Notebook computer batteries are generally composed of casing, battery pack, charge and discharge control and protection circuits (to prevent overcharging and overdischarging).
Let me talk about the battery pack, which is the core component of the laptop battery. Generally, laptop battery cell use 10.8V or 11.1V, and a single battery cannot meet the requirements. Therefore, laptop batteries are battery packs composed of multiple single cells in series and parallel (as shown in the figure, two groups of 3 are connected in series and connected in parallel. Battery pack). As for the 3300mAh, 4400mAh, etc. that you often see in the battery shell, it refers to the battery capacity. It indicates that the current can be used for one hour when discharging the battery. For example: a 4400mAh lithium battery can be discharged at a current of 4400mA for one hour . So the larger the value, the better proof that it can work for longer.