Correct use of lithium batteries

Although lithium batteries are widely used in cars, electric cars, mobile phones, tablets, laptops, and other devices, there may be more devices to use in the near future, but for now, devices such as mobile phones and tablets, It's still the closest lithium battery to our power supply. Therefore, it is necessary to make special instructions for the use of lithium batteries on mobile phones.

1, charging

In the use of lithium batteries, it should be noted that after the battery is placed for a period of time, it enters a dormant state. At this time, the capacity is lower than normal, and the service time is also shortened. However, lithium batteries are easily activated. As long as the battery is activated after 3-5 normal charge and discharge cycles, the battery can be activated and the normal capacity can be restored. Due to the characteristics of the lithium battery itself, it is determined that it has almost no memory effect. Therefore, the new lithium battery in the user's mobile phone does not require special methods and equipment during the activation process. Not only in theory, but in my own practice, the "natural activation" of charging from the very beginning is best. For the "activation" of lithium batteries, there are many arguments: The charging time must be more than 12 hours, repeated three times to activate the battery. This saying that "the first three charges should be charged for more than 12 hours" is obviously a continuation of nickel batteries (such as nickel cadmium and nickel hydrogen). So this statement can be said to be misrepresented at the beginning. The charge-discharge characteristics of lithium batteries and nickel batteries are very different, and it can be very clear to everyone. All the serious formal technical information I have consulted emphasizes that overcharge and overdischarge can cause great damage to lithium batteries, especially liquid lithium-ion batteries. Therefore, charging is best done in accordance with standard time and standard methods, especially without overcharging for more than 12 hours. In general, the charging method described in the mobile phone manual is a standard charging method suitable for the mobile phone.

In addition, lithium cell phones or chargers will automatically stop charging after the battery is full, and there is no so-called "trickle-down" charging of nickel-electric chargers that lasts for more than 10 hours. In other words, if your lithium-ion battery is filled, it is also a waste charge on the charger. Neither of us can guarantee that the characteristics of the battery's charging and discharging protection circuit will never change and the quality will be foolproof, so your battery will be on the edge of danger for a long time. This is another reason why we oppose long charging. In addition, after charging for some mobile phones for a certain period of time, if the charger is not removed, the system will not only stop charging, but will also start the discharges and charges cycle. This may have its own purpose, but it is obviously not good for the life of batteries and cellphones / chargers. At the same time, long charging takes a long time and often needs to be carried out at night. According to the situation of China's power grid, the voltage at night is relatively high and fluctuating in many places. As has been said before, lithium batteries are very delicate, and they are much less resistant to fluctuations in charge and discharge than nickel, and this poses additional risks. In addition, another aspect that can not be ignored is that lithium batteries are also not suitable for over-discharge, and over-discharge is also very unfavorable to lithium batteries. This leads to the following questions.

2, when should the charging start in normal use

In the forum, this statement can often be seen, because the number of charge and discharge is limited, so the power of the cell phone battery should be recharged as much as possible. However, an experimental table on the charge and discharge cycle of lithium ion batteries was found. The data on the cycle life are listed below:

Cycle life (10 % DOD): & GT; 1,000 times.

Cycle life (100 % DOD): & GT; 200 times

The DOD is an English abbreviation for discharge depth. From the table, it can be seen that the number of rechargeable times is related to the discharge depth, and the cycle life of 10 % of the DOD is much longer than that of 100 % of the DOD. Of course, if the relative total capacity of the actual charge is: 10 % * 1000 = 100, 100 % * 200 = 200, the latter's full charge discharge is still better. Under normal circumstances, you should charge the battery on a reserved basis according to the principle of recharging the rest of the battery, but if the battery is expected to be unable to maintain the entire day on the second day, it should start charging in time. Of course, if you want to carry a charger to the office is another matter. And when you need to recharge to cope with an important event that is expected to lead to busy communication, even when the battery has a lot of power, then you just charge in advance because you don't really lose "1" charge cycle life. That is, "0.x" times, and often this X will be small. The principle of recharging the battery after it's used up is not to go to extremes. A saying that is as widespread as long charging is that "try to use up the battery of the mobile phone, and it is best to use automatic shutdown." This practice is actually just a nickel battery practice. The purpose is to avoid the memory effect. Unfortunately, it is also circulating on lithium batteries. Some people have used the example of automatic shutdown because they still do not charge after the warning that the battery is too low. As a result, the mobile phone in this example did not respond to the later charging and booting, and had to send customer service maintenance. This is actually because the battery is too low due to excessive discharge, so that it does not have normal charging and boot conditions.

