For a battery, refers to the quantity of energy able to be stored and restored during the operation of the equipment.
Useful to know:
is a physical concept used to measure the energy able to be stored in a material or a device: this can be a battery or a superconductor, but also a liquid fuel such as petrol or a solid fuel such as coal, or even a radioactive element such as tritium, uranium or plutonium...
is expressed by unit of mass or based on volume.
We distinguish between the following:
· mass expressed in Wh/kg ;
· volumetric usually measured in J/m3: this indicator is more suited to fuels such as hydrocarbons.
For batteries, is usually given as a function of mass, that is to say in .
The of batteries depends on the technology used.
Depending on the components and electrochemical reactions in question, we talk about lead, nickel-cadmium (NiCd), nickel-metal hydride (), lithium-ion (), lithium-polymer (Li-Pol), sodium-sulfur (Na-S) batteries...
Depending on their , batteries can serve the operation of different devices, or be allocated to different uses: mobile phones and laptops, cameras, portable tools, light electric or electric road vehicles...
In this area, technologies are constantly evolving to provide the best possible autonomy.
With of 0.027 7 kWh/kg, lead batteries are able to start a combustion engine vehicle.
Electric vehicles usually use lithium-ion () accumulator batteries which have a much higher : around 0.2 kWh/kg.