Who Are the Top 10 Energy Storage Battery Manufacturers in the USA?

Choosing a battery supplier from a crowded market is difficult. An unsuitable manufacturer can create certification, delivery, integration, warranty, and long-term service problems.

The leading energy storage battery manufacturers operating in the USA include Tesla Energy, LG Energy Solution, Fluence, Form Energy, Eos Energy, Saft America, Stryten Energy, ESS Inc., EnerSys, and East Penn Manufacturing. I compare them by U.S. production, product maturity, application range, technology, safety support, and long-term manufacturing capability.

I use “manufacturer in the USA” to include companies with meaningful battery-cell, module, pack, enclosure, or complete energy storage system production in the country. Some companies are American-owned, while others are international groups with major U.S. factories. This list is an editorial comparison as of August 2026, not an audited ranking by revenue or annual shipments.

Who Are the Top 10 Energy Storage Battery Manufacturers in the USA?

The U.S. market includes several types of battery manufacturers. Some companies produce lithium-ion cells. Some manufacture complete battery energy storage systems. Others focus on long-duration iron, zinc, flow, or lead-based technologies.

My top 10 list includes manufacturers with active U.S. production, clear stationary energy storage products, commercial projects, and enough technical depth to support serious residential, commercial, industrial, or utility applications. I do not rank companies only by factory size because technology fit, system integration, warranty support, and project bankability also matter.

Rank	Manufacturer	Main technology	Primary market
1	Tesla Energy	LFP lithium-ion systems	Utility, commercial, and residential
2	LG Energy Solution Michigan	LFP lithium-ion cells	Utility and commercial BESS
3	Fluence	Integrated lithium-ion BESS	Utility-scale storage
4	Form Energy	Iron-air batteries	Multi-day grid storage
5	Eos Energy Enterprises	Aqueous zinc batteries	Long-duration utility and industrial storage
6	Saft America	Industrial lithium-ion systems	Utility, commercial, and critical infrastructure
7	Stryten Energy	Lead, lithium, and vanadium flow	Industrial, microgrid, and reserve power
8	ESS Inc.	Iron-flow batteries	Commercial and utility long-duration storage
9	EnerSys	Lead and lithium industrial batteries	Data centers, telecom, industrial, and reserve power
10	East Penn Manufacturing	Lead-based storage batteries	Renewable energy, UPS, telecom, and utility backup

1. Tesla Energy

I place Tesla Energy first because it combines large-scale U.S. manufacturing, complete system integration, software, power electronics, and experience across residential and utility markets.

Tesla manufactures Megapack systems at its Megafactory in Lathrop, California. Tesla states that the facility can produce 10,000 Megapacks per year, equal to 40 GWh of annual energy storage capacity. The Megapack integrates battery modules, thermal management, power electronics, controls, and monitoring into a factory-built utility-scale product.

Tesla also supplies Powerwall for residential and small commercial applications. This gives the company a wider market range than manufacturers that focus only on grid-scale projects.

I see Tesla as a strong candidate when a buyer needs:

• A complete rather than component-level system
• Large utility-scale deployment
• Integrated controls and monitoring
• Standardized factory production
• Residential and commercial product options
• An established service and software platform

Tesla does not publish every supply-chain detail for every system configuration. I therefore still verify cell origin, domestic-content eligibility, delivery timing, warranty terms, augmentation strategy, and local service responsibilities for each project.

2. LG Energy Solution Michigan

I rank LG Energy Solution highly because it manufactures battery cells rather than only assembling third-party cells into enclosures.

LG Energy Solution operates battery manufacturing facilities in Michigan. Its Holland facility began large-scale production of LFP cells for energy storage systems in 2025. Public reporting placed the new LFP production capacity at about 16.5 GWh per year, alongside existing battery production at the site. LG Energy Solution describes its Michigan operation as supporting electric vehicles, industrial products, and energy storage applications.

This U.S. cell-production capability is important because many American BESS suppliers still depend on imported cells. Domestic cell manufacturing can help a project meet sourcing requirements and reduce some transport or trade risks.

