This category of measurement units is defined by the "voltage" type, which is an SI derived quantity.
The SI derived unit for voltage is the volt.
The volt (symbol: V) is the SI derived unit of electric potential difference or electromotive force, commonly known as voltage. It is named in honor of the Lombard physicist Alessandro Volta (1745–1827), who invented the voltaic pile, the first chemical battery. The volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power. Hence, it is the base SI representation m2 · kg · s-3 · A-1, which can be equally represented as one joule of energy per coulomb of charge, J/C.