1. The appropriate charge and discharge currents.
(2) to minimize the discharge less than the charge or over discharge.
Although the battery is a consumable, lithium-ion battery is no exception. But no one wants to fine up the battery with the spirit of God, to age the look on finished and do not rattle, no one wants to start his own half dead battery does not pull the living, has been so on the edge of two or three years, good people sad how it taste, you say is not it?
Well, get down, following the battery began to speak. First to explain, only lithium-ion battery.
Appropriate charge and discharge current
General literature and national standards for lithium-ion batteries on said lithium-ion battery charge current should be between 0.2C to 1C. It is said that the charge current battery capacity, such as your battery is 4AH, then the 0.2C charge current is 0.2X4 = 0.8A, that is the charge current should be between 0.8 to 4A. In general, the charge current as small as possible within the permitted range, the start of lithium-ion battery is constant current charge, in my IBM R31, this current is 2.8A or so, the equivalent of 0.7C, is charging its own circuit control, can not set itself. Although this charge does not exceed the standard indicators, but it is relatively large, especially when the battery capacity decline for some time after the charge current may be more than 1C. Now laptop charging users regardless of the length of time has become the target of the manufacturers were forced to charge current set so high.
So first step is to reduce the charge current. I have friends working in the laboratory, a variety of equipment readily available, where his trial on a bit. Power output on the first string on a resistance to try, the result is to reduce the current, but became intermittent charge, this is not a good thing. After repeated trials, 4 Ohm is a more ideal value, this time around 0.8A charge current is very stable. This is just the current flowing through the machine power connector on the battery charge current is estimated to be larger, it should be slightly larger than 0.2C. Specific to a different machine, this value may be different. Also with the rise in battery voltage, charge current will be reduced, but reduced only slightly, less than 0.05A. In this charged state, charging circuit seems to work, the battery indicator does not light. So the battery voltage up to 12.6V, charging circuits came into play, the battery into the trickle charge state, this time does not matter whether the series resistance has been charging current is controlled by the charging circuit, the last full charge after the charging circuit automatically end. The charging time is about 5.5 hours, if not resistance, charging time is 3.5 hours.
Lithium-ion battery is very precious, good charge control circuit is required. In this charging method, can reduce the charge current, battery life, while use of the books the original charging circuit controls the charge, it is relatively easy to achieve, just buy a power plug (that is, from the power supply into the books kind, the best to buy two, followed by the methods mentioned also used one to good quality) and a resistor on it, pay attention to the larger resistance of the head, after all, about 2W of power above Otherwise, it would be more heat resistance, preferably in their own constant resistance wire a, wire resistance and this resistance almost independent of temperature. However, this disadvantage is also obvious, is not charged at the same time work with books. Another charge when there will be a strange phenomenon, I do not write omitted here, and you try to know, but fortunately this phenomenon into the trickle charge after the state disappeared. To extend the charging time is not a big problem, anyway, to start charging before going to sleep at night, wake up the next day on the charge well, of course, if you are a night owl or a special short sleep time, that is another matter.
Small current charging problem solved, and now the discharge problem. In fact, this is difficult, after all, the book is used to work, the discharge current will vary with the working state, the method mentioned here only designed to restore battery capacity of the operation.
Start the machine, set the power management never goes to sleep (standby) and hibernation (hibernate), others are set to the most power-saving modes, including CPU speed, turn off hard disks, turn off the monitor, etc., while in TP management process Close some unused hardware, such as sound cards, etc., and then open the battery status display window, let it run in the foreground! ! ! Close other programs, in particular, screen savers and other programs that run regularly! ! Do not use the machine, do not close the lid, let the battery discharge is completed (not to discharge the minimum value set to 0, I set a 3 percent). Display and hard drive off after the discharge current is about 0.5A, this is my IBM R31 can be achieved on the minimum discharge current, battery discharge to the lowest setting after the machine will automatically shut down. The discharge lasted about four hours, depending on your battery capacity may be different, this time the method is used to pass the sleep.
Well, finally stressed that the above method is not dead, especially the discharge, there are ten times can be the first to do so, otherwise the battery still doing? All the best with a small charging current charge, of course, if you need to use the battery, plugged in directly to the book on it.
I use this method of battery, charge and discharge is now 14 times the capacity has remained at more than 45, while the battery design capacity is 43.2, also declined during the time, but after such a charge and discharge are restored.
Beginning about two points, one appropriate charge and discharge, the second is not enough to charge and discharge, inadequate discharge following a look at how to solve the problem on the charge of it:
Minimize the discharge less than the charge or over discharge
In fact, over-discharge a good solution, not to terminate the discharge limits set too low on it, I have been using 3%.
Many times a battery may be just a short time, such as battery remaining 70%, if the power switch, then the battery will automatically charge, there is no such a cycle, although battery life is not the absolute number of cycles to be dead, but always it will reduce the battery capacity, lithium-ion battery is said there is no memory effect, but in fact nothing but a low memory effect. Unfortunately, IBM does not provide enough to solve the charge-discharge method, but provides a basis for solving this problem. This is what I found on the R31 may not necessarily suitable for other machines, but the method should also not far, do not forget after you tried to paste them all to share.
R31 charging circuit based on the status of the power to decide whether to charge the battery. Power output voltage is 16V, the error of plus or minus 0.2V, if the voltage is below 15.5V, then the charging circuit is not charging the battery, while the books still work, which is IBM provides the basis to solve the problem. But this foundation is weak, because if the voltage is lower than 15.2V, books will be converted to battery power, even when the power plug in the books is useless. In other words, we can toss the space is 0.3V.
If you can find a 15.5V, over current 3A switching power supply, then the problem is solved, otherwise please read on.
Reduce the power output voltage 0.5V is not an easy thing, series resistance is not enough, because the voltage across the resistor will change with the current size. I use the diode rectifier, required to allow through the current 2A above, otherwise the pipe is too hot. Rectifier diode forward voltage drop between 0.7 to 0.5V, just to meet the requirements. Now plenty of such tubes in the electronics market, price less than $ 2. Specific to the situation may be different on a different book, the best time to install the digital multimeter on hand Cece. Tube is connected in the forward power output, and then followed by a buy their own power plug inserted in the notebook. Diode is reversed does not matter, the book does not work it wants, and then in turn connected to it.
In this way, the power output voltage drop 0.5V or so, if the drop too much, the book will switch to battery, if the drop too low, the book will charge the battery, the specific number of how you tried on in his book to know.
Of course, if your battery is already full, this circuit is not necessary, you can not have it, directly to the power outlet connected to the books on it.
Point, mentioned at the beginning of the two issues are resolved. It is up to you test results, with an estimated book on the different results may be different, it is best to first try to take a circuit, so it took 10 innocent money :-)
Finally, I wish you good luck! Good use of your battery it!
In the modified plug when the mistake is most likely to engage in anti-polar (diodes engage in anti-polarity does not matter), so you must double-check with a multimeter to measure, with different colors of wire to connect the positive and negative. I do not know engage in anti-polarity power supply will not burn the books, did not try!