I consider LG Energy Solution a strong option for:

• Utility-scale LFP battery cells
• Commercial battery systems
• Domestic-content-focused projects
• Original equipment manufacturers
• System integrators needing a high-volume cell supplier

LG Energy Solution is primarily a cell and battery technology supplier. A project may still require another company to provide enclosures, inverters, energy management software, fire controls, commissioning, and long-term system integration.

3. Fluence

I include Fluence because it is one of the most important U.S.-based manufacturers and integrators of complete grid-scale battery energy storage systems.

Its Gridstack Pro platform integrates battery modules, management systems, controls, monitoring equipment, and safety features into a unified utility-scale architecture. Fluence offers configurations designed for common two-hour and four-hour grid applications.

Fluence has also expanded its domestic supply chain. The company states that Gridstack Pro can use 305Ah LFP cells manufactured in Tennessee. Those cells are incorporated into U.S.-manufactured modules and assembled into Gridstack Pro enclosures. Fluence began production of thermal management equipment for the platform at a Houston facility in 2025 and delivered its first domestically produced Gridstack Pro systems later that year.

I see Fluence as a strong choice for:

• Large front-of-the-meter BESS projects
• Utility and independent power producer applications
• Domestic-content procurement
• Integrated performance management
• Long-term service agreements
• Projects that require advanced bidding or asset software

Fluence is better described as a BESS manufacturer and system integrator than as an independent cell manufacturer. Buyers should confirm which cell supplier, chemistry, module, inverter, and domestic-content configuration applies to the proposed project.

4. Form Energy

I include Form Energy because it addresses a problem that standard lithium-ion batteries do not solve economically in every case: multi-day energy storage.

Form Energy manufactures iron-air battery systems at Form Factory 1 in Weirton, West Virginia. The company describes the 550,000-square-foot facility as its first high-volume manufacturing site. It expects the factory to expand to at least 500 MW of annual battery production capacity by 2028.

The company’s iron-air battery is designed to discharge for up to 100 hours. It stores and releases energy through a reversible oxidation process involving iron, water, and air. This long duration makes the system different from lithium-ion products commonly designed for daily two-to-four-hour cycling.

I consider Form Energy for:

• Multi-day renewable energy balancing
• Grid resilience during extended weather events
• Replacement of retiring fossil-fuel capacity
• Large utility projects with long discharge requirements
• Projects where land is available
• Applications that value low-cost storage materials

Form Energy is still building its commercial operating record compared with mature lithium-ion suppliers. I would review project milestones, performance guarantees, factory output, delivery schedules, footprint, auxiliary consumption, and long-term maintenance before procurement.

5. Eos Energy Enterprises

I rank Eos Energy among the leading U.S. manufacturers because it designs and manufactures a non-lithium, zinc-based battery system in Pennsylvania.

Eos describes its Z3 technology as a U.S.-manufactured energy storage solution based on an aqueous zinc chemistry. The company manufactures and assembles its systems in the Pittsburgh area and states that its products use a predominantly U.S.-based supply chain.

The company has been expanding beyond its existing Turtle Creek factory. In 2025, Eos announced another Pennsylvania manufacturing facility and a plan to reach 8 GWh of annualized energy storage production capacity. It also introduced its Indensity platform in January 2026 and launched commercial production from another manufacturing line in June 2026.

I consider Eos for:

• Utility and industrial long-duration storage
• Sites concerned about lithium-ion fire behavior
• Projects seeking high domestic content
• Microgrids and critical infrastructure
• Applications requiring repeated cycling
• Projects that value material and supply-chain diversity

I would still compare round-trip efficiency, site footprint, operating temperature, project duration, degradation, bankability, and service guarantees with competing lithium-ion and flow-battery products.

6. Saft America

I include Saft America because it combines a long industrial battery history with active U.S. production of lithium-ion energy storage equipment.

Saft commissioned an additional production line at its Jacksonville, Florida, factory in 2024 to manufacture lithium-ion battery containers for the energy storage market. The company’s Intensium Flex product is a ready-to-install containerized battery building block for utility and commercial energy storage systems. Saft states that its Intensium containers are manufactured in Jacksonville as well as at its facility in Zhuhai, China.

