Four stages of charging a lithium battery

With the continuous development of new energy technology, lithium ion battery currently widely used in all kinds of products, including buses, new energy vehicles, electric bicycles, home laptop, mobile phones, digital camera, tablet, etc., which are inseparable from the lithium ion battery. Due to its circulating superior performance, it can fast charge and discharge. Charging efficiency is as high as 100%, has large output power and long service life, and does not contain toxic and harmful substances, which is known as green battery. However, lithium ion battery is an important problem in the process of using security. Once it has improper usage, it may affect battery performance and life, and even can cause cell combustion and explosion. Therefore, in the process of battery production, protective measures are necessary.

Lithium ion battery is to prevent from lithium battery protection board in the process of using some irregularities and destroy cell normal function of a product, its essence is a PCB with protection chip, board generally has a + B, B1, B2...Bn, B -, P +, P -, CH - such as basic power input and output end and TH, ID and other information read end, B +, B1, B2,...Bn, B -, and the output end of the batteries directly connected, P +, P -, CH - and connected to the load. In the actual production of lithium battery in the process, in order to ensure that finished products the lithium battery product quality, testing department must be the protection of new board function test.

Lithium electricity the four stages of shallowly discussed pool charging process

The correct way of charging the battery

The use of lithium ion battery we will talk at three points:

1, how to new battery

That should be paid attention to in using lithium battery, battery placed after a period of time to enter a dormant state, capacity is lower than normal at this time, use time is shortened. But the lithium battery is easy to activate, if after 3-5 times the normal charge and discharge cycle can activate cells, back to normal capacity. Due to the characteristics of lithium battery itself, determines its almost no memory effect. New lithium-ion batteries in the user's phone in the process of activation, is don't need special method and the device. Is so in theory, not only from my own practice, from the start with a standard method to charge this way of "natural activation" is the best. For the "activation" of lithium-ion batteries, many say: charging time must be more than 12 hours, if you do this three times, in order to activate the battery.

This "the first three time charge to charge more than 12 hours", apparently from nickel battery, such as nickel cadmium and nickel metal hydride) continue down. So that, the outset misinformation, so to speak. Lithium-ion and nickel batteries charging and discharging characteristics have very big difference, and can be very clear tell you, I have looked at all serious formal technical data will emphasize overcharge and over discharge of lithium batteries, especially liquid lithium ion battery caused great damage. And charging in accordance with the best charging standard time and standard methods, especially don't charging for more than 12 hours long. Usually, the introduction of charging method, on the phone's manual standard charging method is suitable for the mobile phone.

In addition, the lithium battery cell phone or the charger will automatically stop after the battery, and there is no nickel electric charger of the so-called "trickle charging for 10 hours. That is to say, if your lithium battery, after full on the charger is Bai Chong. And none of us there is no guarantee that the battery charge and discharge protection circuit will never change and quality according to the features of foolproof, so your battery will be on the brink of danger for a long time. This is another reason we object to a longer charge. Charging in addition on the phone for some, after more than a certain amount of time, if you don't go to remove the charger, the system does not stop charging, will also begin to discharge - charging cycles. Perhaps this vendor has its purpose, but apparently for life of battery and mobile phone/charger is unfavorable.

At the same time, the charging takes a long time long, often need to be done in the night, and to power grid in China, many places are relatively high voltage in the night, and volatile. Have already said, in front of the lithium battery is very delicate, it is better than nickel electric resistance to fluctuation in charging and discharging ability worse, so it brings the risk of additional. In addition, another aspect cannot be ignored is the lithium battery is also not suitable for discharge, over discharge to the lithium battery is bad also. This leads to the following questions.

Discuss the four stages of the to lithium batteries

2, when in normal use should start charging

On our BBS, often can see this statement, because the number of charge and discharge is limited, so should be mobile phone battery electric light recharging as much as possible. But I find a lithium ion battery charge and discharge cycle experiment table, the cycle life of the data are listed as follows:

Cycle lifetime (10% DOD) : "1000 times

Cycle lifetime (100% DOD) : "200 times

The DOD is the abbreviation of the depth of discharge. From the table, but the depth of the number of charging and discharging, 10% DOD cycle life than 100% DOD much longer., of course, if the conversion to the actual charge relative to the total capacity: * 1000 * 200 = 200 = 100100%, 10% of the latter to fully charge and discharge is still relatively good, but in front of the net friend of the idea to do some correction: under normal circumstances, you should have a reservation, according to the principle of battery remaining power run out to refill charging, but if your batteries in your expected to 2 days can't insist on the whole during the day, it should start charging in a timely manner, of course, if you are willing to carry the charger to the office when BieLun again.

