What is a Rechargeable Battery?

Rechargeable battery is a rechargeable battery with a limited number of recharges. It can be used with a charger. The market usually sells No. 5 and No. 7, but there are also No. 1. The advantages of rechargeable batteries are economical, environmental protection, sufficient power, suitable for high-power, long-term electrical appliances (such as walkmans, electric toys, etc.). The voltage of the rechargeable battery is lower than that of the same type of disposable battery. The AA battery (charge 5) is 1.2 volts, and the 9V rechargeable battery is actually 8.4 volts. Now generally the number of charging can be around 1000 times. As of February 2012, there are only five types: nickel-cadmium, nickel-hydrogen, lithium-ion, lead storage, and iron-lithium.

The active material on the positive plate of a lead-acid battery is lead dioxide, the active material on the negative plate is sponge-like pure lead, the electrolyte is a sulfuric acid solution of a certain concentration, and the electromotive force between the plates is about 2V.

The active material on the positive plate of the nickel-cadmium battery is nickel oxide powder, and the active material on the negative plate is cadmium oxide powder. The active materials are respectively wrapped in perforated steel strips, which become the positive and negative plates of the battery after pressure forming. The electrolyte is usually a potassium hydroxide solution. The open circuit voltage of the battery is 1.2V.

The material of the positive plate of the nickel metal hydrogen battery is nickel oxide powder, the material of the negative plate is a hydrogen absorbing alloy, and an electrolytic potassium hydroxide solution. The open-circuit voltage of the battery is 1.2V. LiCoO2 composite metal oxides are used for lithium ion batteries to form anodes on aluminum plates, and lithium carbon compounds are used to form cathodes on copper plates, with submicron-sized microporous polyolefin film separators between the plates, electrolytic The liquid is an organic solvent. The open circuit voltage is 3.6V.

Lithium polymer battery is an improved type of lithium-ion battery. There is no battery fluid. Use polymer electrolyte instead, which is more stable than ion battery. Open circuit voltage is 3.6V.

The battery capacity represents how much power the battery can store. The numbers we see on the battery packaging generally refer to the battery capacity identification. Expressed in unit ampere hours or milliamp hours. It is a composite unit composed of the product of the current unit and the time unit, which represents the ability of the battery to continuously discharge at a constant current. A fully charged battery can be discharged with 200mA current for 10 hours. Multiplying the current and time we can get the capacity of this battery is 2000mA.H. If it is discharged with 400mA, the available time is 5 hours.

Energy density: The electrical energy capacity contained in a unit volume or unit weight. For the same amount of electricity, a battery with a high energy density can be smaller in size and lighter in weight.

C current: refers to the amount of current that the fully discharged battery is discharged or the exhausted battery is fully charged within one hour. In fact, it is the numerical value of the ampere-hour capacity. For a battery with a capacity of 1800mA, the C current is 1800mA. 2000mA. Capacity battery, C current is 2000mA.

Open circuit voltage: refers to the potential difference between the two poles of the battery.

Memory effect: The new battery has the smallest electrode material and the largest electrode surface area. The content of the battery is crystallized due to use. After the crystallization is formed, the grains increase, also known as (passivation), which reduces the available electrode area, and the grown grains will increase the self-discharge and make the battery Reduced capacity and impaired performance. This is the memory effect. The memory effect occurs because of repeated partial charging and discharging of the battery.

Self-discharge rate: After being charged, the battery will gradually lose its power even when not in use. Generally, the higher the temperature, the more significant the self-discharge.

Nickel-cadmium: Yes

Disposable batteries are commonly referred to as "depleted" batteries, because when they run out,

Rechargeable Battery

The charging of rechargeable batteries has always been the focus of people's attention. Correct and good charging methods can ensure the battery life. There are a variety of recommended charging methods for rechargeable batteries. Different charging methods have different requirements for the charger's circuit, which naturally affects costs.

