Battery sizing guide
How Many Solar Batteries Does My Home Need?
Battery quantity should follow a load plan—not a guess.
The number of batteries a home needs cannot be determined from square footage alone. Useful sizing considers both energy capacity over time and the instantaneous power required to start and run appliances.
What determines the answer?
Energy is measured over time
Usable kilowatt-hours influence how long selected loads can operate before the battery reaches its reserve.
Power controls what can run
Continuous and surge output determine whether the system can support multiple appliances or high-startup loads at once.
Solar can extend runtime
During a daytime outage, compatible solar may serve loads and recharge storage, but production is weather dependent.
Frequently asked questions
Can electric bills size the battery?+
Bills provide useful monthly consumption data, but circuit-level priorities and peak loads are also needed for backup design.
Is more capacity always better?+
Not necessarily. Capacity should balance performance goals, available space, system limits, and budget.
Should I size for the worst possible outage?+
That is a personal resilience decision. Many homeowners prioritize essential loads and manage consumption during longer outages.