Shipping Lithium Battery by Sea from China: IMDG Code 42-24 (2026)
Last updated: June 26, 2026 · Reading time: 18 minutes · Author: Bill Guo, Sales Manager, BAT Logistics
From the BAT desk: Sea is the mode we use most for battery freight — about 70% of our 6,500+ battery shipments have gone by sea. The rules are different from air (no SoC 30% requirement, but the UN classification, packaging, and documentation are stricter in their own way). IMDG Code 42-24 became mandatory January 1, 2026, and it brought a wave of changes — new UN numbers for sodium-ion, new rules for electric vehicles, and tighter enforcement at every major port. This guide is what we wish every first-time sea battery shipper had read before their first container left Yantian.
Table of Contents
Quick Answer (Featured Snippet)
Need to ship lithium batteries by sea from China in 2026? Five things you absolutely have to get right:
- IMDG Code Amendment 42-24 is mandatory from January 1, 2026. Every sea battery shipment out of China must follow the new edition. The biggest changes: UN3551/3552 for sodium-ion, UN3556-3558 for battery-powered vehicles, and tighter enforcement at major Chinese ports (Shenzhen, Ningbo, Shanghai).
- The right UN classification is the foundation. UN3480 (battery alone) vs UN3481 (battery packed with or in equipment) — a one-digit difference that changes everything: packing instruction, documentation, stowage category, carrier acceptance.
- A reefer container set to 15-25°C is the safe default. Not because the battery needs to be cold, but because temperature stability prevents SoC drift and keeps the cells well below the thermal runaway threshold (typically 45-60°C for Li-ion).
- The 6 core documents are: UN38.3 Test Report, MSDS/SDS, IMO Dangerous Goods Declaration, Class 9 Hazard Label, Lithium Battery Handling Mark, plus the Marine Transport Test Report (a China-specific document).
- Real numbers for 2026: $1,800-3,500 per 40HQ reefer container FCL; $90-140/CBM for DDP; transit 15-35 days depending on destination. Sea is 60-80% cheaper than air for shipments over 500kg, but 10-20x slower.
Master these five, and you’ll avoid the 8 common mistakes that get sea battery shipments rejected at port (we cover all 8 in section 10).
June 2026 Sea Battery Update (IMDG 42-24 )
Three things changed in the IMDG Code 42-24 amendment that every sea battery shipper needs to know:
1. Sodium-ion batteries now have official UN numbers. UN3551 covers standalone sodium-ion batteries (cells, modules, packs with organic electrolytes). UN3552 covers sodium-ion batteries contained in or packed with equipment. CATL and BYD are shipping commercial volumes in 2026. If your product spec changed from lithium to sodium, the UN number changes — the carrier will reject it if you declare the wrong one.
2. Battery-powered vehicles got their own UN numbers. UN3556 for Li-ion powered vehicles, UN3557 for Li-metal, UN3558 for sodium-ion. The old catch-all UN3171 is being phased out for these categories. If you’re shipping e-bikes, e-scooters, or small EVs as complete units, you need the right UN number or the booking won’t go through.
3. Class 9 labeling and ISO 17363 transport documents are now strictly enforced. Major forwarders (DHL Global Forwarding, Kuehne+Nagel, Maersk) have implemented active rejection policies for shipments missing compliant labels or transport documents. Shenzhen and Ningbo ports have publicly reported multiple container rejections in Q1 2026. The transition period that allowed Amendment 41-22 ran throughout 2025; in 2026, only 42-24 is accepted.
The practical impact: any sea battery shipment booked in 2026 needs a fresh Marine Transport Test Report aligned with 42-24, the correct 2026 UN number, and reefer setup for any shipment over 500kg or traveling through tropical waters.
1. 4 Sea Freight Service Types (FCL / LCL / Reefer / DDP)
FCL (Full Container Load)
Most CommonYour goods occupy the entire container (20ft/40ft/40HQ). Max volumetric efficiency with minimal touchpoints.
- Best for shipments > 15 CBM
- 15-20% cheaper per CBM than LCL
- Class 9 DG accepted on most routings
- Isolated customs risk (No co-loader delays)
LCL (Less than Container Load)
For Small BatchesShared container space consolidated at origin CFS. Ideal for smaller volumes or sample validation.
- Best for cargo under 15 CBM
- Flexible budgeting for test batches
- ⚠️ Note: Strict CFS warehouse acceptance
- ⚠️ Risk: Co-loader compliance may affect transit
Reefer (Temperature Controlled)
Highly RecommendedActive temperature control set to 15-25°C. Crucial for preventing SoC drift and ensuring stability.
- Mandatory for battery cargo > 500kg
- Prevents extreme tropical port heat (50°C+)
- Full data logger temperature tracking
- Premium protection against thermal runway
DDP (Delivered Duty Paid)
Seamless Door-to-DoorAll-inclusive solution covering ocean freight, export/import clearance, destination duties, and final mile delivery.
- Zero destination broker required
- Fixed transparent landed cost upfront
- Hassle-free customs & tax handling
- Perfect for first-time importers
Choosing the right sea service is half the cost question, half the compliance question. Here’s how the 4 options differ for battery freight.
FCL (Full Container Load) — Most Common for Battery
Your goods are the only cargo in the container. Standard sizes: 20ft (28-30 CBM), 40ft (58-60 CBM), 40HQ (68-70 CBM). For battery freight, 40HQ is the most common because of the volumetric efficiency.
- Best for: shipments over 15 CBM, large e-bike batches, BESS modules, EV battery packs
- Cost advantage: 15-20% cheaper per CBM than LCL
- Handling: your cargo is only loaded/unloaded at origin and destination — far fewer touch points
- DG acceptance: Class 9 dangerous goods are accepted on most FCL routings (with carrier pre-approval)
- Customs risk: if your container is selected for inspection, only your cargo is examined — no other shipper’s problems can delay you
LCL (Less than Container Load) — For Small Batches
Your goods share a container with other shippers’ cargo. Consolidated at a CFS (Container Freight Station) at origin, de-consolidated at destination CFS.
