Sizing a home battery for load-shedding, not just backup

When people shop for a home battery, they usually start with the kWh number on the spec sheet. That’s the wrong starting point.

What actually determines whether a battery gets you through an outage is peak daily outage length, not total capacity. Start by logging your longest load-shedding stretch over a typical month, then size around that number with headroom — not around the biggest battery you can afford.

A correctly sized 5kWh battery that covers your real outage pattern beats an oversized 15kWh unit that still leaves you short during the worst week of the year.