The short version
Key points
- Commercial electricity tariffs may include demand charges based on how heavily a business draws from the grid during a measured period.
- Peak shaving uses battery power to reduce the amount of electricity a business needs to draw from the grid during high-demand periods.
- SAJ’s CM2 cabinet has 261kWh of battery capacity and a rated output of 125kW.
- Battery capacity and power output are different measurements, and neither guarantees a particular backup runtime.
- A large battery does not automatically keep an entire site running during a blackout, because backed-up circuits, motor-starting loads and available output must be considered.
Why commercial batteries are different
Businesses can use batteries to store surplus solar and use it later, much like a home battery. However, commercial electricity bills may also include demand charges. These charges are linked to how heavily a site draws from the grid during a measured period, meaning one particularly busy interval can influence the monthly bill, depending on the tariff.
Air conditioning, machinery and vehicle chargers operating at the same time can create a high demand peak. A battery can supply part of that load, reducing the amount of power required from the grid. This is known as peak shaving. For example, if a site needs 200kW and the battery supplies 50kW, the grid supplies the remaining 150kW during that period. Whether this produces meaningful savings depends on the tariff and how the system is operated.
Inside the SAJ CM2 cabinet
The CM2 is a commercial and industrial battery cabinet with a rated output of 125kW and battery capacity of 261kWh. Kilowatts describe how much power the system can deliver at once, while kilowatt-hours describe how much energy it stores. Dividing the capacity by the rated output gives slightly more than two hours as a simple scale comparison, before allowing for losses, reserves and operating limits. That is not a promised backup runtime.
The cabinet is intended for commercial sites rather than homes. The video describes it as weighing about 2.5 tonnes, requiring suitable delivery and lifting equipment. Inside are lithium iron phosphate batteries, power conversion equipment, battery management and energy controls, along with liquid cooling, forced-air cooling for the power conversion equipment and fire suppression at the battery pack and cabinet levels. Proper installation and site planning remain important.
AC-coupled and hybrid systems
The CM2 belongs to SAJ’s AC-coupled offering. In practical terms, this allows storage to be added alongside an existing solar installation, with the battery connected on the alternating-current side. That may suit a business that already has solar and wants to add storage without replacing the entire arrangement.
SAJ also offers a hybrid system using the CH3 inverter with a compatible CB3 battery. This approach connects solar and battery equipment on the direct-current side and can be designed around grid supply, backup loads and a generator. For a remote farm, for example, solar could serve daytime loads and charge the battery, while the battery and generator cover other periods. This may help reduce diesel use while keeping essential equipment such as pumps operating.
Backup power is not automatic
A large battery does not mean that every load at a site will continue operating during a blackout. The system design needs to identify which circuits are backed up, account for motor-starting loads, consider the available power output and estimate how long the stored energy can last.
Commercial storage may also be used to shift energy away from expensive periods, store unused solar generation and manage demand peaks. SAJ’s elekeeper energy management platform provides monitoring, alarms and scheduling, with forecasting for solar generation, electricity demand and pricing. It can help determine whether the battery should charge, preserve capacity for later, retain a backup reserve or discharge to reduce a demand peak.
What businesses should assess
The business case depends on the site rather than the battery’s size alone. An Australian business considering storage should examine interval consumption data, its electricity contract, installation costs, local approvals, warranty terms, servicing requirements and the loads that genuinely need backup.
A site that already uses almost all of its solar as it is generated may have a different case for storage from one with unused weekend solar generation or expensive evening demand. Participation in a virtual power plant may also be possible in some circumstances, but this depends on local market access, compatible services and the commercial agreement. It is not automatic simply because the battery is connected to the internet.
TechManPat’s conclusion
My view is that SAJ’s commercial range is interesting because the hardware, solar integration and control software are designed to work together across sites such as farms, factories and hotels. The equipment may be useful where the energy data supports it, but the system needs to earn its place through measurable savings, reliable operation and the specific job it is required to do. This video was a business and technology overview, not a long-term performance test, and was produced as a paid collaboration with SAJ, which also supported the China visit.
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.
