Three Main Characteristics of a Rechargeable Battery

Regardless of the application, a secondary or rechargeable battery has the following three distinct characteristics  

The following terms are used to define the performance capabilities of batteries regardless of their applications  

Electrolyte A medium in which the flow of electrons is mediated by the migration of ions. 

Energy density. The amount of the electrical energy a battery stores per unit volume at a specific discharge rate. This is also known as volumetric energy density and is expressed in watt-hour per liter. 

Power density. The amount of power a battery can deliver per unit volume at a specified state of charge, which is typically is 20%. This quantity is also known as volumetric power density and is expressed in watts per liter. Specific energy. The amount of electrical energy a battery is able to store per unit mass at a specified state of charge. This is also known as the gravimetric energy density and is expressed in watt-hour per kilogram. 

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