UN38.3 Battery Transport Requirements

UN38.3 is the United Nations test standard for lithium batteries in transport. For EV importers, this determines the documentation required to ship a vehicle with a traction battery via sea freight.

When UN38.3 applies

UN38.3 applies to lithium batteries being transported. For EVs, this includes the traction battery (the main drive battery) and 12V auxiliary batteries that use lithium chemistry.

Most passenger EVs (Nissan Leaf, Tesla Model 3, Mitsubishi i-MiEV) and kei EVs (Mitsubishi Minicab MiEV) fall under this requirement.

Container vs RoRo treatment

RoRo (Roll-on/Roll-off) shipping: Most major car carriers transport EVs on RoRo vessels with the battery installed in the vehicle, under specific protocols. The vehicle manufacturer’s IMDG (International Maritime Dangerous Goods) declaration for the vehicle model typically satisfies RoRo requirements.

Container shipping: When shipping in a container, IATA/IMDG dangerous goods regulations apply more stringently. A UN38.3 test summary report for the specific battery model is required by many carriers. Your freight forwarder coordinates this.

Getting the documentation

Vehicle manufacturers publish UN38.3 test summaries for their battery packs. For Japanese domestic market vehicles (Nissan, Mitsubishi, Toyota), this documentation is available from the manufacturer upon request, or through specialist EV import agents in Japan.

WATTSHIP’s Trade Vault (CC Trader+) stores UN38.3 certificates alongside other compliance documents for your shipments.

State of charge requirements

Most carriers require EV batteries to be transported at 20-30% state of charge. Driving the vehicle onto an RoRo vessel at 100% SOC may trigger a carrier refusal. Your export agent in Japan handles this.

Radiation documentation (post-Fukushima)

For vehicles from prefectures near the 2011 exclusion zone, radiation measurement certificates are now standard port practice at most Japanese export ports. Vehicles pass through radiation monitors at port — certificates are issued automatically for compliant vehicles.