About Backup Power Math

Backup Power Math is published by Aliva Digital. It exists to help people work out how much backup power they need before they shop, using plain arithmetic they can check.

How the calculators work

The rules are simple and visible. Daily energy is watts times quantity times hours, divided by 1,000. The battery size is that energy times outage days, divided by the depth of discharge and inverter efficiency. Every setting is stated on the page, and appliance watts can be edited. The calculators do not save or send what you type.

Where product specs come from

Product figures come from each manufacturer’s own product or documentation page. Each product record keeps the page address and the date it was checked. When a manufacturer does not publish a figure, we leave it blank and say so rather than guess. Prices and specs change, so confirm them on the manufacturer’s page before you buy.

How the site earns money

Some links to products and installer quote services are affiliate links. If you buy through one, Backup Power Math may earn a commission at no extra cost to you. The calculator results do not depend on whether a product has an affiliate link. We make no claims about bill reductions or break-even timelines, because those depend on facts we cannot know about your home and your utility.

What this site is not

Backup Power Math is not an engineering service or an electrician. A licensed electrician should confirm any panel, transfer switch or 240 V work. Nothing here is medical advice.

Contact

dan@alivadigital.com