What battery backup does
A battery backup system keeps selected circuits live when the grid goes down. Instead of a generator starting up in the driveway, a battery and inverter switch over in a fraction of a second, so your lights stay on and your Wi-Fi does not drop. During the day the battery can be charged from solar panels; at night, or on days with no solar, it charges from the grid when power is available.
Load-shedding is not the only reason people add storage. A battery also lets you use your own solar power in the evening, when household demand peaks, rather than only during the day.
How we size a battery
We start with the circuits you want to keep running. Typical essentials are lights, the fridge, Wi-Fi, a television and a few plug points. We add up the running load of those circuits, decide how many hours of backup you want, and size the battery to suit. If you want to run heavy loads such as a geyser, oven or pool pump, the battery and inverter need to be sized much larger, and we will say so honestly.
Battery capacity is measured in kilowatt-hours (kWh), and the inverter's continuous power output matters as much as the capacity. A battery that can store enough energy but cannot deliver enough power at once will trip when a large appliance starts. We match the two.
Battery types and what to expect
We install lithium (LiFePO4) batteries. They hold their capacity well over thousands of cycles, need no water top-ups, and can be mounted indoors or in a garage. Older lead-acid batteries are cheaper up front but do not last as long or cycle as deeply, so we rarely recommend them for new installations.
Grid-charged or solar-charged
You do not need solar panels to have battery backup. A battery charged from the grid will still carry you through load-shedding. If you add solar PV later, the battery charges from the sun instead, and your bill drops further. Most hybrid systems use an inverter that manages both the panels and the battery.
Who it is for
Households tired of resetting clocks and losing food. Home offices and small businesses that cannot afford downtime. Complexes and body corporates that want to keep common-area lighting, gates and lifts running. Anyone weighing a battery against a generator and wanting something quieter, cleaner and automatic.
What affects the price
The battery capacity, the inverter size, whether solar panels are added, and the amount of electrical work needed to split essential circuits onto the backup supply. Prices change with battery technology and the rand, so we quote from current pricing.
Related pages
See load-shedding solutions for the bigger picture, read solar battery options in South Africa, or find us in the Northern Suburbs.
Questions
Frequently asked questions
How long will a battery run during load-shedding?
It depends on the battery size and what you keep running. A small battery can keep lights, Wi-Fi, a TV and a fridge going for a few hours. The exact runtime is calculated from your load in the quote.
Do I need solar panels to have battery backup?
No. A battery can be charged from the grid and still carry you through load-shedding. Adding solar panels later means the battery charges from the sun instead.
What type of battery do you install?
We install lithium (LiFePO4) batteries, which have a long cycle life and need little maintenance.
Can a battery run my whole house?
A battery can run your whole house if it and the inverter are sized for your total load. Most households start with essential circuits and expand later.