What Size Solar Battery Do I Need for My Home?
For home backup, battery size depends on which loads you want to run, how long you need backup, and how much solar or grid support you expect. A planning estimate for a house battery is usually more useful than a one-size-fits-all number.
Short answer: many homes start around 10-15 kWh usable capacity for basic backup, then scale up for longer outages or whole-home coverage.
What Changes the Battery Size?
- Essential loads: refrigerator, lights, Wi-Fi, and outlets use far less than HVAC.
- Backup duration: one night is very different from a multi-day outage.
- Battery chemistry: usable capacity and depth of discharge differ by product.
- Goal: backup-only, bill savings, or both.
Best Next Step
Use the Battery Sizing calculator to get a planning estimate, then compare the solar system size with Panel Count and Savings.
Next step: size the battery around your real backup needs.