Four Facts to Confirm Before Reviewing Stack Capability

Do not start by asking whether a carton has a “3 m certificate.” Start with four shipment-specific facts:

1. Chemistry and UN entry: lithium ion or lithium metal, with the responsible party's supplied UN classification.
2. Physical configuration: batteries shipped alone, packed with the equipment they power, or contained in that equipment.
3. Packing instruction and section: the branch identified under the complete rules by appropriately trained personnel.
4. Completed-package identity: outer packaging, dimensions, material, closure, inner arrangement, orientation, contents and gross mass as prepared for transport.

A product name, stock-keeping unit, carton code or previous airline booking cannot determine the applicable rule by itself. For help separating the main configurations, see UN3480 vs UN3481 for lithium ion and UN3090 vs UN3091 for lithium metal.

What the Lithium Battery 3 m Stack Requirement Means

The requirement is intended to establish that an applicable package can sustain a defined top load without allowing the batteries to be damaged or the packaging to become less effective. Five elements belong together:

• the package or completed package specified by the applicable branch;
• a force applied to the top surface;
• a force equivalent to the total weight of identical packages stacked to 3 m, including the package under evaluation;
• a duration of 24 hours; and
• no battery damage and no reduction in package effectiveness.

The wording does not necessarily require a warehouse to build a physical tower exactly 3 m high. IATA gives both physical stacking and an equivalent applied top load as possible testing examples. It also recognizes assessment and relevant experience as possible ways to establish capability. What matters is an objective, traceable basis tied to the actual package and the conditions it represents.

Do not reduce the requirement to a carton compression number without technical comparison. A supplier's box specification may be part of the evidence, but the completed package also depends on closures, inserts, cushioning, equipment, battery position, orientation, gross mass and how the load is transferred through the structure.

Which Lithium Battery Air Packing Branches Require It?

The following table is an orientation map for the current 2026 context. It is not the complete text of any packing instruction and does not authorize a shipper to select a section without competent review.

Sources: IATA's 2025 interpretation of the lithium-battery 3 m stack requirement and its 2026 Battery Guidance Document.

The table deliberately does not reproduce every threshold, exception or packaging condition. A branch can change because of battery chemistry, Watt-hour rating, lithium content, configuration, quantity, test status or another provision. The complete effective instructions and applicable variations control the shipment.

Section IB and the 2025 Equipment-Package Addition Are Different Pathways

Two histories are often collapsed into one statement.

First, the 2026 IATA battery FAQ identifies the 3 m stack-capability condition for PI 965 and PI 968 Section IB—standalone lithium-ion and standalone lithium-metal batteries within those branches.

Second, IATA issued a dedicated interpretation for an additional condition effective in January 2025 for specified non-UN Specification packaging used for lithium batteries packed with or contained in equipment: PI 966 Section II, PI 967 Sections I and II, PI 969 Section II, and PI 970 Sections I and II.

Therefore, “new in 2025” should not be used as though the entire lithium-battery stack requirement began then. Nor should the equipment-package addition be applied to every lithium-battery package. Identify the applicable branch first, then read the requirement that belongs to that branch.

This distinction also matters for version control. The ICAO 2025–2026 edition expires at the end of 2026. Any publication or shipment prepared under a later edition must be rechecked against the new text rather than relying on this dated map.

Which Package Must Be Capable?

In dangerous-goods language, IATA's 2026 packaging FAQ defines a package as the complete product of the packing operation that satisfies the applicable instruction and is ready to be presented for transport. For this review, identify the exact physical unit to which the applicable instruction attaches the capability condition.

That description should include:

• the outer packaging manufacturer, style, material and dimensions;
• the closure method, including tape, staples, straps or other specified components;
• inner packaging, trays, dividers, cushioning and void fill;
• battery and equipment arrangement;
• package orientation during the evaluation;
• representative or limiting contents; and
• gross mass of the completed package.

Gross package mass is not the same as net battery quantity. Gross mass includes the batteries, equipment, inner materials and outer packaging. Net battery quantity is a separate regulatory input discussed in the guide to lithium battery air shipping quantity limits.

Evidence for an empty carton does not automatically represent a completed package. Evidence for a light product may not represent a denser product in the same carton. A change to the insert or closure can also change how the load is transferred. For broader guidance on terminal protection, cushioning, movement prevention and package photographs, use the separate lithium battery packaging guide.

Testing, Assessment and Experience Are Three Possible Evidence Routes

IATA's dedicated interpretation does not prescribe one universal route. It names testing, assessment and experience. Each route still needs a documented connection to the package being offered.

1. Testing

A testing route may use representative packages prepared for transport and stacked for 24 hours, or apply an equivalent force to the top of a representative package. The record should identify the complete design, contents, orientation, gross mass, applied load, duration and observations.

For a family of products, define the limiting basis. IATA's example says a retailer using several representative product lines should use the products with the greatest density or restrict the per-package weight to the tested basis. “We tested one box” is not enough if no one can show which box, contents or weight the result covers.

