ampere-second vs charge unit

ampere-second and charge unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
ampere-second	Yes	No	No	No
charge unit	Yes	No	No	No

As nouns, charge unit is a hypernym of ampere-second; that is, charge unit is a word with a broader meaning than ampere-second:

ampere-second: a unit of electrical charge equal to the amount of charge transferred by a current of 1 ampere in 1 second
charge unit: a measure of the quantity of electricity (determined by the amount of an electric current and the time for which it flows)

Other hypernyms of ampere-second include quantity unit.

ampere-second (noun)	charge unit (noun)
a unit of electrical charge equal to the amount of charge transferred by a current of 1 ampere in 1 second	a measure of the quantity of electricity (determined by the amount of an electric current and the time for which it flows)