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How Home Batteries Work

A home battery is a box of rechargeable cells, a battery management system, and an inverter. It stores electricity and gives it back when you want it.

Charging And Discharging

A battery can charge from rooftop solar, from the grid, or both. It discharges to your home when the grid is down, or on a schedule you set to avoid expensive hours.

What Happens In An Outage

Most systems disconnect from the grid, then power a backup panel with the circuits you picked. Switchover speed varies by product. Ask any installer how fast the switch is and which circuits are included.

Key Terms

• Capacity (kWh): how much energy it holds. Usable capacity is the number that matters.
• Power (kW): how much it can deliver at once. This limits what you can run together.
• Backup panel: a subpanel with the circuits the battery supports.
• Round trip efficiency: the share of stored energy you get back.

What A Battery Cannot Do

It does not make power. Without solar or a generator, it runs down and needs the grid to refill. It will not run everything in a large house for days.