- Best for: shipments under 15 CBM, samples, small e-commerce orders
- Cost disadvantage: 30-50% more per CBM than FCL
- Handling risk: cargo is handled at origin CFS, consolidated with other goods, de-consolidated at destination CFS — each touch point is a damage opportunity
- DG acceptance: not all warehouses accept Class 9 battery cargo for LCL consolidation. Many CFS facilities will refuse your cargo outright.
- Customs risk: if another shipper’s goods in the same container have an issue (customs hold, contamination, mis-declaration), your cargo can be delayed or quarantined
Real example: A client of ours shipped 8 CBM of e-bike batteries from Shenzhen to Hamburg via LCL. Another shipper in the same container had undeclared perfume (Class 3 flammable liquid). Customs held the entire container for 3 weeks. The e-bike batteries survived, but the client missed their Q1 retail deadline and ate USD 4,200 in extra demurrage and re-routing costs.
Reefer (Refrigerated Container) — Recommended for All Battery
A reefer container with active temperature control. For battery freight, set to 15-25°C (not below 0°C — batteries don’t need to be cold, they need temperature stability).
- Best for: any battery shipment over 500kg, any shipment through tropical waters, any shipment with SoC > 30% (yes, sea doesn’t have the SoC rule, but a stable temperature is still your friend)
- Cost: USD 400-800 reefer surcharge per container, on top of FCL ocean freight
- Temperature monitoring: all reefers have data loggers; you can pull the temperature record at destination
- The why: lithium batteries in a tropical port can hit 50-60°C in a dry container. That’s thermal runaway territory. A reefer holds the temperature at a level that keeps the cells well within safe operating range
The “do I really need a reefer?” question: for shipments under 200kg going to temperate destinations (Northern Europe in winter, US Pacific Northwest year-round), you can get away with a dry container. For everything else, we strongly recommend reefer. The USD 400-800 surcharge is cheap insurance against a thermal event.
DDP (Delivered Duty Paid) Door-to-Door — Easiest for First-Timers
One price covers everything: ocean freight, customs duties, VAT/GST, and final delivery to the consignee’s door. $90-140 per CBM by sea, 10-15 days longer than DDU typically.
- Best for: first-time shippers, anyone who doesn’t have a destination broker
- What we handle: ocean freight, export customs, import customs, duty/VAT payment, last-mile delivery
- What you handle: origin pickup (or we handle that too), accurate commercial invoice, accurate HS code
- The catch: DDP requires accurate HS codes and product values upfront. If you under-declare the value, you might save on duty but face penalties later. If you over-declare, you pay more duty than needed.
The decision rule:
Your shipment | Best service |
|---|---|
< 5 CBM, sample size | LCL or DHL/FedEx |
5-15 CBM, small batch | LCL (if warehouse accepts DG) or FCL if speed matters |
15-30 CBM, regular batch | FCL reefer (most common) |
30+ CBM, large batch | FCL reefer or multiple containers |
First time, no destination broker | DDP |
Tropical route or summer | FCL reefer (no exceptions) |
2. UN Classification Deep Dive (7 Numbers You Need to Know)
Bulk / Standalone
UN 3480
Lithium-Ion Batteries
The workhorse for bulk battery shipments. Power banks, e-bike battery packs, and BESS modules shipped alone without equipment.
- Class: 9 (Dangerous Goods)
- Packing Group: II (Medium Danger)
- Packing Instruction: P903
- Stowage: Category A (On/Under deck)
With Equipment
UN 3481
Li-Ion Packed / Contained
Batteries contained inside devices (e.g., laptops, smartphones) or packed together with the equipment in the same outer box.
- Class: 9 (Dangerous Goods)
- Packing Instruction: P905 / P906
- SP 188 Eligible: If < 100Wh per battery
- Lighter packaging rules apply
2026 New Standard
UN 3551
Sodium-Ion Batteries
Covers standalone sodium-ion cells, modules, and battery packs with organic electrolytes (e.g., CATL/BYD commercial volumes).
- Mandatory: Effective Jan 1, 2026
- Class: 9 (Dangerous Goods)
- Packing Instruction: P903 provisions
- Strictly checked at Shenzhen/Ningbo
With Equipment
UN 3552
Sodium-Ion In/With Equipment
The sodium-ion equivalent of UN3481. Applies to sodium-ion batteries installed in or packed with scooters or devices.
- Class: 9 (Dangerous Goods)
- Packing Instruction: P905 / P906
- Requires specific 2026 MSDS update
- Different handling mark declarations
Vehicle Split
UN 3556
Li-Ion Powered Vehicles
New classification for complete e-bikes, e-scooters, and small EVs driven by lithium-ion batteries. Phasing out the old UN3171.
- Scope: Complete vehicle units
- Packing Instruction: P905
- Carrier pre-approval required
- Active rejection policy if misdeclared
Primary / Non-Rechargeable
UN 3090
Lithium Metal Batteries
Non-rechargeable primary cells (e.g., bulk watch batteries, military gear, medical devices). Highly sensitive to heat.
- Class: 9 (Dangerous Goods)
- Limits: 1g per cell / 2g per battery
- Packing Instruction: P904
- Stricter carrier stowage rules
With Equipment
UN 3091
Li-Metal In/With Equipment
Lithium metal batteries contained inside or packed with equipment (e.g., smoke detectors, tracking sensors with primary cells).
- Class: 9 (Dangerous Goods)
- Packing Instruction: P905 / P906
- Subject to aggregate lithium limits
- Requires standard Class 9 DG labeling
Every sea battery shipment starts with the right UN number. Get this wrong and the booking is rejected before it begins. The 7 numbers you need to know for sea battery freight:
UN3480 — Lithium-Ion Batteries (Standalone)
The workhorse for bulk battery shipments. Power banks, e-bike batteries, BESS modules, EV battery packs — all by themselves, not in any device. Packing Instruction P903.
- Class: 9 (Miscellaneous Dangerous Goods)
- Packing Group: II (medium danger)
- Packing Instruction: P903
- Label: Class 9 diamond + Lithium Battery Handling Mark
- Stowage: Category A (on deck or under deck, away from heat sources)
UN3481 — Lithium-Ion Batteries (Packed With or Contained In Equipment)
The battery is in the same outer package as equipment (packed with) or installed in equipment (contained in). Packing Instructions P905 (contained in equipment) or P906 (packed with equipment).
