Terms of use

Last updated: October 19, 2026. By using WattLong, you agree to these terms.

Estimates only

Every calculator, chart, and runtime figure on WattLong is an estimate for planning purposes, produced from manufacturer-published specifications and the stated assumptions on our how we calculate page. Real-world results vary with appliance condition, temperature, battery age, wiring, and how a load actually behaves. Verify any figure you intend to rely on with the manufacturer and, where home wiring or a transfer switch is involved, a licensed electrician. Never exceed a product's published ratings, and follow the manufacturer's manual for the product you own.

Not professional advice

WattLong is an information and calculator site. Nothing here is electrical, engineering, medical, or safety advice. In particular, the CPAP runtime tool performs device-runtime arithmetic only; it makes no health claims and is not a recommendation about any medical device or therapy. Sizing a generator or battery system that connects to a home's wiring is work for a licensed electrician.

Accuracy and corrections

We source specifications from manufacturers and wattage figures from Generac and Home Depot publications, and we grade and date them. Products change; errors happen. We correct verified errors and record them on our corrections log. To the maximum extent permitted by law, WattLong provides this site "as is" without warranties of any kind, and is not liable for losses arising from reliance on an estimate.

Intellectual property

Site content is © WattLong. Product names (EcoFlow, Bluetti, Jackery, Anker SOLIX, Goal Zero, Generac, and others) are trademarks of their respective owners; WattLong is not affiliated with or endorsed by them. Specifications remain the property of their publishers and are used here for identification and calculation.

Links and affiliates

Outbound links, including affiliate links (see our affiliate disclosure), lead to third-party sites we do not control; their content and policies are their own.

Changes

We may update these terms; the date above will change when we do. Continued use of the site after a change constitutes acceptance.