Nominal battery capacity

The capacity of a battery in Wh (watt-hours) indicates how much total energy that battery can store and deliver. While the nominal voltage tells us “at what voltage it works”, Wh tells us “how much energy it has inside”. It is a more useful way to compare range and autonomy than only looking at ampere-hours, because it takes into account both voltage and capacity. For example, a 36 V and 10 Ah battery has an approximate capacity of 360 Wh, because:

Wh = V × Ah

This means that, in theory, it could deliver 360 watts for one hour, or 180 watts for two hours, although in practice this depends on real usage, temperature, and system efficiency. That is why in electric scooters, electric bicycles, or any electric vehicle, Wh helps to better understand the real autonomy that the battery can provide.