Compared to many other battery chemistries, lithium-Ion batteries have higher power density, lower memory effect, and last longer. However, they remain sensitive to a variety of factors including heat, overcharging, discharging, damage, and short-circuiting. If stressed, lithium-ion batteries can explode, cause damage, hurt someone, or worse. For this reason, batteries are considered “dangerous goods” and are subject to a variety of transportation regulations.
If you’ve ever ordered batteries online or had to travel with your personal electronics, you have probably been exposed to these regulations to some degree.
Here’s a quick guide to explain these regulations for the next time you need to import Li-ion batteries or fly with them. Of course, always double check with your shipper or airline to make sure you are aware of the latest rules.
UN/DOT 38.3 Test
For all lithium-ion batteries, the manufacturer is responsible for assuring their batteries past the DOT 38.3 test, which was developed by the United Nations. The DOT 38.3 test covers the following:
- T1 – Altitude simulation: This simulates the cargo environment of an aircraft at an altitude of 50,000 feet and 11.6 kPa for six hours or longer without damage and with less than 10% of voltage lost.
- T2 – Thermal test: Batteries must sustain ten cycles of storage at -40F and 167F for six hours at each temperature.
- T3 – Vibration: The vibration tests simulates worst-case conditions for transport and involve a sine sweep of 7Hz-200Hz-7Hz over a period of 15 minutes. The batteries must sustain 12 sweeps total over a period of three hours.
- T4 – Shock: Batteries must pass a shock test of 50G/6ms (small batteries) and 50G/11ms (large batteries). Batteries are subjected to three pulses in the x, y, and z plane in both directions.
- T5 – External short circuit: A short circuit of less than 0.01ohm is applied at 131F. The short circuit may not generate a temperature exceeding 338F and batteries must return to original temperature within an hour.
- T6 – Impact: For primary and secondary cells, batteries larger than 20mm in diameter are tested for impact. Batteries less than 20mm in diameter or tested for crushing.
- T7 – Overcharge: For rechargeable batteries, they are charged at a charge current twice the manufacturer's recommendation over a period of 24 hours, then monitored for seven days.
- T8 – Forced discharge: For primary and secondary cells, the batteries are forced discharged and monitored for seven days.
United States Postal Service (USPS): Ground Shipping
Regulations for shipping batteries by post are managed by the US Department of Transportation (DOT) and the Pipeline and Hazardous Materials Safety Administration (PHMSA).
A maximum of four cells or two batteries (in equipment) is permitted to be shipped without a label.
Above this quantity (more than two batteries, or more than eight cells), a special shipping label must be included. The typical label is at minimum 110x120mm in dimensions, bordered with red, diagonal hatchings, with battery symbols in black and on a white background. Instructions on transport method in the event the batteries must be returned to sender must be included, as well as the UN number, which describes the battery chemistry. For lithium-ion batteries, this is UN 3480 and UN 3481 (batteries packed within equipment). A phone number for someone knowledgeable about the batteries being transported must be included as well. This label must include a warning about potential flammability if the package is damaged.
A typical battery shipping label. Image courtesy of IATA.
When single batteries are shipped alone (not in equipment), the label must include “Surface Mail Only, Lithium Metal Batteries — Forbidden for Transportation Aboard Passenger Aircraft”.
When shipping internationally, lithium-ion batteries may only be shipped in the equipment they will power—for example, inside a mobile phone.
By Courier (FedEx, UPS)
Generally, couriers will follow the same air or ground shipment rules, with the exception for express shipment. In order to express ship lithium-ion batteries, a request must be submitted in advance and approved, with a dangerous goods shipment contract. A form will usually be filled out with various details on the shipment.
International Air Transport Association (IATA): Shipping by Air
In the IATA’s 2017 Lithium Ion Battery Guidance Document, there are three configurations in which batteries are transported:
i) Contained within equipment
ii) Packed with, but not contained in, equipment
iii) Packed by themselves
Lithium ion batteries are also categorized as “lithium ion” or “lithium metal”.
Lithium ion/metal batteries are not permitted to be shipped onboard a passenger airplane as cargo, and must be shipped on separate cargo flights at a state of charge of 30% with packaging that reads “For Cargo Aircraft Only”. When packaging batteries for air transport, they must be done so in a way where none of their terminals may come in contact (where they can potential short-circuit) and are protected from potential damage. Encasing the terminals and using reinforced packaging is recommended.
Shipping batteries within equipment (for example, a laptop battery compartment) is generally sufficient to keep them protected as long as they can not be accidentally activated. Packages must be capable of sustaining a drop from a height of approximately four feet without damage, and the packaging must have a lithium battery shipping label (as described above). The maximum weight of a package containing lithium batteries may not exceed 35 kg.
Batteries which have known defects (such as in the case of a recall) are not permitted to be shipped by air.
Traveling with Lithium Ion Batteries
Batteries being brought onboard an aircraft by passengers are also subject to some rules.
For batteries not contained within an electronic device (“spares”):
- Batteries must be transported with the passenger in their carry-on luggage, not in checked luggage, and must be protected from short circuiting
- The batteries may not exceed 100 Wh per battery, or with approval, 160 Wh (in which case there is a maximum of two batteries)
- Recalled batteries may not be brought onboard an aircraft
Electronics which contain lithium-ion batteries are permitted for travel, and may also be transported in checked luggage.
Image courtesy of the European Aviation Safety Agency.