If you're importing or exporting lithium batteries, one thing has changed for 2026 and it's easy to miss: the 30% state-of-charge (SoC) limit is no longer a recommendation — it's now a hard requirement for shipping standalone lithium-ion cells and batteries by air. Get this wrong and your shipment gets rejected at the terminal. This guide walks through the documents and numbers that keep a battery shipment moving.
1. The Document That's Non-Negotiable: UN38.3 Test Summary
You cannot legally ship a lithium battery without a valid UN38.3 test summary. It proves the battery passed a set of transport-safety tests. Two things to check carefully:
- It must match the exact battery model, capacity and configuration you're shipping — a summary for a 3,000mAh pack doesn't cover the 5,000mAh version.
- Carriers and customs cross-check the test summary against your commercial documents, so a mismatch means delays.
2. The 30% State-of-Charge Rule (Now Mandatory)
Starting January 2026, the 30% max charge is a strict legal requirement, not a guideline:
| What's shipping | UN number | Requirement |
|---|---|---|
| Standalone lithium-ion cells/batteries | UN3480 (PI965) | 30% max SoC |
| Batteries packed with equipment | UN3481 (PI966) | 30% max SoC (over 2.7Wh) |
| EVs / battery-powered vehicles | UN3556 (PI952) | 30% max SoC (over 100Wh) |
If a battery ships above 30% charge, an airline can refuse it outright. This is why manufacturers now discharge packs to a storage state before export — and it's a legitimate question to ask your supplier: "do you ship at ≤30% SoC and provide the UN38.3 summary?"
3. The Other Certifications Buyers Actually Ask For
- MSDS / SDS — material safety data sheet for chemical composition and handling. Carriers and customs ask for it routinely.
- CE — required for the European market.
- ISO9001 — quality management system, increasingly expected by B2B buyers.
- Target-market certs — UL for North America, and others depending on destination. A good supplier helps you get these for your market.
4. Air vs. Sea: The Rules Differ
Air has the strictest limits (the 30% SoC rule, specific UN numbers, UN38.3 mandatory). Sea follows the IMDG code — also requires UN38.3 and proper packaging, but the SoC rules are generally more flexible. For large energy-storage systems, sea freight is almost always the practical route, and the dangerous-goods declaration becomes critical.
5. A Checklist for Every Import/Export Order
- ☐ UN38.3 test summary matching the exact model you're shipping
- ☐ Correct UN number (3480/3481/3556…) on documents and packaging
- ☐ Discharged to ≤30% SoC (for air and when required)
- ☐ MSDS/SDS included with the shipment
- ☐ CE / target-market certifications in place
- ☐ Dangerous-goods declaration for sea freight
- ☐ Packaging that meets the carrier's marking and labeling rules
Rule of thumb for buyers: any serious lithium-battery supplier should be able to hand you the UN38.3 summary, confirm 30% SoC shipping, and explain the certification path for your country. If they can't, that's a red flag — not a detail to wave off.
Shipping lithium batteries doesn't have to be scary, but it is unforgiving about paperwork. Nail the UN38.3 summary and the 30% rule, and you've already avoided the two most common reasons shipments get stuck.
Frequently Asked Questions
What documents are required to ship lithium batteries internationally?
The core set is UN38.3 test report, MSDS/SDS, and a transport certificate; air shipments also need the lithium battery handling label and proper packaging per IATA DGR. Sea freight follows IMDG rules with comparable documentation.
What is UN38.3 and why does it matter?
UN38.3 is the UN transport test standard for lithium cells and batteries (altitude, thermal, vibration, shock, short-circuit, impact and overcharge tests). Without a passing UN38.3 report, air carriers will refuse the shipment.
Can lithium batteries ship by air or sea?
Both are possible under rules: smaller cells/batteries ship by air within the IATA watt-hour and package limits (often with restrictions), and larger packs typically go by sea. Your freight forwarder or the manufacturer confirms the right mode per battery size.
How should lithium batteries be packaged for transport?
Cells must be protected against short circuit (terminals insulated), packed in strong outer packaging, and the package marked with the lithium battery handling label. Damaged or recalled cells are forbidden from transport.