1. Battery powered

The output of the battery is pure DC, which is very clean. The voltage of the battery is neither possible nor needs to be designed very high. The chemical characteristics of lithium batteries determine that the output voltage of a single cell can only be around 3.6V. Therefore, many batteries use a three-level series connection method, and 10.8V has become a popular battery voltage. Some batteries have nominal values slightly larger than integer multiples of 3.6V, such as 3.7V or 11.2V, in order to protect the battery.

2. Power supply

The situation is more complicated. Firstly, it is necessary to further stabilize and filter the added voltage to ensure stable operation in the event of poor power performance. The stabilized voltage is divided into two parts, one supplying power to the laptop and the other charging the battery. The part supplying power to the laptop is the same as when supplying power to the battery, while the part charging the battery needs to be added to the battery cell through the charging control circuit of the battery, The control circuit can be very complex, so the power supply voltage must be greater than the cell voltage in order to have sufficient capacity to supply the various units of the charging control circuit. The actual voltage applied to the battery cell will never be the nominal voltage of your power supply. Don't worry.

A suitable power adapter requires safety certification, which can protect personal safety. To prevent hazards such as electric shock and fire.