A cell phone battery typically has a capacity of around 10 watt-hours (Wh). This isn't the wattage (power) it uses at any given moment, but rather the total energy it can store.
Understanding Watt-Hours (Wh) vs. Watts (W)
It's crucial to differentiate between watts (W) and watt-hours (Wh):
- Watts (W): This measures the rate of energy consumption or production. Think of it like the speed of a car. A phone might use 5W while gaming, but only 0.5W while idle.
- Watt-hours (Wh): This measures the total amount of energy stored. It's like the total distance a car can travel on a full tank of gas. A 10 Wh battery can power a 5W device for 2 hours (10 Wh / 5 W = 2 hours).
A phone's power usage fluctuates depending on its activity. For instance:
- Intensive tasks (gaming, video streaming): Can draw 5W or more.
- Idle or low-power usage: May only consume 0.5W or less.
The 10 Wh figure is an average. Actual capacity varies significantly depending on the phone model, battery size, and manufacturing variations.
Examples of Phone Battery Capacity:
- A typical smartphone might have a battery between 5 Wh and 20 Wh.
- Higher-end smartphones or those with larger screens often boast batteries with a higher Wh rating.
Why mAh is also used:
You'll often see phone batteries rated in milliampere-hours (mAh). This represents the battery's charge capacity at its nominal voltage (usually around 3.7V for lithium-ion batteries). The relationship is: *Wh = mAh V / 1000**.