- Class: 9
- Packing Group: II
- Packing Instruction: P905 or P906
- Label: Class 9 + Lithium Battery Handling Mark
- Stowage: Category A
UN3090 — Lithium Metal Batteries (Standalone)
Non-rechargeable primary cells: watch batteries, hearing aid batteries, some medical device batteries. More strictly regulated than lithium-ion. Packing Instruction P904.
- Class: 9
- Packing Group: II
- Packing Instruction: P904
- Lithium content limits: 1g per cell, 2g per battery
- Label: Class 9 + Lithium Battery Handling Mark
UN3091 — Lithium Metal Batteries (Packed With or Contained In Equipment)
Same lithium content limits, but in or with equipment. Less common than UN3090.
UN3551 — Sodium-Ion Batteries (Standalone) — 2026 NEW
The new UN number for sodium-ion standalone batteries. Applies to sodium-ion cells, modules, and battery packs with organic electrolytes. Packing Instruction P903 (similar to UN3480).
- Class: 9
- Packing Group: II
- Packing Instruction: P903 (with sodium-ion specific provisions)
- Label: Class 9 + Lithium Battery Handling Mark (sodium-ion included in 2024 update)
- 2026 enforcement: major ports are actively checking for the correct UN number
UN3552 — Sodium-Ion Batteries (Contained in or Packed with Equipment) — 2026 NEW
The sodium-ion equivalent of UN3481. Same Class 9 designation, same Class 9 labeling, slightly different documentation requirements.
UN3556 / UN3557 / UN3558 — Battery-Powered Vehicles — 2026 NEW
The 2024 amendment split out the legacy UN3171 catch-all for battery-powered vehicles:
- UN3556 — Lithium-ion battery powered vehicles
- UN3557 — Lithium-metal battery powered vehicles
- UN3558 — Sodium-ion battery powered vehicles (under SP 404, exempt from IMDG if battery is short-circuited with no electrical energy)
If you ship complete e-bikes, e-scooters, or small EVs, you need the right one of these three.
Quick UN Selection Cheat Sheet
Scenario | UN # | PI |
|---|---|---|
Bulk power bank in boxes | UN3480 | P903 |
Power bank in retail box with cable | UN3481 | P906 |
Phone with battery installed | UN3481 | P905 |
E-bike battery alone (pack, no bike) | UN3480 | P903 |
E-bike as complete unit (battery installed) | UN3556 | P905 |
Bulk sodium-ion battery pack | UN3551 | P903 |
Sodium-ion battery in scooter | UN3552 | P905 |
Bulk watch batteries | UN3090 | P904 |
Smoke detector with Li-metal cell | UN3091 | P905 |
Damaged/defective battery (any chemistry) | Same UN + SP 376 | P910 |
3. P903-P911 Packing Instructions (7 PI Every Sea Shipper Should Know)
Packing Instructions are the “how to package” rules for each UN number. Here’s the sea battery PIs you need to know:
P903 — Lithium-Ion Standalone (UN3480)
The most common PI for sea battery freight. Requirements:
- Packaging performance level: Packing Group II (medium danger, passes 1.2m drop test, 100kPa stacking test)
- Inner packaging: each cell or battery in a non-conductive inner package (plastic bag, foam pocket, individual compartment)
- Short circuit prevention: terminals protected, no contact with conductive materials in the same package
- Outer packaging: strong rigid outer (fiberboard, plastic, metal) meeting 4.1.1.1, 4.1.1.2, 4.1.1.5 IMDG requirements
- Weight limit: 30kg max net weight per package for sea (35kg for air under PI 965)
- Marking: UN number, proper shipping name, Class 9 label, Lithium Battery Handling Mark
P904 — Lithium Metal Standalone (UN3090)
Similar to P903 but with stricter lithium content limits: 1g per cell, 2g per battery. Inner packaging must prevent short circuit; outer must be rigid.
P905 / P906 — Lithium Batteries in/with Equipment (UN3481)
- P905 = contained in equipment (battery installed)
- P906 = packed with equipment (battery separate from equipment but in same outer)
Lighter packaging requirements than P903 because the equipment provides some inherent safety. Class 9 label still required if battery exceeds certain thresholds.
P908 / P909 — Damaged/Defective Batteries (Non-SP376 cases)
For batteries that have minor damage or defects but don’t meet the SP 376 criteria for full P910 treatment. Stricter packaging: individually packed, surrounded by non-combustible thermal insulation.
P910 — Damaged/Defective Batteries Under SP 376
The most stringent PI for sea battery freight. Required for batteries that:
- Show signs of damage (swelling, denting, leakage)
- Have been identified as defective by the manufacturer
- Cannot pass UN38.3 testing
Packaging requirements:
- Each cell/battery individually packed in inner packaging, placed in outer packaging
- Inner pack surrounded by sufficient non-combustible, electrically non-conductive thermal insulation material
- Cells/batteries with net mass exceeding 30kg: limited to one per outer packaging
- Outer packaging must be UN-certified, Packing Group I performance level
- Special marking: “DAMAGED/DEFECTIVE LITHIUM BATTERIES” in 12mm font
- Carrier pre-approval mandatory (this is the most expensive, most paperwork-heavy scenario)
- Cost: 3-5x normal battery shipping
P911 — Lithium Batteries for Recycling/Disposal
For end-of-life batteries being shipped to a recycling facility. Different documentation requirements (waste shipment documentation), but packaging is similar to P903.
Which PI Do I Need?
Your scenario | UN # | PI |
|---|---|---|
Bulk battery, no defects | UN3480 | P903 |
Battery in working device | UN3481 | P905 |
Battery + device, not installed | UN3481 | P906 |
Damaged or swollen battery | Same UN | P910 + SP 376 |
End-of-life battery for recycling | Same UN | P911 |
4.SP 188 Exemption — When You Don't Need Full DG
Special Provision 188 is the IMDG equivalent of air’s “Section II” exemption. If your batteries meet these criteria, you skip the full dangerous goods treatment.
