What is a Lithium Cell Phone Battery?

The lithium battery of the mobile phone is mainly composed of a plastic case upper and lower cover, a lithium battery, a protection circuit board (PCB), and a recoverable fuse (polyswitch). Some manufacturers also have components such as NTC, identification resistance, vibration motor or charging circuit. Lithium batteries are durable products, so they are not delicate. You can treat them calmly, and you do not need to equip them with expensive original chargers. Generally there are brands of ordinary chargers, the price is 15-20 yuan, eliminating the need to rely on mobile phones for direct charging.

Cell phone lithium battery

(1) Lithium battery: provide rechargeable

There is a fast charge (about 2-3 hours) and a slow charge (up and down of 10 hours). If the battery is more, fast charge is better.

In addition, due to the characteristics of lithium batteries, discharge and overcharge operations are not required. The battery life depends entirely on the effective charging time. In other words, even if you start charging only half of the time, it has no effect on battery life.

1. Recognize memory effects

Battery memory effect refers to the reversible failure of a battery, that is, the performance that can be restored after a battery failure. The memory effect means that the battery automatically maintains this specific tendency after it has been subjected to a specific working cycle for a long time. This earliest definition was in nickel-cadmium batteries. Nickel-cadmium pouch batteries do not have a memory effect, and sintered batteries have a memory effect. Today's nickel metal-hydrogen (commonly known as nickel-hydrogen) batteries are not restricted by this definition of memory effect.

Because of the improvement of modern nickel-cadmium battery technology, the aforementioned memory effect has been greatly reduced, and another phenomenon has replaced this definition, which is the "lattice" of nickel-based batteries. Generally, nickel-cadmium batteries are affected by these two The combined effect of the effects, while the nickel-metal hydride battery is only affected by the "lattice" memory effect, and the impact is smaller than the nickel-cadmium battery.

In practical applications, the method of eliminating memory effects has strict specifications and an operating procedure. Improper operation will be counterproductive.

For nickel-cadmium batteries, the normal maintenance is regular deep discharge: On average, a deep discharge is performed once every month (or 30 cycles) (discharge to 1.0V / cell, foreigners call it exercise), and it is usually used as much as possible. Or the use of shutdown and other means can alleviate the formation of memory effects, but this is not exercise, because instruments (such as mobile phones) will not use 1.0V / cell to shut down, you must use special equipment or wiring to complete this work Fortunately, many NiMH battery chargers have this feature.

For nickel-cadmium batteries that have not been subjected to exercise for a long time, due to the accumulation of memory effects, capacity recovery cannot be performed with exercise. At this time, deeper discharge is required (foreigner called recondition). This is a kind of battery that uses a small current for a long time. A process of discharging to 0.4V per section requires professional equipment.

For nickel-metal hydride batteries, exercise is performed approximately once every three months to effectively alleviate the memory effect. Because the cycle life of nickel-metal hydride batteries is far lower than that of nickel-cadmium batteries, this method is rarely used.

Recommendation 1: It is not necessary to discharge the battery before each charge, and it is harmful because the battery life is shortened unnecessarily.

Recommendation 2: It is not advisable to use a resistor to connect the positive and negative electrodes of the battery to discharge. The current cannot be controlled, and it is easy to over-discharge to 0V, and even cause the polarity of the battery of the series battery pack to be reversed.

2.Does the battery need to be activated?

The answer is that the battery needs to be activated, but this is not what the user has to do. The author has visited the lithium-ion battery production plant. Before leaving the factory, the lithium-ion battery must go through the following process: the lithium-ion battery case is filled with electrolyte-sealing-forming, that is, constant-voltage charging, and then discharging, so that several cycles, so that The electrode is fully wetted with electrolyte and fully activated until the capacity reaches the required level. This is the activation process-capacity division, which is to test the capacity of the battery. Select batteries of different performance (capacity) to classify, classify the battery, and perform capacity matching. The lithium-ion battery that comes out in this way is already activated in the user's hands.

The nickel-cadmium batteries and nickel-metal hydride batteries commonly used by all of us are also manufactured after activation. The activation process of some of these batteries requires the battery to be open and sealed after activation. This process may only be completed by the cell manufacturer.

There is a problem here: the battery delivered by the battery factory is in the hands of the user. This time can be very long, as short as 1 month and as long as half a year. At this time, because the battery electrode material will be passivated, the manufacturer recommends the first use. The battery is best to be fully charged and discharged 3 to 5 times in order to eliminate the passivation of the electrode material and achieve the maximum capacity.

In the three national standards for nickel-metal hydride, nickel-cadmium, and lithium-ion batteries issued in 2001, the initial capacity testing has clearly stipulated that the battery can be deep-charged and deep-charged 5 times. To stop. This is a good explanation of what I said.

Then it is also possible to call it "second activation". The "new" battery used by the user for the first time should be subjected to deep charge and discharge cycles as many times as possible.

However, according to the author's tests (for lithium-ion batteries), lithium-ion batteries with a storage period of 1 to 3 months are subjected to deep charge and deep discharge cycling, and the capacity increase phenomenon is almost non-existent.

The following principles should be followed when using lithium batteries for mobile phones:

1. It should not be completely discharged, and the lithium battery is often charged. The damage to the lithium battery by repeated and random charging is very small and can be ignored.

2. Store the lithium battery that needs to be stored in a cool place. Remember not to put it in the refrigerator. Avoid placing it in a hot car, such as storing it for a long time, charge the battery to 40% and place it.

3. If you are using a fixed power source most of the time, please remove the battery and store it in a cool place.

4. It is not necessary to purchase a spare lithium battery for storage, so this battery is actually wasted.

Batteries are used. As long as you pay attention to reasonable use and storage methods, there is no need to take excessive care of them, and it is most important to make them "contribute" to us as much as possible.