4000mAh

4000mAh refers to a battery capacity rating. The 'mAh' stands for milliampere-hour, a unit of electric charge. It quantifies how much current a battery can supply over a specific period. In simpler terms, a higher mAh rating generally indicates a battery that can store more energy and, consequently, power a device for a longer duration before needing to be recharged.

A 4000mAh battery means that, under ideal conditions, it could theoretically supply a current of 4000 milliamperes (or 4 amperes) for one hour, or 400 milliamperes for ten hours, and so on. The actual usage time will vary significantly based on the device's power consumption, screen brightness, network signal strength, and the types of applications running.

This capacity is commonly found in portable electronic devices such as smartphones, tablets, portable power banks, and some wireless earbuds. For a smartphone, a 4000mAh battery is often considered a mid-range to high-capacity option, capable of providing a full day of moderate to heavy use for many users. When comparing devices, battery capacity is a key specification to consider for understanding potential battery life. However, it is not the sole determinant, as power efficiency of the device's components also plays a crucial role.