2. Assessment

For packaging designed for a specific product, the original packaging designer or manufacturer may provide an expert assessment. The assessment should identify the exact packaging, product arrangement, material specifications, closures, orientation, mass limit and assumptions. A generic marketing statement about carton strength is not automatically a package-specific assessment.

3. Experience

Documented experience from comparable warehousing or transport operations may support capability when the same or genuinely representative packages have routinely been stacked under equal or more demanding conditions. Record the package design, contents, orientation, stack conditions, duration, dates and any damage or deformation observations.

A sentence saying “this product shipped before” is not comparable evidence unless the underlying conditions can be traced. A prior shipment might have used a different supplier, carton grade, gross mass, pallet pattern or storage duration.

Whichever route is selected, retain the evaluation basis. IATA says the shipper should be able to provide that basis if requested by the appropriate regulatory authority.

Does the Package Need an Independent Laboratory Certificate?

Not as a universal requirement under the cited IATA interpretation. IATA states that there is no formal universal requirement for the test to be conducted by an independent testing authority, and it does not prescribe a special conditioning method for this capability demonstration.

That does not mean evidence is optional, that any self-declaration is sufficient or that a carrier must accept the record. The shipper remains responsible for ensuring that the packaging and completed package meet the applicable dangerous-goods requirements.

Independent help may still be sensible when:

• the design is new or technically complex;
• the package family covers a wide range of dimensions or masses;
• the supplier's specification cannot be linked to the completed package;
• material performance may be affected by moisture, storage or reuse;
• a customer, authority, operator or internal quality system asks for more formal evidence; or
• the consequences of an incorrect assessment justify a packaging engineer or laboratory review.

Use accurate names for the resulting records. A laboratory report, designer assessment or internal capability record should not be advertised as an “IATA certificate” unless an official document with that exact status actually exists. BAT Logistics does not issue an IATA, ICAO or government stack-test certificate.

Building the Equivalent Top-Load Basis

The load basis starts with identical packages, the package height in the assessed orientation and the gross mass of the representative completed package. The 3 m concept includes the package being evaluated; when a separate equivalent weight is applied to its top, the weight representing packages above it is derived from the documented stack basis.

Do not use an online calculator before the design assumptions are fixed. Small differences in package height, orientation, gross mass and how partial layers are treated can change the proposed load. The responsible technical reviewer should document the method and any conservative rounding.

Fictional arithmetic example—not a pass/fail decision

Assume a representative completed package is 0.40 m high in the assessed orientation and has a gross mass of 18 kg.

• Nominal number of package heights in 3 m: 3.00 ÷ 0.40 = 7.5
• A documented conservative stack basis might round this to 8 identical package positions, including the sample.
• Packages represented above the sample: 8 − 1 = 7
• Equivalent mass placed above the sample: 7 × 18 kg = 126 kg

Arithmetic check: 0.40 m × 8 = 3.20 m, and 18 kg × 7 = 126 kg.

This example shows how assumptions can be recorded. It does not prescribe the rounding method, convert mass to an engineered force, account for load-distribution fixtures or prove that the package passes. A responsible packaging or dangerous-goods professional must determine the applicable method and acceptance observations for the actual package.

A useful record should state the package height, orientation, gross mass, stack-count logic, applied top load or force, loading arrangement, start and finish times, and the condition of the package and batteries after the evaluation.

3 m Stack Capability Is Not the 1.2 m Drop Requirement

Stack and drop conditions answer different physical questions. Evidence for one should not be substituted for the other.

The IATA 2026 packaging FAQ discusses the 1.2 m drop question separately from the 3 m Section IB question. It explains that the completed package prepared under the relevant packed-with-equipment instruction must meet the applicable drop capability. That separate discussion is a warning against treating one result as universal packaging proof.

UN 38.3 is different again. It concerns the cell or battery design type under the UN Manual of Tests and Criteria, not the transport package's 3 m top-load capability. A valid UN 38.3 test summary cannot replace the package evidence discussed here.

Package, Pallet and Overpack Are Not Interchangeable

A package is the completed unit produced by the packing operation and prepared for transport. An overpack is an enclosure used by one shipper to contain one or more packages and form a convenient handling unit. A palletized load may be an overpack, but the exact status depends on how it is prepared.

An overpack does not repair an inadequate package. Each package inside must already meet its applicable packing requirements and remain in proper condition. Securing packages to a pallet must not crush them, obscure required information without correct repetition or otherwise impair their intended function.

Routine pallet stacking can be relevant to an experience-based capability case only when the package and conditions are comparable and documented. A photograph of a pallet that is 1.5 m high does not by itself establish the equivalent 3 m condition. Nor does stacking two pallets prove that the load reached each package in the same way as the assessed configuration.

Marks, labels and information repeated on an overpack are separate hazard-communication decisions. See the guide to lithium battery marks and labels rather than using a stack record to infer marking relief.

What a Defensible Capability Record Should Contain

The following 14 fields provide a practical internal evidence record. They are not an official IATA form or a certificate template.