The memory effect is a major enemy of rechargeable batteries, and is generally considered to be a long-term incorrect charging.

1. The charger is smoking: Unplug the charger quickly and remove the battery. Charger smoke is generally caused by the transformer being burnt out due to excessive mains voltage;

2. The battery is hot (the outer packaging will crack in severe cases): quickly remove the battery and cover it with a hard box for 1 hour to prevent possible danger. Hot battery is usually caused by short circuit or abnormal internal battery. At this time, you should check the charger circuit is normal, and check whether the battery voltage is abnormal (heating of the rechargeable battery when charging is normal);

3

1. Read the battery manual carefully, use the recommended battery, and follow the operating procedures;

2. Check whether the electrical and battery contacts are clean, wipe them with a damp cloth if necessary, and install them in the correct polarity after drying;

3 Do not allow children to replace batteries without adult supervision. Keep small batteries such as AAA out of the reach of children.

4 Do not mix new and old batteries or different types of batteries, especially dry batteries and rechargeable batteries.

5. Do not attempt to regenerate the primary battery by heating, charging or other methods to avoid danger;

6. Do not short-circuit the rechargeable battery, otherwise it will damage the battery and cause heat to burn the battery.

7. Do not heat the battery or throw it into water or fire. Putting the battery in water will invalidate the battery. Putting the battery in fire will cause the battery to rupture, or

The fierce chemical reaction explodes and hurts people, or produces some harmful gases and soot.

8. Do not disassemble the battery, or try to penetrate the battery with a sharp object, as the electrolyte inside the battery will hurt the skin and clothing.

9. After using the electrical appliances, the power switch should be turned off to avoid fire due to heat, etc .;

10 The battery should be removed from the electrical appliances that have not been used for a long time, and the battery should be stored after being vented. And take out charge and discharge once every 3 months;

11. The battery should be stored in a cool, dry place and avoid direct sunlight;

12. Nickel charger and lithium charger cannot be mixed;

13. The battery cannot be used for welding. The high temperature generated during welding will damage the internal structure of the battery, which may render the battery unusable and even dangerous;

14. Can not be reversely charged. Reverse charging is equivalent to overdischarge. Overdischarge will cause adverse reactions inside the battery and cause serious damage to the battery.

The amount of gas is likely to cause chemical leakage in the rechargeable battery.

15. Do not place rechargeable batteries in rain. Rain water can conduct electricity. When the battery is placed in rain water, a short circuit is likely to occur, causing the battery to discharge due to instantaneous high current.

Hotness can damage the battery or cause danger.

16. If the battery cannot be stored in a high temperature or high humidity environment, the reaction of the battery itself will be intensified, so it cannot provide sufficient capacity to the consumer. In addition,

Under high temperature and humidity, the aging speed of the battery will be greatly accelerated, and it will also corrode electronic components (except for high temperature batteries).

17. Do not insert the positive and negative terminals of the battery upside down, otherwise it will cause the battery to bulge or rupture;

18. When storing the battery, it is best not to mix it with metal objects, and do not tear off the insulation film wrapped around it. ^[1]

The most versatile are the No. 5 (AA) and No. 7 (AAA) rechargeable batteries. Many digital cameras, Diskman, Walkman, MD, PDA, etc. need to be used. There are two main types of this type of battery: nickel-cadmium / nickel-metal hydride. The following mainly discusses the problem of nickel-cadmium / nickel-metal hydride. Nickel-cadmium / nickel-metal hydride batteries have AA and AAA models that can directly replace ordinary 5 and 7 disposable batteries. Although the standard voltage of ordinary batteries is 1.5V and nickel-cadmium / nickel-metal hydride batteries are only 1.2V, they generally do not affect the use. .

