Shipping Lithium Batteries: UN3480 vs UN3481 Packing Rules

Sixteen cartons of replacement power-tool packs reach the airline's cargo acceptance desk on a Friday evening. The cartons carry the lithium battery mark, the paperwork says UN3481, and the shipment is refused within ten minutes: the packs were boxed on their own, not with the tools, so the correct entry was UN3480, which no passenger aircraft may carry and which must travel at no more than 30% charge. The truck goes back, and the customer's weekend repair clinic opens without stock.

Lithium battery shipping rules are not hard once three facts are fixed for each SKU: chemistry, how the battery travels relative to the equipment, and its watt-hour rating or lithium content. Store those facts in the item master, and dispatch can choose the UN number, packing instruction, mode and carton count by rule instead of by memory, with fewer refusals and repacks.

• What this guide covers: UN3480 versus UN3481, the 20 Wh and 100 Wh lines, state-of-charge limits by air, marks and labels, and the US ground exceptions under 49 CFR 173.185, with India's road and air position.
• What it adds: a classification formula, a carton-count calculation, an air-versus-road cost comparison in $ and ₹, a refused-shipment trace and a dispatch checklist.

Three facts that put a battery shipment under the right UN number

Chemistry and packaging relationship choose the UN number; size chooses how heavily the shipment is regulated. Decide all three per SKU before anyone books a truck or a flight.

• Chemistry: rechargeable lithium ion and lithium polymer cells are "lithium ion" entries; primary, non-rechargeable cells are "lithium metal" entries (UN3090 and UN3091).
• Battery on its own: lithium ion cells or batteries shipped without the equipment they power are UN3480.
• Battery with equipment: spares in the same package as the device, or batteries installed in it, are UN3481, "packed with equipment" or "contained in equipment".
• Equipment powered only by lithium batteries: special provision 182 in 49 CFR 172.102 classifies it as UN3091 or UN3481.
• Size: watt-hours for lithium ion, grams of lithium for lithium metal, which decide whether the smaller-battery exceptions apply.

Before any of that, the cell and battery design must have passed the tests in the UN Manual of Tests and Criteria, Part III, sub-section 38.3, as 49 CFR 173.185(a)(1) requires. Under 173.185(a)(3), manufacturers and later distributors must make a test summary available. A pack with no test summary is not a classification question at all; it cannot ship as ordinary cargo until the summary exists.

Lithium ion batteries shipped alone are UN3480 and those packed with or installed in equipment are UN3481, provided each design has passed UN Manual of Tests and Criteria sub-section 38.3 under 49 CFR 173.185(a)(1); the item master should hold the test summary reference, chemistry and watt-hour rating for 100% of battery SKUs.

Watt-hour ratings and lithium content set the small-battery line

For lithium ion, the thresholds are 20 Wh per cell and 100 Wh per battery; at or below them, the 49 CFR 173.185(c) exceptions and the lighter air sections apply. Compute the rating once from the nameplate, store it, and never let a packer estimate it.

Section 173.185(c)(1)(i) sets the 20 Wh cell and 100 Wh battery limits, and (c)(1)(ii) sets 1 g per lithium metal cell and 2 g per lithium metal battery. For highway or rail only, (c)(1)(iv) raises the limits to 60 Wh per cell and 300 Wh per battery, or 5 g and 25 g of lithium metal, if the package is marked as forbidden aboard aircraft and vessel. Since 10 May 2024, (a)(5) requires each lithium ion battery's case to show its watt-hour rating.

Watt-hour rating      Wh  = V_nom x C_rated
                      Wh  = V_nom x mAh / 1000      (when capacity is in mAh)
State of charge       SoC = Q_remaining / C_rated x 100
Air test (UN3480)     SoC <= 30                     (49 CFR 172.102 A100)
Packages needed       n   = ceil( N x m_batt / M_max )

V_nom     nominal voltage of the cell or pack, volts
C_rated   rated capacity, ampere-hours (UN 38.3.2.3 method)
Q_remaining  capacity remaining when the reading is taken, Ah
N         batteries in the consignment
m_batt    net mass of one battery, kg
M_max     per-package net limit: 10 kg (PI 965 IB, cargo aircraft),
          35 kg (PI 965 IA), 5 kg (PI 966/967 Section II)

Example: 18 V x 5.0 Ah = 90 Wh per pack (5 cells of 3.6 V x 5.0 Ah = 18 Wh)
         90 Wh <= 100 Wh and 18 Wh <= 20 Wh, so smaller-battery rules apply

The example pack sits under both lines, so it qualifies for the smaller-battery treatment by ground and for Section IB by air. A 36 V, 4.0 Ah pack at 144 Wh does not: by air it moves under Section IA, and by US ground it needs the (c)(1)(iv) marking to stay within the exception, or full Class 9 treatment above 300 Wh.