1. Product or shipment identifier linking the record to the item being offered.
2. Responsible classification input, including chemistry, supplied UN entry and physical configuration.
3. Packing instruction and section identified under the effective rules by appropriately trained personnel.
4. Exact package design and supplier, including model, style or drawing number.
5. Dimensions and material, including relevant grade or construction specification.
6. Closure method and any required tape, staples, straps or fasteners.
7. Inner arrangement, including battery, equipment, tray, divider, cushioning and void-fill positions.
8. Package orientation used for the evaluation and intended transport preparation.
9. Representative contents and gross mass, including any limiting-density or maximum-weight basis.
10. Evidence route: testing, assessment or relevant experience.
11. Load and duration basis, with the identical-package logic, applied load or force and 24-hour period.
12. Result or assessment statement, including observed damage, deformation and package-effectiveness criteria.
13. Supporting records, such as photographs, drawings, supplier statements, dates, versions and responsible reviewer.
14. Change and re-evaluation triggers for design, material, contents, mass, supplier or regulatory changes.

Store this record with the broader lithium battery shipping documents for the shipment or approved package family. Keep the scope visible so that users do not apply the evidence to a different package by convenience.

When the Package Should Be Re-Evaluated

Re-evaluate the basis when a change could affect the load path, package strength, battery protection or rule applicability. Common triggers include:

• a different carton grade, material, construction method or supplier;
• changed external dimensions, closure, tape specification, strap pattern or orientation;
• a new inner tray, divider, cushioning system, equipment arrangement or void-fill method;
• a higher product density or completed-package gross mass;
• a changed battery model, chemistry, configuration, UN entry, packing instruction or section;
• moisture exposure, storage damage, repeated reuse or another condition not represented by the evidence;
• an untraceable report or assessment that cannot be connected to the offered package;
• a new ICAO/IATA edition, addendum, corrigendum, State variation or operator requirement; or
• a carrier, handler, authority or internal quality reviewer requesting updated support.

Not every minor administrative change demands a new physical test. The responsible reviewer should assess whether the change affects the documented design or its limiting assumptions and record that decision.

Common 3 m Stack-Test Errors

Assuming every lithium-battery package uses the same requirement

Applicability follows the current packing instruction and section, not the fact that a product contains a lithium battery.

Using a product name to select a packing section

“Laptop battery,” “power bank” or “battery-powered tool” is not enough. Chemistry, configuration, rating or content, test status and other conditions affect the branch.

Treating 3 m as only the height of the shipped pallet

The condition describes an equivalent stack load on the applicable package. The actual pallet height is not the complete question.

Evaluating an empty box or a non-representative light package

The completed package, contents and limiting gross mass determine whether evidence represents the offered configuration.

Ignoring orientation, closures or inner arrangement

Changing any of these can change the load path and the protection provided to the batteries.

Substituting a 1.2 m drop record

Impact capability does not establish sustained top-load capability for 24 hours.

Calling a generic carton certificate an IATA stack-test certificate

The cited IATA interpretation does not create a universal independent-certificate format.

Applying evidence from one design or supplier to another

Similar dimensions do not prove equivalent materials, joints, manufacturing quality or completed-package performance.

Using an old successful shipment as undocumented experience

Experience is useful only when the comparable package and conditions can be traced.

Confusing gross package mass with net battery quantity

The stack basis and the regulatory net battery limit use different values for different purposes.

Treating an overpack as a cure for an inadequate package

Packages inside an overpack must already comply with their applicable preparation requirements.

Assuming capability evidence guarantees airline acceptance

Authorities, States, operators, handlers and routes may impose or apply additional conditions. Evidence addresses one package question, not the complete acceptance decision.

What the Stack-Capability Result Cannot Decide

A package-capability record does not by itself determine:

• final classification, UN number, packing instruction or section;
• UN 38.3 design-type status or the availability of a test summary;
• Watt-hour rating or lithium-content inputs;
• required state of charge;
• battery count or net quantity per package;
• short-circuit protection, cushioning or prevention of unintended activation;
• marks, labels, declarations or air-waybill statements;
• State or operator variations, approvals or exemptions;
• route, facility, handler or airline acceptance; or
• customs and destination requirements.

Treat stack capability as one controlled field in the shipment record. It cannot make an otherwise ineligible battery, package or route acceptable.

Pre-Enquiry Package-Capability Checklist

Before asking a forwarder, dangerous-goods specialist, packaging professional or airline to review the shipment, confirm that:

• the exact battery chemistry and physical configuration are known;
• the responsible party has identified the current packing instruction and section;
• the offered package matches the documented package design and supplier;
• the contents, orientation, closure and gross mass are recorded;
• the applicable 3 m stack-capability condition has been checked;
• testing, assessment or experience is identified as the evidence route;
• the equivalent load basis and 24-hour duration are traceable;
• any designer or manufacturer assessment identifies the covered design and limits;
• any experience record describes comparable package and stacking conditions;
• 1.2 m drop and UN Specification evidence are kept separate;
• package, pallet and overpack levels are not confused;
• changes since the evidence date have been reviewed; and
• current State/operator variations and route acceptance remain open until confirmed.