4.1.1 Laptop battery structure
1) Actually, the internal structure of laptop battery is composed of a shell, a working circuitry and a battery group.
2) The core part of a laptop battery is the battery group. Generally, laptop battery uses 10.8V or 11.1V, while a single battery could not satisfy the requirement, so laptop batteries are all battery group composed by many single battery cells connected in series parallel. You may often see the marks 3300mAh, 4400mAh on the shell of battery, which mean the capacity of the battery. It indicates that the battery could hold for an hour when discharge, for example: 4400mAh lithium battery could discharge an hour in 4400mAh current. So the large the value is, the longer it could work.
3) Charge/Discharge control and protection circuitry, just as its name implies, it takes charge for battery’s charging/discharging control and protection. Here’s the work principle: during the process that lithium battery is charging and almost to full, the voltage would drop a little, so when control circuitry inspects the situation, it would think the battery is full. And the protection circuitry’s work is to cut off power to prevent over charging; when discharging, battery’s voltage is stable basically, and it would drop suddenly only when the left power is little. And when control circuitry inspects the situation, it would think that the battery power has run out and go to inform the protection circuitry to cut off power, in case the battery over discharges that may shorten the bat