Case Study: Fogstar 48V Batteries for Home Backup and Off-Peak Energy Savings

Designed to give a homeowner greater control over their energy use while providing dependable backup power, this residential battery installation combines Fogstar Energy lithium storage with Victron Energy equipment to deliver both resilience and long-term energy savings.

Installed by Always Off-Peak, the system was built to support off-peak charging, grid export, and reliable backup power during grid outages. From the outset, the design prioritised both cost efficiency and uninterrupted supply, ensuring the home remains powered even during extended power cuts.

Reliable Backup Power with Lower Energy Costs

The homeowner wanted the system to provide a dependable backup supply while also running a heat pump using off-peak electricity. Any excess energy could then be exported back to the grid, helping reduce ongoing electricity costs.

While saving money was a key objective, power security was just as important. As a government coder, the homeowner relies on a continuous power supply, making system reliability essential rather than optional.

Solar generation is planned to be added at a later date, so the system was designed from the start with future expansion in mind.

Fogstar Batteries at the Core of the System

At the heart of the installation are four Fogstar Energy 16.1kWh 51.2V lithium batteries, providing a substantial amount of usable energy storage for both everyday energy management and backup power.

Operating at 48V allows for efficient system performance, reduced current draw, and compatibility with larger residential and three-phase installations. Each Fogstar battery includes an integrated Battery Management System, supporting safe operation and protecting against electrical and thermal faults.

By designing the system around the battery storage from the outset, it forms a solid foundation for both current use and future solar integration.

Integrated Victron Energy System

The battery bank is paired with three Victron Energy MultiPlus-II 48/10000/140-100 230V inverters, providing stable, high-quality AC power across the property.

A Victron Energy Cerbo GX manages system monitoring and control, allowing performance and status to be checked easily. Backup switching ensures a smooth transition during power cuts, keeping essential loads running without interruption.

Quality Installation from Start to Finish

This was a sizeable three-phase installation, with careful attention paid to system layout, wiring, and overall finish. The completed system impressed not only the homeowner, but also the electrician responsible for the three-phase upgrade, who described it as a 'top-quality installation'.

That level of care helps ensure the system is reliable, tidy, and ready for future upgrades as the homeowner’s energy needs evolve.

What the Customer Said

"Outstanding from start to finish! Always Off-Peak fitted a quite large three-phase system for us and were wonderfully helpful throughout. This was a huge contrast to the long gaps we experienced with the first installer we contacted. The team clearly enjoy what they do, and it shows in both their work ethic and attention to detail. Even the electrician who carried out our three-phase upgrade commented on the quality of the installation. Thank you again, we loved having you here!"

Fogstar Battery Storage for Modern Homes

This project shows how Fogstar 48V lithium batteries can support both energy security and cost savings when used as part of a properly designed home energy system.

Combined with proven Victron Energy equipment, professional installation, and room to expand with solar in the future, Fogstar battery storage gives homeowners greater control over how and when they use their power.

➡️ Find out more about Always Off Peak here