UN3480 by air: freighter only, 30 percent charge, Section IA or IB

Batteries shipped on their own are the most restricted air cargo in this family. They may fly only on cargo aircraft, at a state of charge no higher than 30% of rated capacity, and always as fully declared dangerous goods.

When a US shipper uses the ICAO Technical Instructions, 49 CFR 171.24(d)(1) forbids UN3480 and UN3090 as cargo on passenger aircraft. Special provision A100 in 49 CFR 172.102 requires lithium ion cells and batteries to be offered at a state of charge not exceeding 30% of rated capacity, unless the Associate Administrator approves otherwise. IATA's 2026 battery guidance applies the same limit under packing instruction 965, with State approvals under special provision A331.

No Section II exists for PI 965, so even a small UN3480 pack moves with a Shipper's Declaration for Dangerous Goods, a Class 9 lithium battery label and a Cargo Aircraft Only label. IATA notes that the declaration's certification statement already covers the 30% requirement, so no separate state-of-charge certificate is needed; the shipper still needs its own record of how charge was checked.

UN3481 by air: batteries packed with a device versus installed in it

The equipment entries are lighter, but two limits catch shippers out: spares are limited to what the device needs plus two sets, and from 1 January 2026, batteries packed with equipment must also be at 30% charge or less when they exceed 2.7 Wh.

US rules mirror the spare-battery limit. Section 173.185(b)(3)(iii)(C) and (c)(4)(i) limit air packages to the minimum number of cells or batteries needed to power the equipment plus two spare sets, and (c)(4)(i) caps the lithium in a smaller-battery package at 5 kg net. Under (c)(4)(iii), the air waybill must show compliance with that paragraph, or with the matching ICAO packing instruction, when the package carries the lithium battery mark.

• PI 966 state of charge: IATA's 2026 guidance makes 30% mandatory for Section I and for Section II batteries above 2.7 Wh; a pack above 30% must move under Section I with State approvals.
• PI 967 state of charge: for batteries installed in equipment, 30% charge or 25% indicated capacity is strongly recommended but not mandatory.
• Small installed consignments: under PI 967 Section II, a consignment of no more than two packages, each with no more than four cells or two batteries installed, may travel without the battery mark.
• No splitting: IATA warns shippers and forwarders not to split a consignment across air waybills to stay under that two-package threshold.

Marks, labels and the passenger-aircraft warning on each carton

A compliant carton tells every handler what is inside without opening it. The lithium battery mark shows the UN number, and a separate warning or label stops the carton reaching a passenger aircraft.

• Battery mark size: 49 CFR 173.185(c)(3)(i) requires at least 100 mm by 100 mm, or 100 mm by 70 mm where the package is too small; the mark in force on 9 May 2024 may be used until 31 December 2026.
• Mark content: UN3480 or UN3090 for batteries alone, UN3481 or UN3091 for batteries with equipment; IATA asks for UN numbers at least 12 mm high.
• Passenger-aircraft warning: under (c)(1)(iii), smaller-battery packages carry "LITHIUM ION BATTERIES—FORBIDDEN FOR TRANSPORT ABOARD PASSENGER AIRCRAFT" or a Cargo Aircraft Only label, unless they hold equipment with no more than 5 kg of batteries.
• Letter height: (c)(1)(v) requires at least 6 mm on packages up to 30 kg gross and 12 mm above 30 kg, on a contrasting background.
• Overpacks: (c)(1)(vi) requires the warning or label to be visible through the overpack or repeated on its outside.
• Fully regulated packages: UN3480 by air also carries the Class 9 lithium battery label described in 49 CFR 172.447 and, under PI 965, the Cargo Aircraft Only label.

US smaller lithium ion battery packages under 49 CFR 173.185(c) need the lithium battery mark of at least 100 by 100 mm, the passenger-aircraft prohibition wording in letters of at least 6 mm, a 1.2 m drop-test capability and, when shipped alone, a gross weight no higher than 30 kg.

Moving packs by road in the US and India: what relaxes, what stays

Ground transport removes the state-of-charge limit and, for smaller batteries, most of the paperwork. It does not remove testing, short-circuit protection, the battery mark or the package weight limit.

