The article comes from http://www.mylaptopbattery.co.uk/blog/2009/08/30/the-misunderstanding-of-laptop-battery-repeatedly-charge-and-discharge-deeply/
Notebook computers equipped with original equipment batteries, after a period of time after use, there will inevitably be of standby time. Some users said: “The depth with repeated charge and discharge method, you can restore the performance of the DELL laptop battery, thereby extending battery life,” I think this to be relatively one-sided.
To understand this issue correctly, may start with the battery type used in laptop computers start with. As you know, before 1995 the production of notebook computers are basically nickel-cadmium batteries to power. The battery is in use, if the charge-discharge method is not correct, the battery will have a “memory effect”, thereby reducing the battery’s actual capacity to eliminate this “memory effect” is used repeatedly in the best way to charge and discharge depth way. With the emergence of nickel-metal hydride batteries, battery capacity has significantly improved, but the “memory effect” did not completely eliminate the shortcomings.
In recent years, lithium-ion batteries in notebook computers has been rapidly growing popularity, due to lithium-ion batteries have basically eliminated the “memory effect” problem, it is used repeatedly to restore the battery depth of charge and discharge performance of the method no longer applies. However, lithium-ion batteries why I still appear to reduce the capacity of the problem? The root causes of that situation, is used in notebook computers and the original lithium-ion battery built-in battery management system in the making.
Battery Management: At present, in notebook computers, almost all adopted the “battery management” and “charge-discharge control” two kinds of chip-level management system. The “battery management chip” placed in a notebook inside the chip to store the register of the computer used in the capacity of lithium-ion batteries, working temperature, ID, serial number, charge and discharge status, charging and discharging the accumulated frequency of important information. The data information in the use of the process, according to the actual situation of continuously updated. The battery built-in “charge-discharge control chip,” the most important role is to monitor and control the battery charge-discharge process as a whole and be documented dell C1295 battery,dell GD761 battery,dell TD347 battery.
Charge: Lithium-ion battery charging process of the whole, divided into “fast charge constant-current” and “constant-voltage charging current decreasing,” two phases. The so-called “constant-current fast-charge” means a charge has just begun when the charge current is fixed and the charge voltage to follow the battery terminal voltage gradually increased until it reaches the nominal voltage charging. When the battery terminal voltage has reached the standard value, the control chip will be automatically transferred to the “Constant current charge decreasing” phase, this time charging voltage will no longer continue to rise, while the charge current is to follow the battery capacity is rising gradually decreasing and finally reached zero, and so will complete the entire battery charging process.
In the meantime, the process of charging the charge arising from voltage, current, time and other data curves will be recorded in the cell are known as “charge-discharge control chip” in memory. “Battery Management IC” is through the retrieval of these data, and is calculated by sampling data such as battery capacity, which is what we read in the Battery Information where the value of Wh.
Fixed: After repeated charging and discharging the battery after use, its built-in chip in the charging and discharging of data will of course change. If at this time “battery management chip” has no chance to re-read the newer, more complete data, it calculated battery capacity would of course not accurate, and to the user the impression that the battery capacity has decreased, but the reality on the battery capacity and there is no real reduction in the actual. Some brands of notebook computers comes with charging management software works, that is, the process of charging Refresh “charge-discharge control chip” in memory of the data, thus ensuring the “battery management chips,” the correctness of calculations.
If you take a close look over the use of laptop computers instructions, you will find among them the “computer in use one month later, the battery should be to make a full charge and discharge operation” instructions. Its main purpose is to use the depth of charge and discharge a way to modify the charge and discharge control chip registers inside the curve data, so that the battery charge control and the nominal capacity and the actual situation of the battery corresponds to arrive at the correct battery capacity values dell HD438 battery,dell KD186 battery,dell GD761 battery,dell Y9943 battery.