Calculate battery capacity in watt-hours, kilowatt-hours, amp-hours, usable energy, runtime, and number of batteries needed. This calculator works for solar batteries, RV batteries, backup batteries, off-grid batteries, lithium batteries, AGM batteries, and general battery planning.
Capacity:
The calculator converts volts and amp-hours into watt-hours and kilowatt-hours.
Usable energy:
Depth of discharge and system efficiency are applied to estimate usable battery capacity.
Runtime:
Usable watt-hours are divided by load watts to estimate how long the battery can run the load.
A battery capacity calculator helps estimate battery size for solar storage, backup power, RV systems, boats, cabins, UPS systems, and off-grid electrical loads.
It can help compare batteries by amp-hours, watt-hours, kWh, voltage, usable capacity, runtime, cost per kWh, and number of batteries needed.
Your result shows battery watt-hours, battery kWh, amp-hours, total battery bank capacity, usable kWh, usable watt-hours, runtime, batteries needed, series voltage, parallel amp-hours, cost per usable kWh, and detailed load totals.
Multiply battery voltage by amp-hours to get watt-hours. Divide watt-hours by 1,000 to get kilowatt-hours.
Amp-hours measure current over time. Watt-hours measure actual energy. Kilowatt-hours are watt-hours divided by 1,000.
Convert battery capacity to usable watt-hours, then divide by the load watts.
Usable capacity is lower because of depth of discharge limits, inverter losses, battery age, temperature, and manufacturer operating limits.