First introduce an important parameter of the rechargeable battery-the battery capacity, expressed in units of AH (Ah). We can see that it is a composite unit composed of the product of the current unit and the time unit, which represents the product of the continuous discharge time of the battery at a constant current. In small batteries we usually use smaller units of mAH (milliamp hours). For example, an ideal fully-charged battery can discharge for 60 hours with 60MA current. Multiplying the discharge current by time, we know that the capacity of this battery is 600mAH. In theory, if it is used for 600MA discharge, one Hours (divide the battery capacity by the discharge current). The battery capacity parameter represents how much power the battery can store. It is always better in the same volume. Generally, we can see the capacity mark on the battery in retail packaging.

The purchase of such rechargeable batteries is mainly based on capacity and specifications and price. First determine the specifications of the purchased battery. For devices with a relatively small battery compartment or devices that require multiple batteries side by side, pay attention to whether it is appropriate to choose a high-capacity, thick-diameter battery. Rechargeable battery

China s battery exports have grown significantly, but at the same time, EU green barriers, the cancellation of China s battery export tax rebate system, rising raw materials, and the monopoly of high-end markets by foreign companies have restricted the development of China s battery industry. China has become the world's largest battery producing country and the largest battery consuming country, but the products are not updated in a timely manner, and production automation and mechanization are not high. In order to adapt to the development trend of the world battery industry, China must be committed to solar cells and fuel cells

Nickel-cadmium: small capacity with memory effect

Nickel-cadmium according to IEC standard

Let's talk about the discharge process of a battery. A battery is a device that converts chemical energy into electrical energy.

Charging is to reverse the discharge process above

Take lead batteries as an example:

Lead storage batteries were the first practical storage batteries manufactured. The principle is as follows:

The two lead plates A and B were inserted into the sulfuric acid solution. As a result of the action of lead on sulfuric acid, lead sulfate was formed on the two lead plates A and B, and the solution was also saturated with lead sulfate. This is because there is no potential yet. Charge the battery. At this time, the chemical reactions that occur at the poles are as follows:

A; PbSO4 + 2H2O-2e- PbO2 + H2SO4 + 2H +;

B: PbSO4 + 2e- Pb + SO42-;

It can be seen that after charging, PbO2 on A plate becomes positive, and Pb on B plate becomes

European and American countries have started to develop a new type of rechargeable battery called Ni-Zn AA battery (Ni-Zn battery)

Ni-Zn AA battery: The battery size is the same

Integrating rechargeable batteries and charging devices into a new generation of rechargeable batteries

Myth 1: Activation of a new battery

New batteries should be activated by cyclic charging and discharging

usb battery

Battery performance.

Truth: To be precise, the above statement is not a rumor. There is a time lag between the battery from the factory and the user, ranging from one month to half a year. For batteries with a long time difference, the electrode material will be passivated. Therefore, the manufacturer recommends that the battery used for the first time should be subjected to 3 to 5 full charge and discharge processes in order to eliminate the passivation of the electrode material and achieve the maximum capacity. However, manufacturers usually do not pay attention to remind consumers that the full charge and discharge mentioned here should not be deep discharge, but should be controlled at 5% ~ 8%. Otherwise, a new battery is likely to be scrapped.

Biography 2: "First Three" Charging

When a new battery is bought back, it is best to charge and discharge three times. The charging time should be more than 12 hours in order to activate the battery's maximum efficiency.

Truth: In order to reach the perfect saturation state, nickel-metal hydride batteries need to go through the process of "replenishment" and "trickle". This time is generally about 5 hours. At present, the "constant current" and "constant voltage" charging characteristics of lithium-ion batteries control their deep charging time within 4 hours. Once fully charged, the protection circuit inside the battery will automatically stop charging, so this approach is unscientific and practically meaningless.

Someone has experimented with mobile phones. After using the travel charger charger to fully charge the battery, switch to the cradle charger to confirm the battery's saturation level. When he found that the battery charger was still charging the battery, he thought the battery was still not saturated.

