USB Phone World Posting Page
Thursday, June 10, 2010
Charging and discharging of li-ion laptop battery
Before slow charged with a constant pressure, li-ion laptop battery is fast charged with a constant current until the voltage reaches a certain value. Normally, there’s no device to monitor the process of constant-current charging. When it occurs to be charged with a large system load, the output current is low and vice versa. The current is determined by the remaining power of the ac adapter.
Appearantly, laptop battery is sharing the power with other components in the process of charging, such as CPU, hard disk, LCD screen and so on. If many other programs are running, the battery will be charging with the current varies in the number of smaller than nominal value, which is harmful to the battery. It is said in the specification of ibm thinkpad battery that try to avoid any operations when it is charging.
It is better to discharge in a normal condition. Any operation like some physical methods is dangerous to the laptop battery. If the protection circuit is out of work, the damage will be emerged in the whole battery or even explosion.
Generally speaking, the protection circuit of the battery is composed by surge block, control chip, fuse wire, temperature sensor, etc. As the wire is one-off, used to monitor the condition of the surge block, it will be burning out rapidly once any accident occurs in the charging process. Therefore, the interior circuit of the battery comes to be in off state and cannot revert anymore.
As to the battery correction, try to keep the current low when it is discharging. You can decrease the revolving speed of CPU, dim the screen and so on. Certainly, to keep the laptop in standby mode is a best choice.
In brief, it is better to maintain the laptop battery before repairing. One should take practical steps to achieve his aims. No matter it is damaged or not, just take the action to optimize the battery.
by: USB Phone World