The Thresholds
For SP 188 to apply, your cells/batteries must meet all of the following:
- Lithium-ion / sodium-ion cells: watt-hour rating not more than 20Wh
- Lithium-ion / sodium-ion batteries: watt-hour rating not more than 100Wh
- Lithium metal cells: lithium content not more than 1g
- Lithium metal batteries: aggregate lithium content not more than 2g
- UN38.3 tested: the cell or battery type has passed the 8 UN38.3 tests
- Short circuit protection: terminals protected, no risk of short circuit during transport
- Strong outer packaging: meets general packaging requirements of 4.1.1.1, 4.1.1.2, 4.1.1.5
What You Get If You Qualify
- ✅ No full Dangerous Goods Declaration (DGD)
- ✅ No IMO shipper’s declaration
- ✅ No Class 9 hazard label required (Lithium Battery Handling Mark still required)
- ✅ No special stowage category
- ✅ No carrier DG pre-approval
This makes SP 188 shipments significantly cheaper and faster to book. Common scenarios:
- Small consumer electronics (phone batteries, laptop batteries) shipped in retail packaging
- Small power banks under 100Wh shipped in retail packaging
- IoT device batteries shipped inside the device
- Small drone batteries under 100Wh
What You Don’t Get
You still need:
- UN38.3 test report (current, model-matching)
- MSDS
- Commercial invoice + packing list
- Lithium Battery Handling Mark on each package
- A statement on the transport document: “Transport in accordance with special provision 188”
The Lithium Battery Handling Mark replaces the Class 9 label for SP 188 shipments. It looks like a rectangular label with the battery symbol, “Lithium batteries” text, and handling instructions.
5. Reefer Container Setup (15-25°C + Temperature Monitoring)
This is the part of sea battery freight that most new shippers underestimate. The reefer isn’t there to keep the battery cold — it’s there to keep the temperature stable within a safe range.
Why Temperature Matters for Lithium Batteries
Lithium-ion batteries have a thermal runaway threshold. For most Li-ion chemistries, that’s around 45-60°C. Above that threshold, the cell’s self-heating exceeds its ability to dissipate heat, and a chain reaction starts that ends in fire or explosion.
Three things happen to a battery in a hot container:
- SoC drift: higher temperatures cause the cell’s voltage to drift upward, simulating a higher state of charge than measured
- Accelerated aging: high temperatures permanently damage cell chemistry, reducing cycle life
- Reduced thermal runaway threshold: the cell becomes more sensitive to physical damage, internal short circuits, and external abuse
A dry container in a tropical port (Yantian, Singapore, Long Beach in summer) can reach 50-60°C in the afternoon sun. That’s thermal runaway territory.
The Reefer Setup We Use
For our 6,500+ sea battery shipments, the standard reefer setup is:
- Set point: 15-25°C (we typically set 20°C as a safe middle ground)
- Ventilation: 15 CBM/hour fresh air exchange (default reefer setting)
- Humidity: 60-70% relative humidity (default reefer setting)
- Temperature monitoring: all modern reefers have data loggers; we pull the temperature record at destination
- Pre-cooling: we pre-cool the reefer to set point before loading the battery cargo (this is critical — loading warm cargo into a reefer doesn’t help)
The Reefer Surcharge
The reefer surcharge varies by route and season:
- $400-800 per 40HQ reefer container for China → US/Europe/Australia
- Higher in Q4 peak season (October-December) due to reefer equipment scarcity
- Plus the cost of the reefer container itself (vs. dry container): $50-150 per day usage
For a 40HQ reefer shipment from China to the US West Coast, the total reefer-related surcharge is typically $500-1,000. Compared to the cost of a single battery container fire ($500,000+ in ship, cargo, and port damage), it’s cheap insurance.
When You Can Skip the Reefer
For shipments under 200kg going to temperate destinations in cool months, a dry container is acceptable. Examples:
- 100kg of consumer power banks, Shenzhen to Hamburg in February
- 150kg of phone batteries, Shanghai to Rotterdam in November
- 50kg of watch batteries, Ningbo to Long Beach in January
The reefer is mandatory for: any shipment over 500kg, any shipment through tropical waters, any shipment in summer months (May-September for most routes), any shipment with SoC > 30%.
6. 6 Documents for Sea Battery (Checklist)
Document 01
UN38.3 Test Report & Summary
The foundational safety test report. Proves the battery model has passed the 8 mandatory environmental and mechanical stress tests.
Document 02
MSDS / SDS (16 Sections)
The chemical identity card of the battery. Outlines composition, emergency fire-fighting measures, and safe handling procedures.
Document 03
Marine Transport Test Report
A China-specific certification issued by authorized local labs (e.g., Shanghai Research Institute, CQC) verifying suitability for ocean transit.
Document 04
IMO Dangerous Goods Declaration
The formal shipper’s declaration for maritime transport. Contains critical cargo details including correct Stowage Categories.
Document 05
Dangerous Goods Packaging Certificate
Officially known as 出境危险货物运输包装使用鉴定结果单. Proves that the outer UN-approved packaging matches the danger level of the goods.
Document 06
Commercial Invoice & Packing List
Standard trade documents, but heavily customized for DG. Must accurately reflect net/gross weights and detailed cell specifications.
The sea battery document set is similar to air, with two key differences: the Marine Transport Test Report (a China-specific requirement) and the IMO Dangerous Goods Declaration (sea-specific form). Here’s the complete checklist:
① UN38.3 Test Report + Test Summary
The UN38.3 report proves your battery passed the 8 mandatory tests. The Test Summary is the newer 7-field version. Both are needed.
Sea-specific gotcha: carriers now check the UN38.3 report at booking stage, not just at documentation stage. If your report doesn’t cover the latest UN38.3 edition referenced in Amendment 42-24, the booking is rejected.
② MSDS / SDS (Material Safety Data Sheet)
The battery’s chemical ID card. 16 sections covering composition, first aid, fire response, handling, storage. Must include UN number, Class 9 designation, flash point, emergency response procedures. English AND Chinese versions required for China-origin shipments.
Sea-specific gotcha: Section 14 (Transport Information) must reference IMDG Code Amendment 42-24 (not 41-22) for 2026 shipments. Carriers check this.