. In fact, this test method is not rigorous. The reason is that the indicator light of the charger is not the only standard to detect whether it is truly saturated or not. The reference voltage of the charger is not necessarily equal to the reference voltage of the mobile phone. Maybe I don't think so, and still charging, but whether it is charged, only it knows it.

Myth 3: The Best

As long as the rechargeable battery is used properly, it will reach its optimal state within a certain cycle range and reach its maximum capacity.

For example, early nickel-metal hydride and nickel-cadmium batteries, if used properly and regularly maintained, will reach the maximum value of their capacity in 10 to 200 cycles. Up to 1100mAh).

Truth: This statement is more common in Japanese products, and it can usually be seen in the cycle characteristics chart in its technical specifications. However, for the current mainstream lithium-ion batteries, the peak phenomenon of this cycle does not exist. Because the lithium-ion battery has been discharged from the factory to the end of life, its capacity manifests itself as one cycle at a time, and the capacity has never recovered. Some friends may ask, some ThinkPad notebook users can restore the battery capacity through deep discharge. In fact, it was just an error detection of the test software, and the actual capacity of the battery did not increase at all.

Is the lithium-ion battery in the best state? The answer is yes, it depends on the changes in the ambient temperature. Under normal circumstances, lithium-ion batteries will exhibit excellent performance in an environment of 25 ° C to 40 ° C. When the temperature is low or high, its performance will be greatly reduced. For example, if you use a laptop computer in direct sunlight outdoors, you will not use it for a long time indoors.

Legend 4: The higher the capacity, the better

For two batteries with the same nominal capacity (for example, 800mAh), if one actually measures the capacity as 860mAh and the other as 805mAh, then the 860mAH must be better than the 805mAh.

Truth: Generally speaking, the higher the capacity of the lithium-ion battery of different models (different volumes), the longer it will last. If you ignore the factors such as volume and weight, of course, the higher the capacity, the better. However, it is not necessary for two batteries with the same nominal capacity (such as the above example). Because of the battery with a high actual capacity, it is likely that a substance for increasing the initial capacity is added to the electrode material, and a substance for stabilizing the electrode is reduced. The result is that after cycling for dozens of times, the high-capacity piece quickly decays, while the low-capacity piece remains firm. In order to reduce costs and expand sales, many domestic manufacturers often use this method to produce high-capacity batteries. After half a year of use, users will find that working hours are greatly reduced. In short, the price of increasing capacity is sacrificing cycle life. It is impossible for manufacturers to really increase battery capacity if they are not in the material context of the battery.

Myth 5: Save the battery

If the rechargeable battery is not in use, it should be discharged before being stored.

Truth: In fact, there are more than just the rumors mentioned above. Should lithium-ion batteries be full of storage or lighted up? Preservation will surely confuse many people? The answer to this question starts with its inherent defects, that is, "Aging effect". After being stored for a period of time, even if the lithium-ion battery is not recycled, part of its capacity will be permanently lost. This is because the positive and negative electrode materials of the lithium-ion battery begin their exhaustion process from the factory. The amplitude of aging is also different at different temperatures and saturation levels, and the specific amplitude can be seen in the table.

It can be seen that the higher the storage temperature and the fuller the battery, the larger the capacity. Therefore, for long-term storage of lithium-ion batteries, users should control its power at 40% and store it at 15 ° C or lower. As for nickel-metal hydride and nickel-cadmium batteries, this "aging effect" does not exist. After long-term storage, it only needs to be fully charged and discharged several times to restore its original capacity.

Legend 6: Full charge and subsequent charge

When charging the battery, charge it for another 12 hours after the battery is fully charged. This will help increase battery saturation.

The truth: Under normal circumstances, a qualified charger will automatically turn off the charging circuit after charging is complete, and there is no current, even if the battery is left on the charger for 10 hours. Most mobile phone chargers currently sample this design. Therefore, when the green indicator light is on, just remove the battery and use it. ^[1]