Marking and Labelling Lithium Battery Shipments

1. Why Marks and Labels Cause So Many Battery Rejections

Marks and labels are the only part of a dangerous goods consignment that every person in the chain actually sees. The driver, the terminal operative, the stevedore and the ramp agent will never open the package or read the packing instruction. They rely on what is printed on the outside to decide how to load it, what to keep it away from and what to do if something goes wrong. That is why carriers and enforcement officers check marks first, and why a missing or outdated mark so often stops a battery consignment.

Batteries make this harder than most dangerous goods. The same product can need different marks depending on whether it is shipped alone, with equipment or in equipment; whether it is a small or fully regulated battery; whether it is new, damaged or going to a recycler; and which mode it travels by. The rules also changed in 2025.

• Who this guide is for. Shippers and packers who prepare the package, warehouse dispatch teams who release it, acceptance staff at forwarders and carriers who check it, and the DGSAs who sign off the procedures.
• What it does not replace. The current text of ADR, RID, the IMDG Code and the IATA Dangerous Goods Regulations. Always check the edition in force for your shipment date.

Acceptance staff see the results of these mistakes every day, and the acceptance checks at a forwarder’s desk start with exactly the items in this guide: does the outside of the package match the declaration?

2. The Building Blocks: Marks and Labels Explained

The regulations distinguish between marks (text and symbols such as the UN number or the battery mark) and labels (the diamond-shaped hazard labels and handling labels). A battery package draws on a small set of each. The table describes them in words; the artwork is set out in each regulation.

Two details are often missed. First, ADR allows other hazard labels to carry text such as the UN number, but the 9A label may contain only the stripes, the batteries and the class number. Second, all marks must be clearly visible, legible and weather-resistant (ADR 5.2.1.2). The IMDG Code goes further: package marks must remain identifiable after at least three months’ immersion in the sea.

None of these marks proves that the battery itself is fit to travel. The classification rests on the design type having passed the transport test series, and a desk that is checking marks should also be able to see UN 38.3 test summaries on request.

3. The 2025 Changes: One Mark, One Label, Two Chemistries

The 2025 editions of ADR and RID, Amendment 42-24 of the IMDG Code and the ICAO Technical Instructions brought sodium-ion cells and batteries into the dangerous goods system under their own entries, UN 3551 and UN 3552. Rather than create a parallel set of marks, the regulations widened the existing ones. In ADR the mark in 5.2.1.9 is now simply the battery mark, and the Class 9A label is now the lithium battery and sodium ion battery hazard label.

With the transition ending in under two months, now is the time to audit label stock, pre-printed cartons and templates in warehouse management and label-printing software.

For sodium-ion shippers, the change means the familiar mark is now correct for their batteries too, but only with the sodium-ion UN number on it. Anyone still working out where Na-ion batteries fit in Class 9 should settle the classification first, because the UN number on every mark and document follows from it.

4. Special Situations: Damaged, Waste, Prototype and Overpacked Batteries

Several provisions add their own text marks or document statements on top of the standard set. The exact wording matters.

4.1 Damaged and defective batteries (SP 376)

SP 376 applies to cells and batteries identified as damaged or defective so that they no longer conform to the tested type: batteries defective for safety reasons, those that have leaked or vented, those that cannot be diagnosed before carriage and those with external or mechanical damage. The package carries the full set of marks for its UN number, the Class 9A label and the SP 376 wording. Use the wording for the chemistry actually in the package, and never shorten it to “DAMAGED” or “DEFECTIVE” alone. The decision to apply SP 376 comes before any of this, and our guide to the condition assessment that triggers SP 376 explains how to make it. A common source of these packages is battery packs salvaged after road accidents, where condition is rarely known at the moment of dispatch.

4.2 Disposal and recycling (SP 377)

SP 377 lets lithium and sodium-ion cells and batteries sent for disposal or recycling be packed under P909, with or without non-lithium batteries, and relieves them of the usual classification conditions. In return, the package must carry the disposal or recycling wording. SP 377 does not cover batteries identified as damaged or defective: those must be moved under SP 376 and marked accordingly, even when their final destination is a recycler. Sorting a mixed collection into the right stream is the first step in collection and transport chains for spent batteries, and every stream needs its own marking.

4.3 Prototypes and small production runs (SP 310)

Under SP 310, pre-production prototypes transported for testing and production runs of not more than 100 cells or batteries are packed in accordance with P910 or LP905. SP 310 adds no package text, only the transport document statement. A damaged or defective prototype moves under SP 376 instead.

4.4 Overpacks

An overpack, such as cartons shrink-wrapped on a pallet, easily hides marks. Under ADR SP 188, when packages with the battery mark are placed in an overpack, the mark must either be clearly visible or be reproduced on the outside, and the overpack must be marked “OVERPACK” in letters at least 12 mm high. IATA’s 2026 guidance sets the same expectation for air, and the same logic applies to UN numbers and hazard labels on fully regulated packages.

5. Marking by Mode: Road, Rail, Sea and Air

The UN Model Regulations give all modes a common base, but the details differ. The comparison below covers the points that most often trip up multimodal shipments.

5.1 Road and rail

For Class 9 batteries ADR and RID require the UN number on the package but not the proper shipping name. The battery mark applies to packages prepared under SP 188 or SP 400. SP 188 also lists two exceptions: packages containing only button cells installed in equipment, and packages containing no more than four cells or two batteries installed in equipment, where the consignment has no more than two such packages.

5.2 Sea

The IMDG Code requires the proper shipping name next to the UN number on each package, for example “UN 3480 LITHIUM ION BATTERIES”, and its marks must survive three months in seawater.

