Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

Usable Watt Hours (Wh)

Required number input.

Pack Mass Kilograms (kg)

Required number input.

Gravimetric battery energy density from usable watt-hours divided by battery pack mass in kilograms. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Watt Hours Per Kilogram (Wh/kg)

The resulting watt hours per kilogram returned as a number.

• Battery voltage, capacity, resistance, state of charge, and energy density depend on chemistry, series-parallel topology, temperature, rate, cutoff, balance, aging, and measurement method. Cell mismatch and protection limits must be evaluated separately.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Battery Parallel Capacity

  Nominal parallel pack amp-hour capacity from identical branch capacity and integer branch count.

• Battery Series Voltage

  Nominal series battery pack voltage from identical cell voltage and integer cell count.

• Energy kWh

  Energy consumed in kilowatt-hours from constant power and elapsed hours.