Saft is owned by TotalEnergies, so it is not an American-owned company. I include it because it has a real manufacturing operation in the United States and supplies systems for American projects.

I consider Saft for:

• Utility-scale lithium-ion BESS
• Commercial and industrial storage
• Critical infrastructure
• Harsh environmental conditions
• Customers seeking an established industrial battery supplier
• Projects requiring containerized systems

Buyers should confirm whether a quoted system comes from the Jacksonville line, what percentage of the equipment is domestically produced, and which company supplies the inverter, transformer, software, and long-term field service.

7. Stryten Energy

I include Stryten Energy because it offers one of the broadest chemistry portfolios among U.S. energy storage manufacturers.

Stryten supplies advanced lead, lithium, and vanadium-based storage products. The company serves microgrids, transportation, material handling, telecommunications, reserve power, and industrial applications. It states that its batteries are produced across a large network of U.S. plants. In July 2026, Stryten announced an acquisition that would increase the combined group’s U.S. manufacturing footprint to 15 plants.

This broad manufacturing base makes Stryten different from a company focused on one lithium-ion container platform.

I consider Stryten for:

• Microgrids
• Industrial backup
• Telecommunications
• Material handling
• Critical power
• Vanadium flow applications
• Lead-battery systems with established recycling routes
• Customers seeking several chemistries from one supplier

I would identify the exact business unit and technology before comparing a Stryten proposal. A lead battery, lithium battery, and vanadium flow system have very different power, duration, maintenance, footprint, and lifecycle characteristics.

8. ESS Inc.

I include ESS Inc. because it manufactures long-duration iron-flow battery systems in Oregon.

The company uses an electrolyte based on iron, salt, and water. Its products target commercial and utility-scale long-duration storage rather than the short-duration, high-energy-density market dominated by lithium-ion systems. ESS operates a manufacturing facility and headquarters in Wilsonville, Oregon.

ESS continued commissioning projects in 2026. In May, the company announced the successful commissioning of two iron-flow systems for the Turlock Irrigation District’s solar-over-canal project in California.

I consider ESS for:

• Long-duration daily cycling
• Renewable energy shifting
• Microgrids
• Utility and commercial projects
• Sites that value a water-based electrolyte
• Projects with enough space for flow-battery equipment

ESS is smaller than the largest lithium-ion manufacturers. I would carefully review its balance sheet, manufacturing scale, warranty support, spare-parts plan, efficiency, project references, and long-term service capability.

9. EnerSys

I include EnerSys because it is a large, established U.S.-headquartered manufacturer of industrial batteries, chargers, reserve-power systems, and critical-power equipment.

EnerSys operates several manufacturing facilities in the United States. Its Richmond, Kentucky, plant has produced lead-acid batteries since 1977, while its Warrensburg, Missouri, site manufactures thin-plate pure-lead products for industrial and commercial energy storage applications.

The company has also selected Greenville, South Carolina, for a proposed lithium-ion cell gigafactory. That project represents future manufacturing capacity rather than an established operating cell factory, so I do not count the planned output as current production.

I consider EnerSys for:

• Data centers
• Telecommunications networks
• Industrial backup
• Uninterruptible power supplies
• Transportation and motive power
• Defense and critical infrastructure
• Customers requiring national service coverage

EnerSys is not primarily a utility-scale, four-hour lithium-ion BESS supplier. Its strength is established industrial and reserve-power manufacturing, so I compare it with grid-focused manufacturers only when the applications overlap.

10. East Penn Manufacturing

I include East Penn Manufacturing because it operates a major domestic battery-production complex and has a long record in reserve and renewable-energy storage.

East Penn describes its Pennsylvania operation as the world’s largest single-site lead-battery manufacturing facility. Its reserve-power portfolio serves telecommunications, data centers, UPS systems, switchgear, renewable energy, and other critical applications. The company manufactures AGM, gel, UltraBattery, and other lead-based energy storage products.

East Penn also emphasizes vertically integrated material processing, testing, battery production, and recycling. Its renewable-energy products are made at a single-site facility with technical centers that test raw materials and finished components.

