Portable Power Stations: UN 38.3 Decides How They Travel

A quarry decides to retire the small diesel set at an exploration camp and run the survey crew on six portable power stations and a solar charging kit. The requisition reads like equipment, because that is what it is, and the schedule is built on an air transit because the crew mobilises in five weeks. Then the forwarder asks for the UN 38.3 test summary for the battery inside each unit, and the order stops. Nothing was specified wrongly: the requirement never named the one attribute that decides how the goods may travel.

A transport qualification, not a product safety mark

Lithium cells and batteries are accepted for transport only if they are of a type proved to meet Part III, sub-section 38.3 of the United Nations Manual of Tests and Criteria. The reference text is the eighth revised edition, as amended by Amendment 1, adopted by the Committee of Experts on 6 December 2024, which changes sub-section 38.3 among other sections. The sub-section sets eight tests, T.1 to T.8: altitude simulation, thermal test, vibration, shock, external short circuit, impact and crush, overcharge, and forced discharge.

That is a transport qualification and nothing more. IEC 62133-2, in its consolidated edition 1.1 of 15 July 2021, sets safety requirements for portable sealed lithium cells and the batteries made from them in portable use. Its scope says nothing about transport. A factory answering a request for UN 38.3 evidence with an IEC 62133-2 certificate has supplied a real document about a different question, and a buyer who files it has qualified the product rather than the shipment.

The qualification attaches to a design, not to a consignment. IATA guidance effective 1 January 2026 states that a design becomes a new type requiring new tests when it differs by more than 20 per cent in watt-hour rating, when nominal voltage rises by more than 20 per cent in rechargeable cells, or when any change might materially affect the results. Changes to electrode, electrolyte or separator material, to protective devices and to cell count or connection are each named, as is repair or remanufacture with non-original parts. A test summary holds until one of those changes happens. That is what turns a cell substitution agreed on the production floor into a consignment no forwarder will accept.

The test summary is the document to ask for

Since 1 January 2020 the ICAO Technical Instructions and the IMDG Code have required manufacturers and subsequent distributors of lithium cells and batteries to make a test summary available. Ten items are fixed: the manufacturer and the test laboratory with contact details, a unique test report number and its date, a description of the cell or battery giving lithium ion or lithium metal, mass, watt-hour rating or lithium content and the model number, the tests run with a pass or fail against each, the assembled battery provisions where they apply, the revision of the Manual and any amendments used, and the name and title of a responsible person.

Two entries do most of the work. The model number has to be the unit being offered, not a near relative in the same family. The revision reference matters because the edition in force when a design was first tested is the edition that governs it, so a summary citing no revision cannot be checked. No format is mandated, any party in the chain may ask for it, and a link or a QR code satisfies the obligation.

Sea transport tightened the obligation this year. IMDG Code amendment 42-24, adopted by the International Maritime Organization as resolution MSC.556(108) in May 2024 and mandatory from 1 January 2026, clarified what making a summary available means: it has to be accessible so that consignors and others in the chain can verify compliance.

Where the freight plan actually breaks

The figure that decides everything is the watt-hour rating. By air, batteries contained in equipment travel under packing instruction 967, which splits at 100 watt-hours for a battery and 20 watt-hours for a cell. Below the split a package is limited to 5 kg on passenger and cargo aircraft alike. Above it, Section I applies: United Nations specification packaging, 5 kg per package on a passenger aircraft and 35 kg on cargo aircraft only. A power station rated at several hundred watt-hours sits well above the split, and once unit and packaging exceed 5 kg it cannot be prepared for a passenger aircraft under that section at all.

Send a battery on its own and the picture changes again. A spare pack, or the battery element of a solar kit shipped loose, is UN 3480 under packing instruction 965. Lithium ion batteries shipped alone are forbidden as cargo on passenger aircraft, a restriction in force since 1 April 2016, and must be offered at a state of charge not exceeding 30 per cent of rated capacity. Anything higher needs written approval from the State of Origin and the State of the Operator. Per package, Section IA allows 35 kg and Section IB 10 kg, cargo aircraft only in both cases.

One detail catches buyers at receipt. Lithium ion batteries in Section I manufactured after 31 December 2011, and those in Section IB and Section II manufactured after 1 January 2009, must carry the watt-hour rating on the outside of the case. A unit that arrives without it is not a labelling problem to close out with a sticker. It is a question about what was tested.

What the requirement should have said

Three habits produce this outcome. The first is buying on output: a specification that names continuous watts, surge watts and inverter waveform, and never names the watt-hour capacity of the pack or its cell chemistry, has left the transport classification undetermined. The second is accepting the wrong evidence: a product safety certificate filed where a test summary should be. The third is adding spare packs to the same consignment without saying so, which turns one shipment of equipment into two regimes, one of which cannot fly on a passenger aircraft at all. Behind all three sits arithmetic nobody runs: a unit rated at 500 watt-hours sits at five times the threshold that separates the light regime from the full one.

How we run it

We settle the electrical specification before anyone quotes: watt-hour rating per unit, cell chemistry and format, continuous and peak output, and whether spare packs are in scope. Those four lines fix the classification, the classification fixes the mode, and transit time is derived rather than assumed. We ask for the test summary at quotation rather than at despatch, and read it against the offer: report number and date, the revision of the Manual cited, the model number matching the unit quoted, the mass and watt-hour rating matching the data sheet, and all eight tests with a result.

We then fix the cell and the pack by model in the order, so a substitution becomes a change the buyer agrees to rather than a document that quietly stops being valid. The watt-hour marking on the case, the state of charge at despatch, the packaging specification against the section that applies, and who prepares the declaration all go into the purchase order. Production follow-up checks them at the factory, where a missing marking is a production problem, rather than at the port, where it is a detained container. None of this is legal advice, and the position for any particular consignment rests with the carrier, the forwarder and the competent authorities involved.

What to send us

If you are buying portable power for a remote site, send the watt-hour rating and output you need per unit, the number of units, whether spare battery packs are included, the destination and whether it is reachable by sea or has to move by air, the required on site date, and any site constraint such as ambient temperature or charging source. We will come back with the classification the goods fall into, the packing instruction and section that follows, the per package limits, the documents we will require from the factory, and the lead time that mode implies. Submit the requirement and that work happens before anyone quotes a price, because a price that assumes the wrong freight mode is not a quotation. It is a schedule waiting to slip.