Battery Supply Chain > Battery Pack Gigafactories
Battery (Pack) Gigafactories
Battery packs are the system-level assemblies that integrate individual cells into modules and packs with the necessary electronics, cooling, and safety structures. While cells define chemistry and energy density, packs determine how effectively that energy is managed, delivered, and protected in the vehicle. Pack-level design is a major differentiator for automakers, impacting performance, safety, cost, and manufacturability. Gigafactories now dedicate entire production lines to pack assembly, often co-located with cell manufacturing to streamline logistics and ensure supply security.
EV battery worldwide market share
BYD = 16%. South Korea.
LG Energy Solution = 13%. South Korea.
Panasonic = 6%. Japan
SK On = 5%. South Korea
Samsung SDI = 4%. South Korea
CALB = 3%. China.
NOTE: EU-bound batteries require a digital passport starting 2027. See BatteryPassportGuide.com.
Battery pack manufacturing process overview
Battery pack plants convert finished cells (or modules) into vehicle-ready packs by integrating electrical interconnects, thermal management, and high-voltage safety hardware, then validating every pack with end-of-line testing. Unlike cell manufacturing, pack manufacturing is dominated by mechanical integration yield, leak-tight thermal assemblies, and test throughput.
- Incoming cells/modules and traceability: lots are verified, inspected, and (when needed) matched to reduce imbalance and variability.
- Electrical integration: busbars/interconnects are installed and joined (laser/ultrasonic welding or fastened joints); join quality is a primary yield driver.
- Thermal integration: cold plates, thermal interface materials, manifolds, and coolant plumbing are assembled; leaks and poor thermal contact are common failure modes.
- High-voltage safety integration: insulation barriers, HVIL (High-Voltage Interlock Loop), fuses/contactors/pyro fuses, and protective routing are installed.
- Pack enclosure build, sealing, and leak testing: trays and lids are sealed; robust leak testing protects against water ingress and corrosion.
- End-of-line validation: hipot/isolation, continuity, HVIL checks, and functional commissioning (BMS configuration) ensure safety and pack readiness.
For a full step-by-step breakdown (including bottlenecks and the equipment stack), see the Battery Pack Manufacturing Process page.
Battery Pack Components
Battery packs combine electrochemical cells with mechanical, electrical, and thermal subsystems to ensure reliable operation across vehicle lifetimes.
| Subsystem | Examples | Role |
|---|---|---|
| Structural Housing | Aluminum or composite casings, crash protection frames | Protects cells, integrates into chassis |
| Thermal System | Cooling plates, refrigerant loops, immersion cooling | Maintains safe temperature and fast charging capability |
| Electronics | BMS, BCUs, sensors, safety interlocks | Monitors pack performance and safety |
| Safety Systems | Fuses, contactors, fire-retardant coatings | Protects against overcurrent, thermal runaway |
Battery Pack Assembly
Pack assembly is increasingly integrated into gigafactories alongside cell production. This ensures quality control, reduces logistics costs, and allows automakers to customize packs to their vehicle platforms. Automated assembly lines handle welding, adhesive application, thermal system integration, and end-of-line testing.
| Region | Examples | Notes |
|---|---|---|
| North America | Tesla (Texas), GM Ultium, Ford-SK, Panasonic | Pack assembly co-located with cell factories; IRA incentives |
| Europe | Northvolt Sweden, ACC France, VW Salzgitter | Strong pack R&D integration with vehicle plants |
| Asia | CATL, BYD, LG Energy Solution, Samsung SDI | Dominant in both cell and pack system integration |
Battery Gigafactories
Gigafactories represent multi-billion-dollar investments and are increasingly clustered near automaker hubs to secure supply, reduce logistics costs, and meet domestic content rules. Here is a list of all lithium cell factories in the U.S. This is a list of all lithium battery gigafactories in the U.S. and the major ones worldwide. A large gigafactory can consume 2.4 GWh of electricity and 1 million gallons of water daily.Battery factories assemble the individual battery cells into a functioning battery pack with a battery management system (BMS) and thermal management system (TMS) and enclosure. Some battery pack factories also produce cells onsite, often in a joint partnership with a cell manufacturer (like Panasonic for example).
Here are the top 10 largest battery gigafactories in the world:
1. 126 GWh: CATL Liyang Plant - Jiangsu, China
2. 120 GWh: CATL Ningde Plant - Fujian, China
3. 100 GWh: CATL Yibin Plant - Sichuan, China
4. 100 GWh: Tesla Sparks Gigafactory - Nevada, USA
5. 86 GWh: BlueOval Glendale - Kentucky, USA
6. 60 GWh: BYD Chongqing Plant - Chongqing, China
7. 50 GWh: Ultium Cells Spring Hill - Tennessee, USA
8. 43 GWh: BlueOval City Stanton - Tennessee, USA
9. 41 GWh: Ultium Cells Lansing - Michigan, USA
10. 41 GWh: Ultium Cells Warren - Ohio, USA
U.S. battery pack factories
The reshoring and building of a domestic lithium battery supply chain is in full swing in the U.S., with a bevy of new EV battery pack and module manufacturing plants and factories coming online by 2028.
The states with the most EV battery module and pack factories are Michigan, Tennessee, South Carolina, and Georgia, which are known as the "Battery Belt".
Notable worldwide battery pack factories
Here are some of the major EV battery module and pack manufacturing factories worldwide, excluding China, which has the lion's share of battery factories.
Why They Matter
Battery packs determine not only vehicle range and performance but also crash safety, manufacturability, and serviceability. Innovations in pack architecture (CTP, structural integration) are becoming as strategic as cell chemistry itself. Control of pack gigafactories ensures automakers can deliver differentiated products and protect against supply shocks.
Supply Chain & Risks
Pack manufacturing depends on secure supply of casings, adhesives, thermal components, and electronics. Risks include shortages of aluminum for housings, specialty films and adhesives, and highly automated welding/assembly equipment. Structural packs raise new risks around repairability and crash validation. OEMs are localizing pack assembly near vehicle plants to mitigate logistics and trade risks.
Market Outlook & Adoption (Ranked)
| Rank | Pack Trend | Adoption Drivers | Constraints |
|---|---|---|---|
| 1 | Cell-to-Pack (CTP) | Higher density, lower cost per kWh, simplified assembly | Serviceability challenges; precise QA required |
| 2 | Structural Packs | Weight reduction, integration into chassis, cost savings | Crash safety testing; limits on pack swapping/reuse |
| 3 | Module-Based Packs | Proven, serviceable, widely deployed | Lower volumetric efficiency; heavier design |