Calculate battery pack mass and volume from energy and entered pack-level density specifications, or find gravimetric and volumetric density from a measured pack. Select the task, enter the required values and select Calculate. Optional volume inputs may be left blank.

Use energy, mass and optional volume for the same complete battery pack.

Use rated or usable energy consistently with the density specification.

Include the casing, cooling and other pack components.

Pack volume (optional)

Blank omits volumetric energy density.

Battery Energy Density Formula

The following formula is used to calculate the Battery Energy Density. 

BED = ES / W
  • Where BED is the Battery Energy Density (kWh/kg)
  • ES is the total energy storage (kWh) 
  • W is the total weight (kg) 

To calculate the battery energy density, divide the total energy by the total weight.

How to Calculate Battery Energy Density?

The following arithmetic examples illustrate battery energy density; the values are hypothetical, not specifications for a commercial battery.

Example Problem #1:

  1. First, determine the total energy storage (kWh).
    1. The total energy storage (kWh) is given as: 150.
  2. Next, determine the total weight (kg).
    1. The total weight (kg) is provided as: 3.
  3. Finally, calculate the Battery Energy Density using the equation above: 

BED = ES / W

The values given above are inserted into the equation below:

BED = 150 / 3 = 50 kWh/kg = 50,000 Wh/kg. The calculator leads with Wh/kg and also reports kWh/kg.

Example Problem #2: 

For this problem, the variables needed are provided below:

total energy storage (kWh) = 75

total weight (kg) = 14

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer. 

BED = ES / W = ?