Laptop Power Management

soff

Laptop Power Management [Copy link]

Mobility is the most important feature of laptops. How to improve its flexibility and stability is the primary problem facing laptops . As the power supply part of laptops, it is the key link to ensure its effective operation. The power system of a laptop is the third most important component after the CPU , its motherboard, and the display. The power system includes power adapters, rechargeable batteries, and power management systems.

Considering the heat dissipation problem, the power adapter is independent of the laptop host. Generally, it is suitable for 100V-240V AC input, which converts AC into DC for the host to work. In addition, it also has the function of charging the battery in the machine. In order to prevent long-term charging from reducing the battery life, the machine is equipped with a detection circuit and a charging status indicator, and the charging circuit can be automatically cut off after the battery is fully charged. Therefore, the laptop has high requirements for power supply, and stability and anti-interference are the main indicators for testing power adapters. In order to avoid the ripple coefficient of the input power being too large or a sudden high current shock and burning the power adapter, try to connect it to a power socket with overload protection.

Once a power outage occurs, the battery will show its superiority. The portability of the laptop depends largely on the support of the battery. The battery is the heart of the entire power system, so it cannot be underestimated. The earliest laptops used nickel-hydrogen batteries. Although this type of battery also has a good cost-effectiveness and high power, the battery has a short continuous discharge time, so it was soon replaced by lithium-ion batteries. Lithium batteries have a large energy storage density, can be charged at any time, and have a long continuous discharge time, generally about 3 hours. While improving battery performance and increasing battery capacity, high-end notebook computers often improve the floppy drive structure to a smart slot. In addition to storage devices such as floppy drives, a second battery can be connected to double the battery capacity.

Laptops usually have three batteries. The first is the main battery. When the AC power is not connected, the main battery ensures the normal operation of the machine and charges the backup and real-time clock batteries. The main battery can generally provide power for 3.5 hours. The second is the backup battery, which ensures the power required for data and running program backup in the startup mode. The power supply time is about 1 hour. The third is the real-time clock battery, which provides power for the real-time clock and calendar inside the machine and maintains the system configuration data. It can work continuously for 1 month. As a senior agent of Toshiba notebook computers, Lenovo Group has made several suggestions to users on how to extend the service life of batteries.

First, if users have spare batteries, they should use them in turn to minimize excessive consumption of one battery. Second, when the notebook computer is not used for a long time, the battery must be removed from the machine to avoid damage to the notebook. Third, when the battery is fully charged, the AC input should be disconnected. Because overcharging can overheat the battery and shorten its life. Finally, do not charge the battery when it is too cold or too hot, because the appropriate temperature for charging is between 10-30 degrees Celsius.

Of course, while increasing the battery life of the laptop, you can also save the laptop's power consumption in other ways. The power supply time of the laptop depends not only on the battery life itself, but also on the power management of the machine. The better the battery power system is managed, the greater the return it will have in work. Laptops include the following common advanced power management functions:

Operation mode: The operation mode can control the processor speed or set a power saving timer.

Standby mode: When the user does not operate the machine for a short period of time, it can enter standby mode.

Suspend mode: When the user leaves the computer for a long time, it can enter suspend mode.

Hibernation mode: When the user leaves the office for a few days, the laptop can enter hibernation mode.

Let's take a Toshiba laptop as an example. It can be set in three modes. Its power supply modes are standard mode, power saving mode and full mode. Through the cyclic conversion of the three modes, the brightness of the display screen and the voltage and power consumption of each component are adjusted to meet the working needs in different environments.

Using power management programs to achieve power saving control is also a very effective and feasible method. Currently, Toshiba laptops have widely adopted this intelligent power saving management technology, which uses software methods to control the power consumption status of major power-consuming components, and reduce or even stop the power supply to components that are not working temporarily. For example, if the management program detects that the user has not used the keyboard for a certain period of time, it will automatically turn off the display screen background; if it detects that the hard disk is not in use, it will turn off the hard disk drive power supply, etc. In the ready-to-work state, the CPU clock stops, the display and hard disk drive power are cut off, and the power consumption can be reduced by more than 70% .

Of course, the power management function implemented by the current power system does not consider the working state of the system in most applications, but assumes that the system and system equipment are always available, which often causes some problems. How to solve these problems still requires the continuous efforts of notebook computer manufacturers and battery manufacturers.