Plan reliable home backup
Battery Backup Calculator
Estimate battery-bank amp-hours from load, backup time and editable battery assumptions.
Smart result
Your battery estimate will appear here
—based on your details
We will turn the inputs into a clear answer, explain what drives it, and show what to do next.
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Frequently asked questions
What does Ah mean?+
Amp-hours describe battery charge capacity. Voltage and usable capacity are also needed to estimate stored energy.
Why is usable capacity adjustable?+
Battery chemistries and operating limits allow different depths of discharge. Use the product specification.
Will actual backup match exactly?+
No. Load changes, ageing, temperature, wiring and inverter efficiency affect real backup time.