I consider East Penn for:

• Renewable-energy backup
• Telecommunications
• Data centers and UPS applications
• Utility switchgear
• Industrial reserve power
• Projects that value mature lead-battery recycling
• Applications that do not require lithium-ion energy density

East Penn is not a direct substitute for a high-density utility LFP container in every project. Its products are strongest where proven reserve-power performance, established servicing, recyclability, and lead-battery technology fit the duty cycle.

Which Manufacturer Is Best for Grid-Scale Lithium-Ion Storage?

A familiar name does not automatically provide the best project result. Cell supply, system integration, software, guarantees, and local service all affect performance.

I place Tesla, Fluence, and LG Energy Solution at the front of the U.S. grid-scale lithium-ion market, but they perform different roles. Tesla supplies a tightly integrated complete system. Fluence provides configurable BESS platforms and software. LG Energy Solution manufactures cells that other system suppliers may integrate into complete projects.

I Separate Cell Makers From System Integrators

A cell manufacturer produces the electrochemical component that stores energy. A module manufacturer connects and protects groups of cells. A BESS integrator combines modules with power electronics, cooling, fire controls, monitoring, and site software.

Supplier type	Main responsibility	Example
Cell manufacturer	Cell chemistry and production quality	LG Energy Solution
Integrated product manufacturer	Complete factory-built battery product	Tesla Energy
BESS manufacturer and integrator	Modules, enclosures, controls, and project integration	Fluence
Long-duration technology manufacturer	Alternative chemistry and complete storage blocks	Form, Eos, and ESS
Industrial battery manufacturer	Reserve, UPS, telecom, and critical power batteries	EnerSys and East Penn

I avoid comparing cell capacity with complete-system capacity as though they are the same measurement. A 16 GWh cell factory does not automatically deliver 16 GWh of commissioned BESS projects. The cells still need modules, enclosures, inverters, software, installation, and grid approval.

I Compare Complete Performance Guarantees

For a utility-scale purchase, I ask which party guarantees:

• Initial usable energy
• End-of-warranty capacity
• Round-trip efficiency
• Continuous power
• Availability
• Auxiliary consumption
• Degradation
• Augmentation
• Response time
• Safety performance
• Spare-parts availability
• Software support

A low battery-cell price can become irrelevant when the final system has high installation cost, weak efficiency, frequent outages, or unclear warranty responsibility.

Which U.S. Manufacturers Specialize in Long-Duration Storage?

Lithium-ion batteries dominate many two-to-four-hour projects, but longer grid events can require a different cost and technology structure.

Form Energy, Eos Energy, and ESS Inc. are three important U.S. long-duration battery manufacturers. Form uses iron-air chemistry for multi-day storage. Eos uses aqueous zinc batteries. ESS uses iron-flow technology. I compare them by discharge duration, efficiency, footprint, manufacturing scale, project maturity, serviceability, and total lifecycle cost.

Long Duration Changes the Design Priorities

A short-duration battery needs high power, fast response, and strong daily cycling performance. A multi-day system needs low energy-capacity cost and practical storage over much longer periods.

Energy density may become less important when a project has enough land. Material availability, electrolyte stability, pump requirements, auxiliary consumption, and system complexity may become more important.

Technology	Main advantage	Main issue I examine
Iron-air	Multi-day discharge capability	Footprint and commercial operating history
Aqueous zinc	Non-lithium chemistry and domestic production	Efficiency and large-scale project references
Iron-flow	Long cycling life and water-based electrolyte	Pumps, footprint, and supplier scale
LFP lithium-ion	High efficiency and mature supply chain	Cost growth at very long durations

I do not assume that longer duration is always better. A two-hour frequency or peak-shaving project may not benefit from a 100-hour battery. I match the storage duration to the actual grid problem.

How Should I Choose a U.S. Energy Storage Battery Manufacturer?

The manufacturer’s name is only the beginning of a procurement decision. A strong project needs compatible equipment, documented testing, reliable delivery, and long-term support.

I choose an energy storage battery manufacturer by checking its active production capacity, chemistry, certifications, project references, financial stability, delivery history, inverter compatibility, warranty terms, safety testing, software ownership, spare-parts strategy, and service network. I also confirm whether “made in America” applies to cells, modules, enclosures, controls, or only final assembly.