③ IMO Dangerous Goods Declaration (DGD)
The sea equivalent of the air DGD. Same 27 mandatory fields, but uses the IMO/IMDG form instead of the IATA form. Must be signed by a trained DG person.
Sea-specific gotcha: the “stowage category” must be correctly specified. Wrong stowage category can cause the carrier to refuse the booking or to load the container in the wrong place on the vessel.
④ Class 9 Hazard Label + ⑤ Lithium Battery Handling Mark
Two labels per package:
- Class 9 diamond: 100mm × 100mm minimum, black “9” underlined on orange background, same side of every package
- Lithium Battery Handling Mark: rectangular, 120mm × 110mm minimum, with battery symbol, “Lithium batteries” text, and handling instructions
⑥ Marine Transport Test Report
The China-specific document. This is a test report issued by a Chinese-certified lab (CTC, CQC, Shanghai Research Institute, etc.) that certifies the battery is suitable for sea transport under IMDG Code. The test verifies the battery’s compliance with IMDG-specific requirements (which differ slightly from UN38.3).
Sea-specific gotcha: this is the most often-missed document for non-Chinese shippers. If your supplier doesn’t provide a Marine Transport Test Report, you’ll be rejected at the Chinese export customs. Make sure your battery manufacturer has a current report for your battery model.
⑦ IMO Multimodal Dangerous Goods Form (sometimes required)
For shipments that will be transshipped (e.g., China → Singapore → US), some carriers require the IMO Multimodal Form in addition to the DGD. The form includes both the DGD information and multimodal transport routing details.
⑧ Container Packing Certificate (CPC) + VGM (Verified Gross Mass)
For FCL shipments, the CPC confirms how the container was packed and by whom. VGM is required under SOLAS regulations and must be provided to the carrier before the container is loaded onto the vessel. Both are now standard practice for Class 9 cargo.
7. 6 Real Case Studies (China → 5 Destinations + 2 Special Scenarios)
These are 6 real shipments from our 6,500+ ledger, anonymized but accurate on the numbers. The point is to show you what worked, what cost more than expected, and what to watch out for.
Case 1: Power Bank, 5,000kg, Yantian → Los Angeles (FCL Reefer)
A consumer electronics brand needed 5,000kg of 20,000mAh power banks (74Wh each) shipped from Yantian to LAX for a Q2 Amazon restock. The shipment was FCL reefer.
- UN: UN3480 (standalone battery)
- PI: P903
- SoC: 50% (no 30% limit at sea)
- Documentation: UN38.3 current, Marine Transport Test Report, MSDS, IMO DGD, Class 9 labels, Lithium Battery Handling Mark
- Container: 40HQ reefer, set to 20°C
- Cost: $2,400 ocean freight + $650 reefer surcharge + $350 documentation fee = $3,400 total
- Transit: 18 days door-to-door
- Result: shipped on time, no issues. The reefer temperature log showed stable 19-21°C throughout the voyage.
Case 2: E-Bike Battery, 18,000kg, Ningbo → Hamburg (40HQ Reefer)
A European e-bike brand needed 18,000kg (about 1,800 battery packs) of 48V 15Ah (720Wh) battery packs shipped from Ningbo to Hamburg. Full container, reefer required.
- UN: UN3480 (standalone battery)
- PI: P903
- SoC: 70% (sea doesn’t have the 30% rule)
- Documentation: full set, including the German receiver’s EORI number and the EU 2023/1542 carbon footprint declaration
- Container: 40HQ reefer, set to 18°C
- Cost: $3,200 ocean freight + $700 reefer surcharge + $450 documentation fee = $4,350 total
- Transit: 32 days door-to-door
- Result: shipped on time, cleared EU customs in 4 days. The carbon footprint declaration was checked but accepted.
Case 3: Solar BESS, 25,000kg, Shanghai → Sydney (FCL Reefer)
A residential solar installer needed 25,000kg of 10kWh LiFePO4 BESS modules shipped from Shanghai to Sydney. The shipment was 2x 40HQ reefer containers.
- UN: UN3480 (standalone BESS module)
- PI: P903
- SoC: 50%
- Container: 2x 40HQ reefer, set to 20°C
- Cost: $2,800 per container ocean freight + $700 reefer surcharge = $7,000 total
- Transit: 22 days door-to-door
- Result: shipped on time, AU customs cleared in 6 days. The RCM marking was pre-checked before shipment.
Case 4: Phone Replacement Batteries, 800kg, Shenzhen → Rotterdam (LCL)
A phone repair service needed 800kg of replacement phone batteries (8Wh each) shipped from Shenzhen to Rotterdam. LCL was chosen because the volume didn’t justify FCL.
- UN: UN3481 (in equipment — the retail packaging)
- PI: P906 (packed with equipment)
- Documentation: SP 188 exemption was considered, but the LCL warehouse required full DG documentation
- Container: LCL consolidation in a 40HQ reefer shared with other compatible cargo
- Cost: $130/CBM × 4 CBM = $520 plus LCL service fees
- Transit: 38 days door-to-door (slower because of LCL handling at both ends)
- Result: shipped, but the LCL warehouse rejected the cargo twice before accepting. Lesson: not all LCL warehouses accept Class 9 battery cargo.
Case 5: Sodium-Ion Battery (UN3551), 3,000kg, Guangzhou → LAX (NEW 2026)
A new-energy startup shipped its first commercial sodium-ion battery cells from Guangzhou to LAX in Q1 2026. This was one of the first commercial UN3551 shipments in the world.
- UN: UN3551 (sodium-ion standalone, 2026 NEW)
- PI: P903 (with sodium-ion provisions)
- SoC: 50%
- Documentation: UN38.3 (sodium-ion specific test), Marine Transport Test Report, MSDS, IMO DGD, Class 9 labels
- Container: 40HQ reefer, set to 20°C
- Cost: $2,600 ocean freight + $650 reefer surcharge = $3,250 total
- Transit: 19 days door-to-door
- Result: shipped, but Maersk initially rejected the booking because the booking system didn’t have UN3551 in the dropdown. After a 2-day back-and-forth and manual override, the booking went through. The carrier now has UN3551 in their system. This is the kind of friction you’ll encounter with new UN numbers in 2026.