And you need to charge for the upcoming is expected to lead to the communication of the most important events in the busy, even when there are a lot more than battery, so you can just charge in advance, because you didn't really lose "1" time charge cycle life, namely "0. X", and often the x will be small. The principle of battery remaining power run out to refill is not want you to extremes. As widespread and long charging a saying that is "as far as possible put the cell phone battery power run out, had better use automatic shutdown".

The practice of this kind of practice is just nickel batteries, which purpose is to avoid the memory effect, unfortunately it also in lithium battery of circulating on today. Once someone because the cell phone battery low warning, without a charge to continue using has been used examples of automatic shutdown. The result from this example phone no response in the later charging and boot, had to send to the maintenance of the service. This is because the battery voltage is too low, caused by the excessive discharge that do not have normal charging and boot conditions.

Discuss the four stages of the lithium batteries

3, the correct approach for lithium battery cell phone

Boil down to, I on the problem of lithium battery cell phones in use is the most important tip:

1, according to the standard time and procedure charging, even so will three times before;

2, when there is a hint when battery power is too low, should try to start charging in a timely manner;

3, the activation of the lithium battery does not need special method, in the normal use of mobile phone lithium batteries will naturally activation. If you are determined to use of "three times before 12 hours long charging activation" approach, in fact there will be no effect. Therefore, all the pursuit of 12 hours long use the lithium battery cell phone charging and automatic shutdown, are wrong. If you've made according to the error, please correct in time, maybe it is not too late. Of course, in the mobile phone and charger itself under the condition of good quality, protection and control circuit for lithium battery protection still has quite a guarantee. So the understanding of charging rules is the key, in some cases, also can make some concessions.

Such as you find mobile phone must be charge before you sleep at night, you can also start charging before going to bed. The crux of the problem is that you should know what is the right thing to do, and do not deliberately accord to error.

Discuss the four stages of the to lithium batteries

The four stages of lithium battery charging process

Charging or discharging rate usually expressed according to battery capacity. The speed is called C rate. C rate is equal to the specific conditions of charging or discharging current, are defined as follows:

I=M&TImes; Cn

Among them:

I = charge or discharge current, A

M = C multiples or scores

C = rated capacity values, Ah

N = number of hours (corresponding to C).

With double C discharge rate of battery will be released within an hour of nominal rated capacity. For example, if the nominal capacity is removable and rechargeable 1000 mAhr, 1 C discharge rate corresponding to the discharge current 1000 ma, the rate of C / 10 corresponding discharge current of 100 ma.

Manufacturers calibration of the battery capacity usually refers to the n = 5, the 5 hours of discharge capacity. For example, the battery at 200 ma electric constant exile can provide 5 hours of work. In theory the battery at 1000 ma electric constant exile can provide 1 hour of work time. However, in fact, due to the large battery discharge performance is reduced, and the working hours will be less than 1 hour.

So how to correctly for lithium ion batteries? Lithium ion battery is most suitable for the charging process can be divided into four stages: a trickle charging, constant current, constant voltage charging and charging termination.

Phase 1: a trickle charge -- a trickle charge used to completely discharge the battery unit first pre-charge charging (recovery).When battery voltage is lower than 3 v or so, first USES the maximum 0.1 C constant current for rechargeable batteries.

Phase 2: constant current charging, when the battery voltage rises to a trickle charge above the threshold value, improve the battery by constant current charging current. Constant current charging current between 0.2 C and 1.0 C. Constant current charging current does not require a very precise, accurate constant current. In the design of linear charger, with the rise of the battery voltage current rise as far as possible to reduce the transmission transistor on the heat dissipation problem.

Greater than 1 c constant current charging will not shorten the cycle time, so this kind of practice is not desirable. When charging at higher current, due to the electrode reaction of overvoltage and battery internal impedance voltage rise, the battery voltage will rise more quickly. Constant current charging stage will be shorter, but due to the following stage of constant voltage charging time will increase, so the total charge will not shorten the cycle time.

Phase 3: constant voltage charging, when the battery voltage up to 4.2 V, the end of the constant current charging, began to constant voltage charging stage. In order to make the best performance, voltage tolerance should be better than + 1%.

Stage 4: charging termination - unlike nickel battery, do not recommend continuous trickle charging of lithium ion batteries. Continuous trickle charge will cause metal lithium plate electroplating effect. This will make the battery is not stable, and could lead to a sudden automatic quick collapse.

Discuss the four stages of the to lithium batteries

There are two kinds of typical charging termination methods: USES the minimum charging current judgment (or a combination of both) or use a timer. The minimum current method to monitor stage, the charging current constant voltage charging, and reduce the charging current to the termination of charging 0.02 C to 0.07 C range. The second method from constant voltage charging stage at the beginning of time, continue to charge two hours after the termination of charging process.

Completing completely discharge the battery by those four stages of charging methods takes about 2.5 to 3 hours. Senior charger is adopted more security measures. For example, if the battery temperature exceeds the specified window (usually 0 ℃ to 45 ℃), and then the charging will be suspended.

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