Battery Calculators

Home Energy Desk tools

Battery Calculators

Estimate battery runtime, charging time, current, usable energy, capacity conversions, expansion, degradation, and payback.

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Battery Backup Runtime Calculator

Estimate usable battery energy and backup time from capacity, state of charge, reserve level, load, and inverter efficiency.

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Battery Charging Time Calculator

Estimate input energy and charging duration for a home battery between two state-of-charge levels.

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kWh to Ah Calculator

Convert battery energy in kilowatt-hours to amp-hours at a selected nominal voltage and conversion efficiency.

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Ah to kWh Calculator

Convert amp-hour capacity to nominal and usable kilowatt-hours using battery voltage, usable capacity, and system efficiency.

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Battery Bank Series and Parallel Calculator

Calculate total voltage, amp-hour capacity, energy, and unit count for batteries connected in series and parallel.

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Battery Current Calculator

Estimate DC battery current required to supply a given AC or DC power load at a selected battery voltage and conversion efficiency.

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Usable Battery Capacity Calculator

Estimate the energy available between current state of charge and a selected minimum reserve, after efficiency losses.

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Battery Depth of Discharge Calculator

Calculate depth of discharge, remaining state of charge, and energy used during a battery cycle.

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Battery Expansion Calculator

Estimate combined capacity and backup runtime after adding compatible battery modules to an existing system.

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Battery Degradation Calculator

Estimate retained capacity, total degradation, and average annual capacity loss from original and currently measured capacity.

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Home Battery Payback Calculator

Estimate simple payback and multi-year net benefit for a home battery using installed cost, incentives, bill savings, and annual costs.

Planning with batteries calculators

Use several related tools rather than relying on one result. Energy systems are constrained by both energy and power, and final equipment choices depend on climate, operating schedules, manufacturer limits, utility rules, and local codes.