Solar & battery sizing calculator

Tell us what you want to run and for how long. We size the battery bank, solar array, charge controller, and inverter for an off-grid or backup system. Estimates only, real sizing depends on your loads and climate.

Your needs

Daily energy use (kWh)

Typical: fridge + lights + electronics ~3-5, small home ~8-15, full home ~20-40.

Days of backup (autonomy) Peak sun hours per day

US average is roughly 3.5 to 5.5 depending on region and season.

System voltage Largest simultaneous load (W)

Add up what might run at once (AC, microwave, well pump, etc.).

Recommended system

Usable battery storage

Battery bank (total)

Battery capacity

Solar array

Charge controller

Inverter (continuous)

Assumes LiFePO4 batteries (90% depth of discharge) and ~75% system efficiency. A starting point, not a final design. For grid-tied or permitted work, consult a licensed electrician.

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