Calculator
Battery bank size for your daily load
Size the battery bank (Ah) needed to cover a daily energy use for a chosen number of backup days, accounting for usable depth of discharge, round-trip efficiency and temperature.
Related calculators
How many days your battery bank lasts
Usable capacity after depth-of-discharge
Series / parallel wiring configuration
Estimates for planning only. Verify with a meter and follow NEC / local code; have a licensed installer confirm any system before purchase or wiring. See the methodology for formulas and sources.