Which of the following describes the role of battery capacity measured in ampere-hours?

The role of battery capacity measured in ampere-hours is primarily to quantify how much current a battery can deliver over time. This measurement helps in determining the duration for which a battery can supply a given load before needing to be recharged. For example, if a battery has a capacity of 10 ampere-hours, it can theoretically supply 10 amperes of current for one hour, or 1 ampere for 10 hours. This relationship between current and time is crucial for understanding how long a battery will last in different applications, making this measurement fundamental for both consumer and industrial applications.

Voltage output relates to the energy stored in a battery, but it is distinct from capacity, which focuses solely on the amount of current supplied over a given period. While the size and weight of a battery may correlate with its capacity to some degree, they do not directly define its performance in terms of how much current can be delivered over time. Thus, ampere-hours is a critical specification for evaluating and comparing battery performance, especially when planning for specific usage scenarios.