When you move to solar, the battery bank is the component that decides whether the lights stay on after sunset. Unlike a grid-tied setup where the utility is your infinite store, an off-grid or hybrid system leans entirely on battery capacity once the sun is down.
Understanding your load profile
Before sizing anything, measure how much energy you actually use. A typical 3-bedroom home in our service area draws between 10 kWh and 15 kWh a day with energy-efficient appliances.
- Lighting: LED bulbs throughout (~500W, 6 hrs/day) ≈ 3 kWh/day
- Refrigeration: a modern inverter fridge ≈ 1.5 kWh/day
- Cooling: a 1HP inverter AC (8 hrs at night) ≈ 6 kWh/day
- Entertainment & work: TVs, laptops, routers ≈ 1.5 kWh/day
The biggest mistake homeowners make is sizing the battery from their panel output instead of their actual nightly consumption.
Calculating required capacity
If your nightly load is 10 kWh you might assume a 10 kWh battery is enough. But you must account for Depth of Discharge (DoD). LiFePO4 cells can safely reach 90%, yet designing for 80% maximises lifespan: 10 kWh ÷ 0.8 = 12.5 kWh of usable capacity.
Days of autonomy
Autonomy is how long the bank can run with no sun to recharge it. With the grid as backup, one day is usually plenty. Fully off-grid in a rainy region, double it to two days.
Our recommendation
For a standard 3-bedroom home with one night-time AC, start at 10–15 kWh of LiFePO4 storage. Our modular wall-mounted units let you stack a second in parallel as your needs grow.