How Zaron Energy calculates backup power.
Our planning tools separate power from energy and make the assumptions behind each estimate visible.
The core calculation
Power is measured in watts (W) or kilowatts (kW). Energy is measured in watt-hours (Wh) or kilowatt-hours (kWh). They are not interchangeable.
Raw kWh = raw Wh ÷ 1,000. For planning tools, recommended battery capacity = raw kWh ÷ 0.90 × 1.20.
Why 90% efficiency?
Battery and inverter systems have conversion losses. We use 90% as a planning assumption, not as a specification for every product.
Why a 20% margin?
The additional planning margin allows room for variation in real-world use. It is an assumption, not a guarantee of runtime.
Surge and startup power
Some motors and compressors can require more power at startup than during steady operation. Zaron Energy does not invent startup values when a reliable specification is unavailable. For compatibility decisions, verify the appliance and power-system manufacturer specifications.
Runtime is not always duty cycle
Refrigerators, freezers and other cycling appliances do not necessarily draw their rated running power continuously. Where an estimate uses equivalent runtime or duty-cycle assumptions, we identify them as assumptions.
Planning, not electrical installation advice
Our calculators are intended for energy planning and product comparison. Whole-home systems, transfer equipment, 240V loads and permanently installed electrical equipment should be evaluated and installed by qualified professionals under applicable codes and manufacturer instructions.