Sizing wizard
Size your home backup
Tell us how you live and what must stay on. We gate on physics first, then rank by days of runtime — not by who paid for placement.
Backup sizing
Size your home backup
Five questions. Honest matches — no upsell theater.
What kind of home?
Quick runtime check
Runtime Quick-Check
Pick a battery and an appliance — see days of runtime after the 0.85 inverter derate.
4.1 days
Formula: (6144 Wh × 0.85) ÷ 1.26 kWh/day = 4.1 days. Continuous draw ≈ 1.5 days at full load.
Lifetime cost per kWh-cycle
Cost per kWh-cycle (lifetime)
price ÷ (capacity × cycle life × 0.85 inverter efficiency)
| Unit | Price | $/kWh-cycle |
|---|---|---|
| FridgePower | $849 | $0.124 |
| Powerwall 3 | $15,000 | $0.131 |
| SOLIX F3000 | $1,399 | $0.134 |
| Explorer 5000 Plus | $2,879 | $0.168 |
| SOLIX F3800 | $1,699 | $0.174 |
| AC300 + B300K | $1,699 | $0.207 |
| DELTA Pro Ultra | $4,099 | $0.224 |
| DELTA Pro 3 | $3,199 | $0.230 |
| AC500 + B300S | $2,299 | $0.252 |
| Mesh Home Battery | $1,499 | $0.276 |
| Yeti Pro 4000 | $4,000 | $0.295 |
| SuperBase V6400 | $6,999 | $0.426 |