A basic overview of lithium-ion batteries for mobile phones

Now mobile phone basically batteries are all lithium ion batteries, so the following is about knowledge in view of the lithium ion battery charging. Ni-Mh batteries is different, don't talk about here.

1, the nominal voltage of 3.7 V lithium ion batteries (3.6 V), charge cut-off voltage of 4.2 V, 4.1 V, according to the label of batteries have different design).Lithium ion batteries (specification is: lithium ion secondary battery)

2, requirements for lithium ion batteries (GB/T182872000 specification) : first of all, constant current charging, namely must be current, and battery voltage with the charging process gradually increases, when the battery voltage of 4.2 V, 4.1 V), constant voltage charging, instead of constant current charging for the voltage must be current depending on the degree of saturation batteries, as the charging process continue to gradually reduce, when reduced to 0.01 C, think charging termination.(C is a sign of nominal capacity battery control current methods, such as the battery capacity is 1000 mAh, 1 C is the charging current 1000 mA, attention is mA not mAh, 10 mA is 0.01 C.)Normative representation is 0.01 C5A, of course, I'm here to simplify.

3, why do you consider 0.01 C for the charging end: this is stipulated in the national standard GB/T18287-2000, are also discussed. Used widely to 20 ma to end, posts and telecommunications industry standard YD/T998-1999 in the same way, that no matter how much battery capacity, to stop the current 20 ma. National standard of 0.01 C help charging more full, through identification on the part of the manufacturer. In addition, national standard rules on the charging time not more than eight hours, that is to say even if haven't reached 0.01 C, 8 hours, also think charging end.(quality no problem of the battery, should be within 8 hours at 0.01 C, battery quality is bad, also meaningless wait)

4, what the difference between the battery is 4.1 V or 4.2 V: consumers are unable to distinguish, it depends on batteries manufacturer's product specifications. Some brand of batteries is 4.1 V and 4.2 V is universal, such as A&TB (Toshiba), domestic manufacturer base is 4.2 V, but there are exceptions, such as Tianjin lishen is 4.1 V (but now also is according to 4.2 V).

5, batteries charging of 4.1 V to 4.2 V would be like: can make the battery capacity increase, the feeling is very good, the standby time increases, but will shorten the service life of the battery. The original 500 times, for example, reduced to 300 times. Similarly, the 4.2 V batteries overcharge, will shorten life. Lithium ion battery is very delicate.

6, since the battery with protection plate, whether we can rest assured: no, because of the protective plate as parameter is 4.35 V (this is good, and poor in 4.4 to 4.5 V), protective plate is one thousand, if every time the overcharge, the battery will soon decay.

7, how much of a charging current is appropriate: theoretically, the smaller the battery is good. But you can't for a piece of battery such as 3 days. National standard of low charge ratio is 0.2 C (charging arbitration system), still above the 1000 mAh capacity of the battery, for example, is 200 ma, so we can estimate the battery only can charge more than five hours. Capacity (mAh = current mA * h)

National technical supervision departments lithium electricity charging capacity, is a high rate of 1 C, low discharge of 0.2 C, with time to calculate the capacity value, test times, 5 times capacity to one end of the test.(that is, there are 5 times, if the first test is qualified, the back of the four do not) allowed once precycling before detection, with 1 C is constant current charging 4.2 V namely stop, without following the process of constant pressure to 0.01 C, no 14 hours more.

8, lithium ion battery can bear how much charging current: when the factory test can be very high, but the elevation specified as 1 c ratio, also more than the battery, for instance, can be more than an hour. Such a large charging current, battery can bear? For the current lithium ion batteries, it is something. There is no national standard for the charger, which is performed by ministry of posts and telecommunications industry standard YD/T9981999/2, which sets the current of the charger shall not be greater than 1 c.

9, what is the life: simple refers to the battery after N times, after 1 c, 1 c discharge capacity decreased to 70%, when N is life. It is not to say that you can also use 300 times, 301 times cannot be used. National standard specified life should not be less than 300 times. We usually use the condition of no detection so harsh, longer service life.

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