SolarBatteryBankCalc
Worked example

Solar & battery sizing for a whole-home backup

Backup for essential circuits during outages — fridge, freezer, lights, internet and a few outlets — sized for one to two days without grid or sun.

Open this whole-home backup setup in the calculator →

Example daily load

DevicePowerUseEnergy
Fridge150 W24 h/day3600 Wh
Chest freezer100 W24 h/day2400 Wh
LED lights100 W5 h/day500 Wh
Wi-Fi router12 W24 h/day288 Wh
TV90 W3 h/day270 Wh
Total7058 Wh/day

Sized system (LiFePO4, 48V, 2 days autonomy)

Battery bank
19.98 kWh
Capacity
416 Ah @ 48V
Solar array
2273 W
Sun hours assumed
4.5 h/day

Open this setup in the calculator — then adjust for your own devices →

Notes for a whole-home backup

These figures assume 4.5 peak sun hours and 2 day(s) of autonomy. If your location is cloudier, your usage is higher, or you want more buffer, increase autonomy or array size. The button above opens the full calculator pre-loaded with this whole-home backup setup, so you can change any device, voltage or chemistry and see the system resize instantly — the example is a starting point, not a prescription.