3, for the correct use of lithium battery cell phone important tips

To sum up, my most important reminder of the charge and discharge problem of lithium battery phones in use is:

1, according to the standard time and program charging, even if it is the first three times to do so;

2, when the mobile phone electricity is too low prompt, should start charging as soon as possible;

3. The activation of the lithium battery does not require a special method. The lithium battery will naturally activate during normal use of the mobile phone. If you insist on using the "first three 12-hour long charge activation" method that is circulated, it will not actually work. Therefore, all the pursuit of 12 hours of ultra-long charging and the use of lithium battery mobile phones to automatically shut down are wrong. If you have done it in the wrong way, please correct it in time, maybe it is not too late. Of course, in the case of good quality of the mobile phone and charger protection and control circuit, the protection of the lithium battery is quite guaranteed. So the understanding of the charging rules is the key point, and in some cases it is also possible to make some concessions. For example, if you find that your phone must be charged before you go to sleep at night, you can also start charging before going to bed. The point is that you should know what the right approach is and don't deliberately follow the wrong way.

2.Battery maintenance

In fact, the battery does not have much to take into account. In other words, it is not very useful to take into account. How many times a battery can be used, the difference is more from the individual difference in the battery itself, rather than the method of use. In addition to its own battery quality, the battery's own service life is limited. Once the battery is off the production line, its life begins to pass. Lithium batteries have a life span of two to three years, whether you use them or not. One of the important reasons for the decrease in battery capacity is the increase in internal resistance due to oxidation. Finally, the resistance of the cell will reach a certain point. Although the battery is full at this time, the battery can not release the stored electricity. Many friends believe that the initial use of lithium batteries should be charged for more than 16 hours, so that the battery can be fully activated. In fact, there is no basis for doing so. This is only a popular method of charging nickel-metal hydride or nickel-cadmium batteries in the past. It does not apply to lithium ion batteries. Because this lithium-polymer-centered battery has no memory effect in theory, even if it does, it is completely negligible. Therefore, it only takes about 3 hours to flush it. If the display charging is completed and there is no need for external power supply for the time being, then the power can be pulled off without waiting for such a long time.

Myth number one: PSP needs to be repeatedly charged and discharged three times to activate the battery. Unless the PSP purchased is a product that has been in stock for more than one year, this does not need to be done because the current battery core has been activated at the time of manufacture, and the core has undergone an equivalent activation test when packaged into a PSP battery., So you get the battery, has been activated, three more charge-discharge process is just unnecessary to increase the loss of the battery.

Myth 2: The first charge must be enough for 12 hours. This is suitable for those nickel-metal hydride battery devices that did not have battery control circuits, but it is a joke for PSP that now has an intelligent charge and discharge control module. When the PSP battery is full, the charging current will be automatically cut off. And displayed in the system as "external power supply." Even if you continue to charge for 120 hours, there will be no change in status. Generally, 3 hours are completely full. The remaining "charging" is only a waste of time. Instead, when you get a new machine, you should discharge the electricity first and then charge it again.

Myth 3: Battery needs to be fully charged once a month. For nickel-metal hydride batteries with strong memory effects, this is a must, but for lithium batteries, this cycle is too frequent. Lithium batteries theoretically eliminate memory effects, and even if they do, they have greatly reduced the degree to which they are negligible. If you use the battery frequently, you should discharge the battery to a relatively low (about 10 to 15 %) recharge, but if the discharge is so that the machine can not turn on(0 to 1 %), It is a deep discharge that has greater damage to the lithium battery. Generally speaking, such an operation can be done once every 2 months. If you rarely use batteries, just do it every three months.

Myth 4: Work while charging, or continue to use external power after charging can damage the host and battery. This is the most ridiculous argument. How many reactions can be obtained in practice from the theoretical arguments of the so-called holes, electrons, and secondary charges? The views of the battery industry academia are not uniform in the first place. Theory is still divided, how to guide consumers to use the actual? The losses of the battery are divided into normal losses and harmful losses. The actual losses caused by the use of external power supplies and the use of side charges are completely within the normal loss range of the battery, that is, no matter how systematic theoretical maintenance measures are taken. Batteries age, and it's like how magical cosmetics and maintenance don't stop a beautiful woman from becoming an old woman. At best, it's just a delay. This is by no means explained by theory -- respect for practical experience is the correct and scientific concept of understanding. Some people may say that the only way to avoid battery aging is not to use it(so many people will choose to take the battery down), but this makes the PSP portability meaningless. Second, even if the battery is in storage, it is also naturally aging with the extension of time. Battery is actually a semi-consumable product, so long as the battery brings you enough convenience and happiness, I think their sacrifice is valuable.

The page contains the contents of the machine translation.