to know.
Frequently asked questions
Is VDMA 24994 a British Standard?
No. VDMA 24994 is a German industry specification published by the VDMA trade association. It is not a BSI standard, not a harmonised European standard, and not referenced in UK legislation. Its value is technical relevance rather than formal status: it tests the failure mode that battery cabinets exist to contain.
Is an EN 14470-1 type 90 cabinet suitable for lithium batteries?
It may be a reasonable control, but the type 90 rating is not evidence for it. That rating describes performance against a fire outside the cabinet. If you are relying on the cabinet to contain a fire starting inside it, ask for test evidence for that scenario. Using a type 90 cabinet is a defensible decision; quoting the rating as proof of battery fire containment is not.
Which standard should I specify in a tender?
For cabinets storing or charging loose lithium battery packs, VDMA 24994 is the most directly relevant document to name, because its test scenario matches the risk. It is reasonable to accept EN 14470-1 classification alongside it as construction evidence. Specify the outcome as well as the standard — internal capacity in watt-hours, whether charging is included, and what detection is provided — so that bids are comparable.
Why is there no British standard for battery cabinets?
Standards development lags the market, and lithium battery storage as a distinct workplace problem is recent. The gap is why a German trade-association specification has become the de facto reference in the UK. It is a reasonable interim position, and it is worth re-checking periodically — this is an area where a formal standard would change the answer to the previous question.