Case 6: Damaged Battery (P910), 1,500kg, Ningbo → Houston (Special Approval)
A battery recycler needed 1,500kg of damaged/swollen LiFePO4 cells shipped from Ningbo to a US recycling facility. This required the most stringent PI and special carrier pre-approval.
- UN: UN3480 + SP 376 (damaged/defective)
- PI: P910 (most stringent)
- Documentation: full set + damage assessment report + carrier pre-approval + carrier-specific damaged battery protocol
- Container: 40HQ dry container with extra safety measures (double-sealed, special placards)
- Cost: $8,500 ocean freight + $2,200 P910 surcharge + $1,500 special documentation + $1,200 carrier approval = $13,400 total
- Transit: 28 days door-to-door
- Result: shipped, but required 3 weeks of advance planning for the carrier pre-approval. The shipping line (MSC) conducted a remote inspection of the cargo before approval.
The common thread: every successful sea battery shipment was planned at least 2 weeks in advance, had the full documentation set ready before booking, and matched the carrier’s specific requirements. The ones that got rejected tried to skip a step or assume the old rules still applied.
8. 2026 Sea Freight Costs (China → 5 Destinations)
Battery Sea Freight Estimator (2026)
Box(es)
Enter the total number of containers for this battery batch.Real numbers from our recent bookings, all-in including documentation, reefer surcharge, and carrier fees. Use these as a planning baseline.
Sea Freight Cost Per 40HQ Reefer Container (USD, all-in, 2026)
Origin → Destination | Transit | FCL Reefer (40HQ) | DDP per CBM (1-15) | DDP per CBM (15-50) | DDP per CBM (50+) |
|---|---|---|---|---|---|
China → USA (LAX/LGB via SHA/NGB) | 16-22 days | $2,200-3,800 | $200-350 | $160-260 | $130-200 |
China → USA East Coast (NYC/SAV) | 28-35 days | $2,800-4,200 | (price unavailable) | (price unavailable) | (price unavailable) |
China → UK (Felixstowe via SHA) | 28-35 days | $2,500-4,000 | $250-400 | $200-300 | $160-240 |
China → EU (Rotterdam/Hamburg) | 28-38 days | $2,500-4,200 | $250-400 | $200-300 | $160-240 |
China → Australia (Sydney/Melbourne) | 18-25 days | $2,800-4,000 | $300-450 | $250-350 | $200-300 |
China → Canada (Vancouver/Montreal) | 22-30 days | $2,500-3,800 | $250-400 | $200-300 | $160-240 |
Cost Breakdown Per Container
A $3,000 40HQ reefer battery shipment from China to the US typically breaks down as:
- Ocean freight base: $2,000-2,400 (60-70% of total)
- Reefer surcharge: $400-700 (15-20%)
- Documentation fee: $300-500 (10-15%)
- Carrier DG surcharge: $200-400 (5-10%)
- Insurance (0.3-0.5% of cargo value): $150-300 (5-10%)
LCL vs FCL Cost Comparison
For a 10 CBM battery shipment from China to the US:
- LCL: ~$130/CBM × 10 = $1,300 (plus LCL fees, total $1,500-1,800)
- FCL (if you can fill 50+ CBM with other compatible cargo or pay for the full container): $3,000 / 50 CBM = $60/CBM (much cheaper per CBM, but you need the volume)
The breakeven for FCL vs LCL is usually around 15-20 CBM. Below that, LCL is more cost-effective. Above that, switch to FCL.
When to Choose Sea Over Air
Shipment | Sea | Air |
|---|---|---|
< 100kg, urgent | Not economical | $5-10/kg, 1-3 days  |
100-500kg, regular | $2-5/kg, 15-30 days | $6-9/kg, 2-3 days |
500-2,000kg, regular | $2-4/kg, 15-30 days | $5-7/kg, 2-3 days |
2,000+kg, regular | $1-3/kg, 15-30 days | $4-6/kg, 2-3 days |
Damaged batteries | Sea only (air prohibited) | N/A |
Sodium-ion | Either (UN3551/3552 accepted by both) | Either |
9. 5 Major Shipping Lines (What Each One Is Good At)
MAERSK
The Premium ChoiceMaersk Line
The industry benchmark for structured dangerous goods safety audits. Known for having the most transparent, clear battery acceptance policy globally.
- Best For: High-value BESS modules & EV battery packs.
- Core Strength: Dedicated global DG expert desk; rapid 24-hour booking approval.
- Acceptance: Full scope for UN3480/3481, UN3551/3552, and UN3556-3558.
MSC
Capacity KingMediterranean Shipping Co.
The world’s largest container line by capacity. Offers unparalleled space allocation and flexible routing option parameters out of China ports.
- Best For: Mass-volume standalone UN3480 contract logistics.
- Core Strength: Stable space allocation even during Q4 peak season. Highly competitive contract rates.
- Acceptance: Excellent support for heavy tier Class 9 containers on long-haul routes.
CMA CGM
Transpacific ExpertCMA CGM
The go-to carrier for US and European premium services. Exceptional terminal priority and intermodal rail connections across North America.
- Best For: Fast-transit battery shipments to US West/East Coast.
- Core Strength: EXX/EX1 express lines offer guaranteed loading and fast discharge slots at LAX.
- Acceptance: Strict technical review on UN38.3 test summaries but highly reliable once approved.
HAPAG-LLOYD
Reefer SpecialistHapag-Lloyd (HPL)
Renowned for its state-of-the-art reefer container fleet. Exceptional choice when strict 15-25°C active cooling telemetry is required.
- Best For: Trans-oceanic routes through tropical waters in summer.
- Core Strength: Industry-leading IoT live remote temperature tracking and strict cell-stability monitoring.
- Acceptance: Preferred carrier for large-scale energy storage battery container projects.
ONE
Intra-Asia NetworkOcean Network Express
The magenta fleet features an optimized layout for Intra-Asia, Japan, and Latin American trade corridors. Extremely nimble customer support.
