In daily life, we often hear the two units mAh and Wh, which are both related to the capacity of the battery, but they represent different meanings. mAh (milliampere-hour) and Wh (watt-hour) are two different ways to measure battery energy, and understanding the difference between them is crucial for us to choose the right battery product.
mAh (milliampere-hour) is a unit of battery discharge capacity, which represents the product of the current intensity and time that the battery can continue to discharge under specific conditions. In simple terms, mAh tells us how long the battery can continue to discharge, but it does not directly tell us how much energy the battery can provide. For example, a 2000mAh battery can discharge for 2000 hours at a current of 1 mA, but can only discharge for 1 hour at a current of 2000 mA.
Wh (watt-hour) is a unit of energy, which represents the total energy stored in the battery. 1Wh is equal to the work done by 1 watt of power in 1 hour. Wh is a more direct measure of energy, which tells us how much energy the battery can provide, regardless of the discharge rate. Therefore, Wh is more suitable for comparing the energy capacity of different devices or different batteries.
Conversion between mAh and Wh
Although mAh and Wh are two different units, they can be converted between them by voltage (V). The formula is as follows:
Wh=mAh×V/1000
Here V is the nominal voltage of the battery. For example, a lithium battery with a nominal voltage of 3.7V and a capacity of 2000mAh has an energy of:
Wh=2000×3.7/1000=7.4Wh
Difference in practical applications
In daily use, the difference between mAh and Wh is reflected in different scenarios. For devices that need to work for a long time with low power consumption, such as remote controls or watches, mAh is a more intuitive indicator because it directly reflects the battery life. For devices that require high power output, such as laptops or mobile phones, Wh is more important because it tells us how much energy the battery can provide to support high power consumption operations.
mAh and Wh are two important parameters for measuring battery performance, which represent the discharge capacity and storage energy of the battery, respectively. Understanding the difference between them can help us better choose and use battery products. mAh is more suitable for describing the battery life, while Wh is more suitable for describing the total energy of the battery. In practical applications, we may need to pay attention to different parameters according to the needs of different devices. Through the above conversion formula, we can easily convert between mAh and Wh to adapt to different needs and scenarios.