In the US, a package meeting 173.185(c) is excepted from subparts C to H of 49 CFR Part 172, which cover shipping papers, marking, labelling, placarding, emergency response information and training, apart from what the paragraph itself requires. Packages of batteries shipped alone must stay at or below 30 kg gross under (c)(1)(vii) and survive a 1.2 m drop under (c)(2). The A100 charge limit is an air provision, so it does not bind a truck.

• Fully regulated by road: Class 9 batteries above the (c) limits still need shipping papers and labels, but 49 CFR 172.504(f)(9) does not require a Class 9 placard for domestic transportation.
• Large packs: modules above the (c) limits, including traction batteries, follow the general packaging rules in 173.185(b), and cells or batteries of 12 kg or more with a strong casing may use crates or pallets under (b)(5).
• Damaged and end-of-life packs: these follow 173.185(d) and (f), covered in our guide to lithium battery reverse logistics rather than here.

Where the Indian road rules do apply, the consignor must declare goods of a dangerous or hazardous nature on the goods forwarding note. The goods forwarding note (Form 7) and goods receipt (Form 8) prescribed by the Carriage by Road Rules, 2011 carry upper left corners printed red for such consignments, and Form 7 asks for details of the insurance cover.

Air or road for 600 tool packs: cost per shipment in dollars and rupees

The same 600 packs cost five to seven times more by air than by road once state-of-charge checks, specification boxes and DG fees are counted. Air is worth it only when the delivery date earns more than the gap.

The example uses 600 lithium ion packs of 90 Wh and 0.68 kg each. By air under PI 965 Section IB, each package may hold 10 kg net, so 14 packs (9.52 kg) fit and 43 packages are needed. By US ground under 173.185(c), 38 packs plus 2.5 kg of packaging weigh 28.34 kg, within 30 kg, so 16 cartons are enough. All rates below are illustrative assumptions.

Two costs are missing from the table because they are rare but large: a refused consignment, which pays freight twice, and a civil penalty under the inflation-adjusted maxima in 49 CFR 107.329. Both argue for building the classification into the item master rather than leaving it to the person booking freight on a deadline.

Refused at the airline counter: a power-tool pallet hour by hour

The refusal below came from a mismatch between a ground-ready pack-out and an air booking. Each document was internally consistent; none of them had been checked against the mode.

1. Fri 10:15, order released: warranty order WO-55821 for 600 spare packs is released in the ERP; the item master shows "lithium battery" but no UN number, Wh rating or state-of-charge field.
2. Fri 13:40, pack-out: the warehouse packs 16 cartons of 38 packs (25.8 kg net each) with the lithium battery mark showing UN3481, the configuration last used for tool kits by road.
3. Fri 15:05, booking: customer service upgrades to air for weekend delivery; the forwarder books general cargo on air waybill 176-48812290 from the commercial invoice, which says "batteries, spare".
4. Fri 18:20, acceptance check: the airline's acceptance agent finds UN3480 goods marked UN3481, 25.8 kg net per package against a 10 kg limit, no Class 9 or Cargo Aircraft Only labels, no declaration and no charge record; the consignment is refused.
5. Control added: battery SKUs now carry UN number, Wh rating and test summary ID in the item master, the WMS blocks an air booking on a ground pack-out, and a mode change triggers a repack task with a charge reading per pallet.

The review step at acceptance is the subject of our article on routing dangerous-goods documents to qualified air-cargo reviewers, which covers how the reviewer's decision is recorded. This article covers the decisions upstream of that desk, so that fewer consignments reach it with avoidable errors.

Classification rules to hard-stop and calls a trained person signs

Thresholds, weight limits and mode restrictions are fixed numbers, so the WMS or shipping system should enforce them. Signing the declaration and judging an unusual product remain with a trained person.

Lithium battery air bookings from a WMS should hard-stop any UN3480 consignment lacking a state-of-charge reading at or below 30% under 49 CFR 172.102 special provision A100, or exceeding the 10 kg PI 965 Section IB package limit, before the forwarder issues an air waybill.

Dispatch and yard checklist before a battery consignment leaves

Most refusals and penalties trace back to a missing master-data field or a mode change after packing. A short checklist run at release, at pack-out and at the dock catches both.

Stacking, segregation and tunnel restrictions for mixed dangerous goods loads are handled in our multimodal DG load check guide; the list below is limited to the battery-specific gates for a single consignment.

Lithium batteries connect to several other topics in our logistics and supply chain library, from returns to dangerous goods load planning. If you want battery classification rules built into your item master, WMS and booking flow, you can describe your SKUs, lanes and carriers through our request for proposal form.