- Best For: High-frequency regional shipments (E-bikes / Consumer electronics).
- Core Strength: Fast approval for 2026 newly classified UN3551 Sodium-ion volumes.
- Acceptance: Flexible packaging requirements for SP188 exempt battery goods.
Not all ocean carriers accept battery cargo the same way. Here’s our practical guide to the 5 carriers that matter most for China-origin sea battery freight.
Maersk — The Premium Choice
The world’s largest container line, and the most well-documented battery policy. Maersk publishes a clear acceptance procedure for Class 9 dangerous goods including lithium batteries.
- Strengths: Well-documented procedures, dedicated DG team, global network, transparent pricing
- Battery acceptance: Class 9 (UN3480, UN3481, UN3090, UN3091, UN3551, UN3552) accepted on most routings
- Limitations: Some peak season capacity issues; book 2-3 weeks in advance for guaranteed loading
- Pricing: Premium (10-15% higher than CMA CGM/COSCO for some routes)
- Best for: high-value cargo, complex documentation, when you need a “no surprises” experience
MSC — The Volume Leader
The second-largest container line, with strong direct routings from China to most major destinations.
- Strengths: High capacity, competitive pricing, strong China-US network
- Battery acceptance: Most Class 9 accepted, but acceptance is decided “case-by-case” per their published guidelines
- Limitations: Documentation review can be slower than Maersk
- Pricing: Mid-range (5-10% lower than Maersk for similar routes)
- Best for: large volumes, price-sensitive shipments, China-US East Coast routes
CMA CGM — The French Option With Wide Acceptance
The third-largest line, with strong European connections.
- Strengths: Strong China-Europe network, accepts most battery types, publishes detailed IMDG 42-24 summary (one of the first to do so)
- Battery acceptance: Comprehensive, including damaged batteries under P910 with pre-approval
- Limitations: US network less developed than Maersk/MSC
- Pricing: Competitive for Europe, slightly higher for US
- Best for: China-Europe routes, when you need to ship damaged batteries
COSCO — The Chinese National Champion
The Chinese state-backed line, with the deepest China domestic network and strong transpacific routes.
- Strengths: Domestic China expertise, strong transpacific, accepts all battery types
- Battery acceptance: Comprehensive, including new 2026 UN numbers (UN3551, UN3552)
- Limitations: Less strong on China-Europe direct services compared to CMA CGM
- Pricing: Often the most competitive for China-US routes
- Best for: China domestic + transpacific, when you need Chinese-language support
Hapag-Lloyd— The German Specialist
A German line with strong European connections and high service quality.
- Strengths: Excellent European service, high reliability, accepts battery cargo
- Battery acceptance: Standard Class 9, with extra scrutiny on damaged/defective batteries
- Limitations: Limited China-US direct services
- Pricing: Mid-to-premium
- Best for: China-Europe routes when you need premium service
Our Practical Recommendation
For a standard 40HQ reefer battery shipment from China to the US, we typically book Maersk or COSCO with MSC as the price-shopping alternative. For China to Europe, CMA CGM or Hapag-Lloyd. For China to Australia, Maersk or COSCO. The “right” carrier depends on your origin city, destination, and shipment size.
One important note for 2026: all 5 carriers have updated their booking systems to accept the new UN numbers (UN3551, UN3552, UN3556-3558), but system errors are still common. If you’re booking sodium-ion or battery-powered vehicles, confirm the booking manually after submission.
10. 8 Common Sea Battery Mistakes (And How to Avoid Them)
The same mistakes keep showing up in our 6,500+ sea battery shipments. The first 3 account for about 60% of sea rejections. Here’s the full list:
1. Wrong UN number on the DGD. UN3480 (standalone) vs UN3481 (in/with equipment) — a one-digit difference that completely changes the rules. Mix them up and the carrier rejects at booking. For 2026, also watch for UN3551/3552 (sodium-ion) and UN3556-3558 (vehicles). The fix: confirm the UN number with your battery manufacturer before booking, and double-check against the actual physical configuration.
2. UN38.3 report expired or missing. Reports are valid 3-5 years. Battery manufacturers forget to renew. Carriers check at booking. Expired or missing report = no booking. The fix: track the expiration date of your UN38.3 report in a calendar reminder, and start the renewal process 6 months before expiration.
3. Marine Transport Test Report missing or outdated. The China-specific document that Chinese customs check. If your supplier provides a UN38.3 report but no Marine Transport Test Report, your cargo will be stuck at export customs. The fix: ask your battery manufacturer for a current Marine Transport Test Report aligned with IMDG 42-24.
4. Wrong packing instruction on the DGD. PI 903 vs 904 vs 905 vs 906 vs 910 — each is for a different scenario. Using P903 for damaged batteries (which need P910) is the most common mismatch. The fix: confirm the PI matches the physical condition of your battery (new vs damaged vs defective).
5. Class 9 label missing, wrong size, or wrong color. Every package needs a Class 9 diamond, 100mm × 100mm minimum, black “9” underlined on orange background. We’ve seen labels that are too small (50mm × 50mm), wrong color (yellow background instead of orange), or placed on the bottom of the box. The fix: order labels from a certified DG label supplier (not generic warning labels), check size with a ruler, and put them on the same side of every package.
6. No reefer for tropical routes or large shipments. Putting a 20,000kg battery shipment in a dry container going through Singapore in July is asking for trouble. The fix: reefer for any shipment over 500kg, any tropical route, any summer month. The USD 400-800 surcharge is cheap insurance.
7. Mixed battery types in one outer package without proper segregation. Power banks + e-bike batteries in one box, declared as “battery assortment.” Wrong. The fix: each battery type in its own package, with its own DGD line entry, with the correct UN number for that specific type.
8. Booking too late for reefer capacity. Reefer containers are in high demand (food, pharma, chemicals all use them). In Q4 peak season, reefer capacity can be tight. Booking 1 week before vessel departure means you might not get a reefer. The fix: book 2-3 weeks in advance during peak season, 1-2 weeks in off-peak.
The pattern: all 8 mistakes are preventable with 2-3 weeks of lead time and a complete documentation check before booking. The sea freight system has more capacity than air, but the documentation and packaging requirements are stricter in their own way.
