What are you going to do when nickel-cadmium batteries can't charge normally?

Lithium battery is rechargeable battery. Lithium battery charge is commonly has other voltage besides 4.2 V. Lithium battery capacity is xxxmAh, such as 1000 mAh, which means that the power supply current is 1000 ma and can use for 1 hour.500 ma power supply can use for 2 hours and so on.

Lithium battery life and charging ways

Refers to the full number of light.

Fast charging ways: charge, slow filling, trickle charging, constant current charging, etc.

The attention of the lithium battery circuit design problem:

Lithium battery overcharge, over discharge will affect the battery life.

Pay attention to lithium battery charging voltage and charging current. Then select suitable charging chip.

Note to prevent the lithium battery overcharge, discharge, short circuit protection, etc.

The design should pass a lot of testing.

The design of the lithium battery charging circuit

Take chose chip TP4056 here as an example. According to the different can control the charging current biggest. Can design charge indicator, can design that is, how much to charge temperature how many degrees recharged.

Charging protection circuit, the choice chip DW01 and GTT8205 combination, can do short circuit protection, overcharge over discharge protection.

This circuit is mainly composed of lithium battery protection DW01 application-specific integrated circuit, charge and discharge control MOSFET1 (including two n-channel MOSFET) components, such as monomer lithium battery connect between B + and B -, the battery pack from the P + and P - output voltage. When charging, the charger output voltage between P + and P -, current from P + to monomer battery B + and B -, after charging control MOSFET to P - again. In the process of charging, when monomer battery voltage is greater than 4.35 V, application-specific integrated circuit DW01 OC foot switch off output signal charge control MOSFET, lithium batteries immediately stop charging, so as to prevent damage of lithium battery for charging. Discharge process, the monomer battery voltage to 2.30 V, the OD DW01 feet output signal makes discharge control MOSFET shut off, lithium batteries immediately stop discharge, so as to prevent damage of lithium battery due to over discharge, DW01 CS feet for current, output short circuit, charge and discharge control MOSFET turn-on, the pressure drop increase voltage rise rapidly, CS foot DW01 output signal makes charging and discharging control MOSFET switch off quickly, so as to realize over current and short circuit protection.

What is the advantage of lithium battery?

1. High energy density

2. High working voltage

3. No memory effect

4. Long cycle life

5. No pollution

6. Light weight

7. Uniformity

What advantage does lithium polymer battery have?

1. No battery leakage problems, its inside the battery does not contain liquid electrolyte, the use of colloidal solids.

2. Can be made into thin battery: 3.6 V400mAh capacity, its thickness can be thin to 0.5 mm.

3. The battery can be designed into various shapes

4. The battery can be bending deformation: polymer battery maximum bending around 900

5. Can be made into a single high voltage: liquid electrolyte battery only can get high voltage with the number of batteries series, polymer batteries as there is no liquid itself, can be made within the single star multilayer combination to achieve high voltage.

7. Capacity than the same size lithium ion batteries more than double

IEC standards prescribed lithium battery cycle life test as follows:

Battery to 0.2 C to 3.0 V/after

Constant current constant voltage charging 1.1 C to 4.2 V cut-off current 20 ma put on hold for 1 hour to 0.2 to 3.0 V C discharge (a loop)

Repeated cycle after 500 times capacity should be more than 60% of the initial capacity

Standards of the state regulations of lithium-ion batteries charged to maintain test for no relevant standards (IEC).

Battery under the condition of 25 degrees C to 0.2 C to 3.0 / branch, with constant current constant voltage charging 1 C to 4.2 V, cut-off current of 10 ma, under the temperature of 20 + _5 storage after 28 days, to 0.2 to 2.75 V C discharge calculation discharge capacity

What is a secondary battery self-discharge of different types of battery self-discharge rate is how much?

Self-discharge, also known as charged keep ability, it is to point to in the open circuit state, storage battery power to a certain ability to maintain environmental conditions. In general, self-discharge mainly by manufacturing process, material, the influence of storage conditions self-discharge is one of the main parameters of battery performance. In general, the battery storage temperature is lower, and the lower self-discharge, but also should pay attention to the temperature too low or too high could cause cell damage can't use, BYD conventional battery storage temperature range is - 20 ~ 45.A full charge open aside after a period of time, a certain degree of self-discharge belong to normal phenomenon. IEC standard nickel cadmium and nickel metal hydride batteries, under the condition of temperature is 20 degrees of humidity is 65%, and open the way for 28 days, 0.2 C discharge time is more than 3 hours and 3 hours and 15 minutes is up to standard.

Compared with other rechargeable battery systems, liquid electrolyte solar cells significantly low self-discharge rate is about 10% under 25 / month.

What is the battery internal resistance measurement?

Battery internal resistance is refers to the battery at work, current flows through the battery internal resistance, generally divided into ac resistance and dc resistance, due to the rechargeable battery internal resistance is very small, when measuring the dc resistance due to the capacity of electrode polarization, polarization resistance, its real value, so it cannot be measured and the ac impedance measurement can be exempted from the influence of polarization resistance, it is concluded that the real value.

An internal resistance test method is: using the characteristics of the battery is equivalent to an active resistance, battery on a 1000 hz, 50 ma, constant current, the voltage sampling rectifier filter and a series of processing so as to accurately measure.

