The short version
Key points
- The factory produces residential, commercial and industrial energy storage systems, including the CQ7, EP6 Plus and EP12.
- Fox ESS says Phase II has an automation rate above 75%, with five battery assembly lines and two fully automated lines.
- The batteries use LFP, or lithium iron phosphate, chemistry.
- Production includes automated PCB assembly, optical inspection, module welding, safety checks and end-of-line testing.
- The battery housing includes a standalone aerosol fire suppression system with its own heat sensor, according to Fox ESS.
A large-scale battery manufacturing operation
Fox ESS’s Wenzhou Phase II Smart Factory is one part of a wider manufacturing operation. Phase I and Phase II are running, while Phase III and Phase IV are under construction. Fox ESS says the total planned capacity across the wider operation is 50 gigawatts.
The company has more than 5,000 employees, including more than 500 in research and development, according to the information presented during the factory visit. The site produces residential batteries as well as commercial and industrial energy storage systems.
From components to circuit boards
The manufacturing process begins with electronics. On the automated surface-mount technology line, solder paste is printed onto printed circuit boards before components are placed. Machines pick chips from reels and position them on the boards, with optical systems checking component placement.
The boards then pass through an oven to set the solder before automatic depaneling separates a larger board into individual sections. Other machines insert components with pins, while workers continue to install parts that are not yet automated. The boards pass through another soldering stage, cooling section and optical inspection station. Fox ESS says some soldering faults can be detected and corrected automatically.
Battery assembly and LFP chemistry
On the battery assembly floor, five lines assemble products including the CQ7, EP6 Plus and EP12. Two of the five lines are fully automated. Robotic systems bring battery cells together into modules, which are then welded, fastened and checked.
The batteries use LFP, or lithium iron phosphate, chemistry. The transcript describes LFP as being associated with safety, long cycle life, thermal stability, lower cost and no cobalt use. The video also notes that the CQ7 is intended for the Australian market, where batteries may be installed in hot garages or on exposed outside walls.
A heater is included in the production process because LFP batteries can lose available capacity in cold conditions. The heater is intended to keep the battery at the temperature required to deliver the performance stated on its label.
Welding, inspection and protection
Busbar welding creates the electrical connections between battery cells. Fox ESS says its automated equipment can complete up to six welding points in one operation, aiming to improve speed, precision and consistency.
Quality control takes place throughout production. Checks include incoming materials, module welding, screw locking, safety testing, gas-tightness testing, operating-condition testing and end-of-line checks. Before shipping, the enclosure, labels, appearance, model, specifications, quantity and packaging are also inspected.
The battery housing contains a standalone aerosol fire suppression system with its own heat sensor. According to Fox ESS, it can activate automatically if the temperature inside the enclosure reaches a dangerous level. It operates independently of the inverter, software, communications and other main system electronics.
Automation, traceability and shipping
Fox ESS says artificial intelligence and automated systems are used for incoming material inspection, vision checks on cells and power components, assembly error-proofing, laser-welding monitoring, acoustic fingerprint monitoring and root-cause analysis. The factory also uses automated logistics, smart warehousing, dynamic scheduling and mixed-line production.
The company says recording checks during production allows it to track what happened, when it happened and where it occurred. Automated warehouse machinery moves products and components through the facility, reducing manual handling and helping the site manage production at scale.
At the end of the process, completed batteries undergo testing, final inspection, packaging and box sealing before being sent to distributors, installers, businesses or homes. Fox ESS says the operation can produce around 4,000 ship-ready battery units per day.
TechManPat’s conclusion
After visiting the factory, I came away with the view that a home battery is much more than the box installed on a wall. It combines battery chemistry, electronics, automation, testing, quality control and logistics. For Australia, I found the CQ7’s focus on the local market and its LFP battery system particularly relevant, although the factory visit shows the manufacturing process rather than how the product will perform in every individual installation.
This knowledge-centre summary is based on the linked TechManPat video and reflects the information available when it was published. Check current pricing, availability and policies before acting.