11. FAQ — The 10 Questions We Get Every Week About Sea Battery Shipping
Q1: Can lithium batteries be shipped by sea from China?
Yes, under IMDG Code regulations. All lithium batteries (UN3480, UN3481, UN3090, UN3091) are accepted for sea transport with proper UN classification, packaging, and documentation. The current mandatory edition is IMDG Code Amendment 42-24, effective January 1, 2026.
Q2: Do I need a reefer container for sea battery shipping?
Strongly recommended for shipments over 500kg, any tropical route, or any summer month. The reefer keeps the temperature stable (15-25°C) and prevents thermal runaway risk. The surcharge is USD 400-800 per 40HQ container — cheap insurance against a much larger loss.
Q3: What is IMDG Code 42-24 and when did it become mandatory?
IMDG Code Amendment 42-24 is the 2024 edition of the International Maritime Dangerous Goods Code. It became mandatory on January 1, 2026, with a voluntary compliance period throughout 2025. Major changes: new UN numbers for sodium-ion (UN3551/3552) and battery-powered vehicles (UN3556-3558), tighter Class 9 labeling enforcement.
Q4: What is the difference between UN3480 and UN3481 for sea freight?
UN3480 covers lithium-ion batteries shipped alone (no equipment). UN3481 covers lithium-ion batteries shipped packed with or contained in equipment. The packaging instruction differs (P903 vs P905/P906), the documentation differs, and the carrier acceptance can differ. Most importantly: the DGD must match the physical configuration exactly.
Q5: How much does it cost to ship lithium battery by sea from China?
For 2026: USD 1,800-3,500 per 40HQ reefer container FCL (depending on destination); USD 90-140 per CBM for DDP door-to-door; USD 2-5 per kg for LCL all-in. Sea is 60-80% cheaper than air for shipments over 500kg.
Q6: How long does sea battery shipping take from China?
15-35 days depending on destination. US West Coast 16-22 days. US East Coast 28-35 days. Europe 28-38 days. Australia 18-25 days. Canada 22-30 days. Add 3-7 days for origin pickup and destination delivery.
Q7: Can I ship damaged or recalled lithium batteries by sea?
Yes, under Packing Instruction P910 and Special Provision 376. Air transport is prohibited for damaged/defective batteries. Sea is the realistic option. Cost is 3-5x normal battery shipping, and carrier pre-approval is required (typically 2-3 weeks lead time).
Q8: What is Special Provision 188 (SP 188) and when does it apply?
SP 188 is the IMDG exemption for small lithium cells and batteries. For Li-ion: ≤20Wh per cell, ≤100Wh per battery. For Li-metal: ≤1g per cell, ≤2g per battery. If your batteries meet these thresholds AND have a current UN38.3 test AND are in proper packaging, you can ship under SP 188 with simplified documentation (no full DGD, no Class 9 label required, but still need Lithium Battery Handling Mark).
Q9: Can I ship sodium-ion batteries by sea in 2026?
Yes, under UN3551 (standalone) or UN3552 (in equipment). Both are Class 9 dangerous goods, similar documentation to UN3480/UN3481, with sodium-ion specific test requirements. New for 2026 — expect some carrier system issues in the early months as the new UN numbers roll out.
Q10: What is the Marine Transport Test Report and why do I need it?
The Marine Transport Test Report is a China-specific document that certifies your battery is suitable for sea transport under IMDG Code. It's issued by a Chinese-certified lab (CTC, CQC, Shanghai Research Institute) and is checked at Chinese export customs. Without it, your cargo will be held at origin. If your supplier is outside China, ask them to provide a current Marine Transport Test Report aligned with IMDG 42-24.
12. References & Sources
- IMDG Code, Amendment 42-24 (2024 Edition, mandatory January 1, 2026) — International Maritime Organization
- UN Recommendations on the Transport of Dangerous Goods, 21st Edition (Orange Book) — United Nations
- UN Manual of Tests and Criteria, 8th Edition, Section 38.3 — United Nations
- MSC.556(108) — Resolution adopting IMDG Code Amendment 42-24 — IMO Maritime Safety Committee
- CINS Guidelines for Shipping Lithium-ion Cells and Batteries in Containers (April 2026 Edition) — Cargo Incident Notification System
- Maersk Battery Shipping Policy (2026 Update) — A.P. Moller-Maersk
- CMA CGM IMDG Code 42-24 Detailed Summary — CMA CGM
- MSC Booking Guidance for Lithium Battery (May 2024) — Mediterranean Shipping Company
- CTU Code (Code of Practice for the Packing of Cargo Transport Units) — IMO/ILO/UNECE
- CSS Code (Code of Safe Practice for Cargo Stowage and Securing) — IMO
- CINS Lithium-ion Battery Incident Database — CINS
- BAT Internal Records (2024-2026) — 6,500+ battery shipment data, anonymized
What to do next: If you’re ready to ship lithium batteries by sea from China, the fastest path is a quote request with: (1) battery type and UN number, (2) Wh per battery and total quantity, (3) origin city and destination port, (4) preferred transit time, (5) FCL or LCL. We’ll come back with options, costs, and a clear documentation checklist within 24 hours.
For the air freight equivalent of this guide, see our Spoke #1: Shipping Lithium Battery by Air from China (IATA DGR 67th).
For a deep dive on the UN38.3 testing requirements, see our Spoke #13: UN38.3 Explained for Battery Shippers.
For damaged/defective battery shipping under P910, see our Spoke #5: Shipping Damaged Lithium Batteries (P910).
A note from the BAT team: This guide will be updated as IMDG Code amendments evolve and as major ports publish additional enforcement guidance. The next major update is expected for Q3 2026, when IMO is expected to publish refined guidance on the new UN3551/3552/3556-3558 categories. If you’re using this guide to plan a shipment more than 3 months out, double-check the IMDG Code edition in effect at your time of shipment. We publish monthly regulatory updates on our site.
Want to stay current? Subscribe to our battery shipping regulatory digest — we send a 5-minute monthly summary of what changed, what it means for your shipments, and what to do about it. No spam, no marketing fluff, just the changes.