I Verify Domestic Manufacturing Claims

The phrase “U.S.-made” can describe several different supply-chain structures.

A supplier may manufacture cells in the United States but import modules or electronics. Another may import cells but manufacture modules and enclosures domestically. A third may perform only final assembly in the country.

I ask for a bill of materials and manufacturing-location statement when domestic content affects tax credits, public procurement, national security, or project financing.

I Review Technical and Commercial Risk Together

I use a structured supplier comparison:

Evaluation area	Questions I ask
Manufacturing	Which components are made at which facility?
Capacity	What is the current output rather than planned output?
Safety	Are the complete system and tested configuration documented?
Certification	Does the proposed model meet applicable U.S. standards?
Performance	What energy, power, efficiency, and availability are guaranteed?
Degradation	Who pays for augmentation or replacement?
Integration	Which inverters and energy management systems are approved?
Software	Who owns, updates, and supports the controls?
Service	Are technicians and spare parts available near the project?
Finance	Can the supplier support a 10-to-20-year warranty obligation?
References	Are comparable systems already operating?
End of life	Who handles removal, reuse, and recycling?

I give financial stability the same attention as technical performance. A battery may operate for more than a decade, so the manufacturer or warranty provider must remain capable of supplying software, service, and replacement components.

My Insights: Who Are the Top 10 Energy Storage Battery Manufacturers in the USA

I believe a useful top-10 list must show more than company size. It must explain which part of the energy storage problem each manufacturer is equipped to solve.

The top U.S. energy storage battery manufacturers are Tesla Energy, LG Energy Solution, Fluence, Form Energy, Eos Energy, Saft America, Stryten Energy, ESS Inc., EnerSys, and East Penn Manufacturing. Their strengths range from high-volume LFP systems and domestic cell production to multi-day iron, zinc, flow, and reserve-power technologies.

I Do Not Expect One Manufacturer to Lead Every Segment

Tesla may be the strongest integrated choice for standardized lithium-ion products. LG Energy Solution may be more relevant when a system manufacturer needs domestic LFP cells. Fluence may be stronger when a utility needs system integration, software, and long-term services.

Form Energy, Eos, and ESS address longer-duration applications. Stryten, EnerSys, and East Penn have broader industrial or reserve-power backgrounds. Saft connects industrial battery experience with containerized lithium-ion storage.

The best manufacturer therefore changes with the application.

Domestic Production Is Becoming a System-Level Question

I no longer ask only where the battery cell is made.

I also ask where the module, enclosure, inverter, transformer, cooling system, BMS, energy management system, and fire-protection equipment are made. These parts affect cost, project eligibility, cybersecurity, delivery risk, and maintenance.

A project with U.S.-made cells can still depend heavily on imported electronics. A system with imported cells may still create significant domestic value through module production, enclosure manufacturing, engineering, software, and commissioning.

Technology Diversity Strengthens the U.S. Market

Lithium-ion will remain central to short-duration and daily storage. However, the American manufacturing market is becoming more diverse.

Iron-air, aqueous zinc, iron-flow, vanadium flow, advanced lead, and other systems give utilities more options. This diversity reduces dependence on one chemistry and helps buyers match battery characteristics to the required duration.

I see this as the main strength of the U.S. manufacturing landscape. The market includes high-volume lithium-ion suppliers, complete BESS integrators, long-duration technology developers, and established industrial battery companies.

I Treat the Top 10 as a Shortlist, Not a Final Decision

A ranking cannot replace project-level due diligence.

I would begin with two or three manufacturers that fit the required chemistry and duration. I would then compare technical offers, tested configurations, warranties, degradation models, delivery schedules, system pricing, service coverage, and project references.

The strongest supplier is not always the company with the largest factory. It is the company that can deliver the required system, document its performance, support it locally, and remain responsible throughout its operating life.

Conclusion

The leading U.S. battery manufacturers serve different markets. I choose among them by matching technology, duration, domestic production, safety, warranties, and long-term support to the project.