» Electrical » Battery Energy Density Calculator The Battery Energy Density Calculator provides crucial metrics for battery manufacturers, designers, and end-users by calculating the gravimetric (Wh/kg) and volumetric (Wh/L) energy density of batteries.
The battery’s voltage, charge capacity and discharge capacity determine its energy density. According to what we explained in the lifepo4 charge voltage guide the higher the voltage and discharge capacity, the more power you’ll get out of your battery — but this also makes it heavier and larger in size.
The method for calculating a battery’s specific energy or energy density is as follows: Nominal Battery Voltage (V) x Rated Battery Capacity (Ah) / Battery Weight (kg). It’s possible to calculate the specific energy of an individual cell, but the calculation requires knowledge of the actual cell dimensions and geometry.
Higher energy densities mean a battery can store more energy relative to its size and weight, which is crucial for enhancing the performance and portability of devices. Can the energy density of a battery change over time?
Wikipedia cites it may be around 100–265 Wh/kg, although it refers to it as "specific energy" and uses "energy density" to refer to a measurement based on physical volume. I'm thinking of buying a lithium-ion battery pack rated for 12V @ 6800mAh, giving it 81.6 Wh, and it weights 162 grams, meaning its energy density is 503.70 Wh/kg.
[Nominal battery Voltage (V) x Rated Battery capacity (Ah)] x DOD/ Battery Weight (Kg) Nominal Battery Voltage (V) x Rated Battery Capacity (Ah) / Battery Weight (kg) = Specific Energy or Energy Density (Wh / kg)