5.3 Air

Lithium-ion and lithium metal batteries shipped by themselves (UN 3480 and UN 3090), and sodium-ion batteries under PI 976 (UN 3551), are forbidden on passenger aircraft, so their packages carry the Cargo Aircraft Only label. IATA’s 2026 guidance states that a Section IB package needs the UN number and proper shipping name, the shipper and consignee names and addresses, the net weight, the battery mark, the Class 9A label and the Cargo Aircraft Only label. The battery mark must not be applied under PI 976, Section IA of PI 965 and 968, or Section I of PI 966, 967, 969 and 970; those packages carry the 9A label instead. For a broader comparison of the codes, see why a sea booking differs from air.

6. Reading the Packaging’s Own UN Specification Mark

The packaging carries a mark of its own: the UN specification mark, showing that its design type has been tested and approved. Large packagings for damaged batteries under LP906 must be approved in their own right, and anyone familiar with fire-test approval for damaged-battery packaging will know that the mark is the visible end of that process. ADR 6.6.3.1 sets out eight elements, in fixed order, separated by slashes or spaces.

1. (a) The UN packaging symbol, or “UN” where stamped or embossed on metal.
2. (b) “50” (rigid) or “51” (flexible), plus a material letter: A steel, B aluminium, H plastics.
3. (c) The packing group letter: X for packing groups I, II and III; Y for II and III; Z for III only.
4. (d) The month and year (last two digits) of manufacture.
5. (e) The authorising State, by its international vehicle distinguishing sign.
6. (f) The manufacturer’s name or symbol and identification specified by the competent authority.
7. (g) The stacking test load in kg, or “0” if not designed for stacking.
8. (h) The maximum permissible gross mass in kg.

6.1 Worked example: a BUNCKER® Model M

Here is how to read the mark on certified large packaging, using a BUNCKER® Model M as an example. Its published specification mark is UN 50A/X/--**/B/1655.2144-230139/2175/1208.

A product page cannot show a real date in element (d), because the date belongs to each unit; the plate on a physical unit should show actual digits there. If it does not, query it before use.

6.2 Why the maximum permissible gross mass matters

Element (h) is the figure loading teams most need: the total mass of packaging plus contents. For the Model M, the published Model M datasheet gives an empty weight of 508 kg and a maximum battery weight of 700 kg, which adds up to the 1,208 kg on the mark. The same relationship holds across the range: the Model S mark ends in 800 (365 kg empty plus 435 kg of batteries) and the Model XXL in 2660 (1,120 kg plus 1,540 kg). In practice: weigh the battery and any securing material, add the empty weight and check the total against element (h). An overweight package is outside its approval, however well it is marked.

Element (g) is different. It records the load applied in the design type stacking test; it is not an instruction to stack loaded units to that weight in service. Follow the manufacturer’s instructions and the certificate for stacking in use. The certificate also defines what may go inside, so check the BUNCKER® LP906 approval scope against the batteries you intend to pack.

The 90 kWh Model M is one of six Pro Line Heavy units, all UN LP906 certified for road (ADR), sea (IMDG) and rail (RID) and for indoor and outdoor storage, alongside the side-loading SDR (45.8 kWh) for batteries in any status and the S (50 kWh), L (90 kWh), XL (100 kWh) and XXL (200 kWh). The BUNCKER® range from SDR to XXL lists the specification mark for each. Every unit uses a patented bell jar with no filler materials and a Fibercon Altilium® CP Blanket (FACB) that neutralises HF, keeps its outer surface below 100 °C during a full thermal runaway, and is made in the Netherlands by VDL.

Worked example

Model M: A Specification Mark You Can Check

The BUNCKER® Model M is a UN LP906 certified large packaging for road, sea and rail transport and for indoor and outdoor storage, rated at 90 kWh with a 700 kg maximum battery weight. Its UN specification mark and datasheet values are published, so loading teams can check gross mass before dispatch.

See Model M specifications →

7. Common Mistakes and How to Catch Them Before Dispatch

Most marking errors come from old label stock, outdated templates, or a package that changed provision or mode without being re-marked.

Reusable units deserve particular attention in programmes that move many packs on fixed routes, such as retired energy storage modules on the road to treatment sites, where the same unit may leave as an SP 376 package and return empty. Marking is also easier when the packaging fits the battery well in the first place; if you are still selecting a container for large packs, check that its gross mass and certificate cover your heaviest battery.

8. Pre-Dispatch Marking Checklist

Use this list at the packing bench and again at the dispatch door, once classification and packing instruction are confirmed.

• ✅ UN number correct. Matching the battery type and configuration, with the “UN” prefix and the right character height?
• ✅ Proper shipping name where needed. Is the proper shipping name on the package for sea and air legs?
• ✅ Right mark or label. Battery mark for small battery provisions; Class 9A label for fully regulated batteries; never the battery mark on PI 976 or Section IA air packages?
• ✅ Current version only. No battery mark with a telephone number after 31 December 2026?
• ✅ Size and legibility. Battery mark at least 100 × 100 mm (or 100 × 70 mm where the package requires it), labels at least 100 × 100 mm, all weather-resistant and unobstructed?
• ✅ Cargo Aircraft Only label. Applied to every PI 965 and PI 968 Section IA and IB package and every PI 976 package going by air?
• ✅ Special wording. SP 376 or SP 377 text applied exactly, for the right chemistry, and the matching statement on the transport document?
• ✅ Large packagings. Marks and labels on two opposite sides, and the UN specification mark on the packaging legible with a real date of manufacture?
• ✅ Gross mass. Battery plus packaging plus securing material within the maximum permissible gross mass on the specification mark?
• ✅ Overpacks. “OVERPACK” applied and all inner marks and labels visible or reproduced?
• ✅ Old marks removed. Nothing on the package that describes a previous load?