Disclaimer
Please read this before relying on any result.
By Zubair Abid. Updated .
Results are estimates
The calculators use standard formulas and realistic assumptions, explained on how we calculate. Real results depend on your specific devices, battery age and health, temperature, wiring and usage, and can be noticeably lower than the estimate.
Safety-critical uses
Don't rely on these estimates alone for medical equipment (such as CPAP machines or oxygen concentrators), safety systems or any situation where losing power could cause harm. Follow the manufacturer's guidance and keep a backup plan.
Electrical installations, including home solar, inverter and battery systems, should be designed and installed by a qualified electrician in line with local regulations.
Travel rules
Airline and security rules for batteries change and vary by airline and country. The airline checker reflects widely used thresholds, but your airline has the final say. Always confirm before you travel.
Advertising and affiliate links
The site is funded by advertising. Some pages may include affiliate links; if you buy through them, the site may earn a commission at no extra cost to you. This never changes a calculation.