Watt Hours vs Amp Hours


Power tools are often rated in ampere-hours (Ah) to indicate the capacity of the battery and its ability to deliver power over time. For example, a typical construction battery that has 72V 6Ah - means that the battery can deliver a current of 6 amperes for one hour at a voltage of 72 volts. This rating gives users an idea of how long the battery can power the tool before recharging. It's a useful metric for comparing the run time of different power tools or different batteries for the same tool.

Ampere-hours (Ah) is a unit of measurement used to describe the energy capacity of a battery. One ampere-hour is the amount of electric charge transferred by a steady current of one ampere for one hour; and Watt-hours (Wh) is a unit of measurement used to describe the total amount of energy that a battery can store or that an electrical device can use over time.

For example: 18V 6Ah to Wh
The formula for calculating watt-hours is:
Watt-hours (Wh) = Voltage (V) × Ampere-hours (Ah)
108 Wh = 18 V x  6 Ah

On the other hand, to convert watt-hours (Wh) to ampere-hours (Ah) :
Ampere-hours (Ah) = Watt-hours (Wh) / Voltage (V)
2 Ah = 108 Wh /  54 V

When it comes to measuring how much juice a battery has, Watt-Hours (Wh) is the way to go. It's like the all-in-one measure that looks at both voltage and current, giving you a clear picture of how much power your battery can deliver. Unlike Amp-Hours (Ah), which can be influenced by voltage variations, Watt-Hours provide a comprehensive and standardized measure of energy, factoring in both voltage and current.

Watt-hours offer a more accurate representation of stored energy, especially in fluctuating voltage scenarios. They simplify decision-making by directly correlating with device power consumption over time. In conclusion, Watt-Hours goes beyond technicalities, ensuring accurate and practical energy measurements in diverse applications.

The Wacker Neuson BOB14 with 1425 watt-hours (Wh) provides a total energy storage capacity measurement, considering both voltage and capacity.