You determine the right size battery backup by listing the loads you need to keep running during an outage (essentials vs. whole-home), totaling their daily kilowatt-hour usage, and matching that to a battery system that delivers that energy with some buffer. Most Spokane-area homes need 13.5–27 kWh for essentials only, and 30–50+ kWh for whole-home backup.
Sizing factors
- Essential loads (refrigerator, freezer, well pump, key lights, internet, medical)
- HVAC requirement during outage
- EV charging during outage (often skipped)
- Days of autonomy desired (typically 1–2 days)
- Solar pairing for daily recharge
We perform a full load analysis before recommending battery capacity, then integrate with solar and the panel. See our home battery backup service.
