Code reference

What is UN3480?

UN3480 is the identification number for lithium ion cells and batteries shipped on their own, with nothing else in the package. Its partner UN3481 covers the identical chemistry when the battery rides inside or packed with the equipment it powers, and the non-rechargeable lithium metal family uses UN3090 and UN3091 the same way. Federal rules hold an excepted lithium ion cell to 20 watt-hours, a battery to 100 watt-hours, and the whole package to 30 kg gross.

Four UN numbers separatedThresholds quoted from 49 CFRMark dimensions given
A hatched lithium battery mark printed beside an address label
A number, not a brand

The mark is standard worldwide. The number printed inside it is the part that has to match what is in your box.

Four numbers, one decision

Two questions settle which code applies: what chemistry the cell uses, and whether it travels with its equipment.

Lithium UN numbers and the excepted-shipment ceilings that go with them, from 49 CFR 173.185 in the 2024 Code of Federal Regulations via govinfo.gov, read 2026-07-28.
UN numberWhat it coversEveryday examplesExcepted ceiling
UN3480Lithium ion cells and batteries shipped by themselvesPower bank, spare tool pack, replacement phone battery20 Wh per cell, 100 Wh per battery
UN3481Lithium ion batteries contained in, or packed with, equipmentPhone, laptop, camera, drone, cordless drillSame watt-hour ceilings, with equipment packing rules
UN3090Lithium metal cells and batteries shipped by themselvesNon-rechargeable camera and watch cells1 g lithium per cell, 2 g per battery
UN3091Lithium metal batteries contained in, or packed with, equipmentDevices running on primary lithium cellsSame gram limits, with equipment packing rules
The Watt-hour (Wh) rating may not exceed 20 Wh for a lithium ion cell or 100 Wh for a lithium ion battery. After December 31, 2015, each lithium ion battery subject to this provision must be marked with the Watt-hour rating on the outside case.49 CFR 173.185(c)(1)(i), govinfo.gov, read 2026-07-28

That printed rating on the case is what makes this checkable at home. A laptop pack marked 56 Wh sits comfortably inside the ceiling; an electric bike pack marked 500 Wh does not, and no self-service checkout can carry it.

Package limits and the mark itself

The exception that lets ordinary lithium shipments move without full dangerous goods paperwork comes with numbers attached, and they are specific.

Except when lithium cells or batteries are packed with, or contained in, equipment, each package must not exceed 30 kg (66 pounds) gross weight.49 CFR 173.185(c)(1)(vii), govinfo.gov, read 2026-07-28
The mark must be in the form of a rectangle or a square with hatched edging. The mark must be not less than 100 mm (3.9 inches) wide by 100 mm (3.9 inches) high, and the minimum width of the hatching must be 5 mm (0.2 inches), except marks of 100 mm (3.9 inches) wide by 70 mm (2.8 inches) high may be used on a package containing lithium batteries when the package is too small for the larger mark.49 CFR 173.185(c)(3)(i)(A), govinfo.gov, read 2026-07-28

The symbols and letters are black on white or another contrasting background and the hatching is red, with the asterisk on the printed mark replaced by the UN number that applies. Packages are also required to survive a 1.2 meter drop in any orientation without the cells shifting into contact or the contents escaping, which is the real argument for a rigid inner box rather than a padded envelope.

One exemption is worth knowing: the mark is not required when a package holds only button cells installed in equipment, or when a consignment is two packages or fewer and each holds no more than four cells or two batteries contained in equipment.

The ground-only uprate, and what shipping costs

There is a second tier most guides never mention, and it exists precisely because road transport tolerates more than aircraft do.

For transportation by highway or rail only, the lithium content of the cell and battery may be increased to 5 g for a lithium metal cell or 25 g for a lithium metal battery and 60 Wh for a lithium ion cell or 300 Wh for a lithium ion battery, provided the outer package is marked: LITHIUM BATTERIES-FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL.49 CFR 173.185(c)(1)(iv), govinfo.gov, read 2026-07-28

A 300 Wh ceiling on the road against 100 Wh in the air is a threefold difference, and it explains why so many battery shipments quote with ground services only. The trade is a stricter marking and no aircraft, ever.

Five live services for a 12 x 10 x 6 in box at 5 lb, Newark, NJ 07102 to Los Angeles, CA 90011, quoted 2026-07-28. A cross-country ground lane of the sort battery shipments are held to.
CarrierServicePriceTransit window returned
UPSGround Saver$19.14Not returned for this row
UPSGround$19.306-7 business days
USPSGround Advantage$19.645-6 business days
FedExGround Economy$20.507-8 business days
UPS2nd Day Air$31.432-3 business days

The air row at the bottom is there because that quote carried no battery. Declare a power bank and the list that returns holds ground services alone, which is the enforcement working rather than a shortage of options.

Alone or installed changes everything

A battery inside the device it powers is protected by that device and is treated more gently by the rules, which is why UN3481 shipments face fewer conditions than UN3480 ones. Fitting a spare pack into the tool before boxing it is a legitimate way to change which code applies.

Watt-hours, not milliamp-hours

Consumer packaging advertises mAh, while the regulation works in watt-hours. Multiply amp-hours by the nominal voltage to convert: a 10,000 mAh pack at 3.7 volts is 37 Wh, comfortably under the 100 Wh line.

Damaged cells have no lane at all

Swollen, leaking, recalled or fire-damaged batteries are outside every exception described here. No UN number, mark or service makes them shippable through a self-service checkout, ours included, and our restrictions policy says so directly.

UN3480 questions

What does UN3480 mean?

It identifies lithium ion cells and batteries shipped on their own, without equipment in the package. Power banks, spare tool packs and replacement phone batteries all ship under that number.

What is the difference between UN3480 and UN3481?

The equipment. UN3481 covers lithium ion batteries contained in, or packed with, the equipment they power, while UN3480 is for batteries travelling alone. The lithium metal equivalents are UN3090 and UN3091.

What are the watt-hour limits?

For excepted shipments, 20 Wh for a lithium ion cell and 100 Wh for a lithium ion battery, per 49 CFR 173.185(c)(1)(i). Highway and rail transport allows 60 Wh per cell and 300 Wh per battery with a stricter marking on the box.

How large must the lithium battery mark be?

Not less than 100 mm wide by 100 mm high, with hatching at least 5 mm wide. A reduced mark of 100 mm by 70 mm is allowed when the package is too small for the full size.

Price a tool with a battery Where the mark goes

Related references

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