SunSavvy

Solar Battery Size Calculator

Work out how much battery storage you need to keep your essentials running during an outage.

A typical home uses ~30 kWh/day total; essentials (fridge, lights, wifi, some outlets) are often ~8–12 kWh/day. Usable capacity is assumed at 90%.

Usable energy needed
10 kWh
Battery capacity (nameplate)
11.1 kWh
Battery units needed
1
at 13.5 kWh each
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Do you even need a battery?

A battery is most worth it for backup power or weak net metering — not every home needs one. Read are solar batteries worth it? before you buy, and remember standard grid-tied solar shuts off in an outage unless it's set up for backup.

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Compare local installers — no obligation.

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