PowerRuntime is a practical, brand-neutral library of battery, UPS, solar, generator and appliance calculators. Its purpose is simple: help people estimate whether a backup-power setup can start their equipment and how long it may realistically operate.
Why PowerRuntime exists
Battery runtime is often presented as capacity divided by watts. That shortcut ignores the losses and operating limits that cause real systems to behave differently. PowerRuntime separates stored energy from delivered power and asks for the inputs that materially affect the answer: usable battery percentage, conversion efficiency, inverter idle consumption, battery health, reserve, startup surge, appliance cycling and system ratings.
What the calculators check
- Continuous appliance load against inverter, UPS or generator running output.
- Motor and compressor startup demand against surge output.
- Battery voltage and amp-hours converted into watt-hours.
- Depth of discharge, state of charge, battery health and reserve capacity.
- AC conversion losses and equipment idle consumption.
- Refrigerator daily energy or compressor duty cycle.
- UPS watt and VA limits, power factor and high-discharge losses.
- Solar controller, battery-current and active-load bottlenecks.
How results should be used
Every result is a planning estimate, not a product guarantee or electrical design. Battery age, temperature, wiring, waveform, firmware, changing loads and manufacturer protection settings can alter actual performance. For important equipment, calculate first and then perform a supervised real-world test with a reasonable safety margin.
The calculation methodology explains the core formulas and compatibility checks. The calculator disclaimer explains important safety and accuracy limits.
Editorial approach
PowerRuntime aims to publish transparent formulas, practical assumptions and worked examples rather than hiding the calculation behind a single result. Articles are organized around the questions users ask before buying or operating backup power: appliance watts, battery size, startup surge, recharge time, fuel use and expected runtime.
Content may be corrected as product specifications, standards and available evidence change. When possible, readers should prefer manufacturer documentation and measured power data over generic appliance estimates.
Privacy and independence
Calculator inputs are processed in the browser and are not intentionally submitted to PowerRuntime unless a feature clearly states otherwise. The site is not tied to one power-station, battery, UPS or generator brand. Product references are educational and do not imply endorsement. Advertising does not influence calculator formulas, results, editorial conclusions, or the inclusion of a product or brand.
Questions or corrections
If a calculator behaves unexpectedly, include the page URL, the values entered, the result shown and the result expected. Use the contact page for correction guidance.