What is the battery internal pressure of the normal inner pressure is commonly?

Battery internal pressure is due to the charge and discharge process of formed by the gas pressure. The main manufacturing process of battery materials includes the structure factors. Use process generally maintained at the battery internal pressure are normal level, under the condition of overcharge or discharge, the battery internal pressure may be higher:

If the speed is below the speed of the decomposition reaction of compound reaction, the gas to be burned off, and will cause the battery internal pressure rise.

What is the internal pressure test?

Lithium battery internal pressure test: (UL standard)

Simulated battery at an altitude of 15240 m high (11.6 kPa pressure), see if battery leakage or drum.

Specific steps: the battery charging constant current constant voltage charging 1 c to 4.2 V, cut-off current of 10 ma, then put it in a pressure of 11.6 Kpa, temperature of (20 +) _3 storage closet in 6 hours, the battery will not explosion, fire, cracks and leakage.

Ambient temperature has any impact on battery performance?

Of all the environmental factors, the temperature is most affected by the performance of the battery charge and discharge, electrochemical reaction on the electrode/electrolyte interface is associated with the environment temperature, the electrode/electrolyte interface is regarded as the heart of the battery. If the temperature drops, the electrode response rate also fell, assuming that the battery voltage constant, reduce the discharge current, battery power output will decline. If the temperature rise, on the other hand, the battery power output increase, temperature also affects the transfer rate of the electrolyte temperature rise is faster, transfer temperature drop, slow transfer, battery charging and discharging performance would also be affected. But the temperature is too high, more than 45, can destroy the chemical equilibrium inside the battery, cause side effects

What methods of charging control?

In order to prevent the battery overcharge, need to control charging the end, when the battery is full, there will be some special information available to determine whether the charging arrives at the finish line. Generally has the following six kinds of methods to prevent the battery being over-charged:

1. The peak voltage control: by the end of the test judging the peak voltage of charging battery.

2. DT/dT control: by detecting battery charge peak temperature gradient to determine the end point;

A full battery 3. T control: when the difference between the temperature and environmental temperature will reach maximum;

4. - V control: when the battery charge after reaching a peak voltage, voltage drops a certain value

5. Timing control: by setting the charging time to control the charging end, generally set should fill in the time needed for 130% of nominal capacity to control;

6. TCO control: considering safety and characteristics of the battery should avoid high temperature (high temperature battery charge except), therefore should stop charging when the battery temperature 60.

What is the charge, have any impact on battery performance?

Charging is refers to the battery charge through a certain process, continue to charge.

Because, in the design of the cathode capacity higher than the positive capacity, therefore, the positive of gas through the diaphragm paper and negative cadmium composite. So in general, the battery internal pressure does not have obvious rise, but if the charging current is too large, or the charging time is too long, doesn't produce oxygen is consumed, it may cause higher internal pressure, battery deformation, leakage, etc. Bad phenomenon. At the same time, its performance will be significantly reduced.

What is the discharge, have any impact on battery performance?

After internal storage capacity, voltage reaches a certain value, continue to discharge can cause over discharge, generally close according to the discharge current to determine the discharge voltage.0.2 C - 2 - C discharge generally set V / 1.0, 3 C, such as 5 or 10 C discharge set to 0.8 V/C, the battery discharge may have disastrous consequences for the battery, especially large current discharge, or repeatedly put a greater impact on the battery. In general, a discharge will make the battery internal pressure increases, the cathode active material is reversible damage, even if the charge is only partially restored, capacity will have obvious attenuation.

Different capacity of the battery together with will appear what problem?

If the different capacity or used old and new batteries get together, they possibly have leakage, the phenomenon such as zero voltage. This is because in the process of charging, charging capacity differences lead to some battery overcharge, some of the battery is not full of electricity, high capacity of the battery discharge power, not put up the low capacity is put. It has vicious cycle, cell damage and leakage or low voltage (zero).

What is the battery explosion how to prevent the battery? The solid material of any part of the instantaneous discharge is pushed to the distance from the battery more than 25 cm, called the explosion. Discriminant battery explosion or not, the experiment uses the following conditions. Will cover a network experiment batteries, battery in the middle of, any side is 25 cm from the net. Network density of root/cm, 6 and 7 cables with soft aluminium wire diameter is 0.25 mm, without solid part through the net, if the experiment proved that the battery was not an explosion.

Lithium batteries in series

Due to the battery in the process of production, from film to become a finished product should pass a lot of working procedure. Even after the strict test procedure, make each group of the power supply voltage, resistance, capacity is consistent, but the use of a period of time, also can produce the difference of this or that. As a mother gave birth to twins, newborn may be identical, as a mother is difficult to distinguish. However, when two children grow, can produce differences in one way or another lithium power battery same way. Use after period of time have differences, adopt the way of the voltage control is difficult to apply to lithium power battery, such as a 36 v battery pile, must use 10 only batteries in series. Overall charge control voltage is 42 v, and discharge the control voltage is 26 v. With overall voltage control method, the initial use phase due to battery consistency especially good, perhaps there will not be any problem. In use for a period of time after the battery internal resistance and voltage fluctuations, forming an inconsistent state, (inconsistent is absolute, consistency is relative) this time still use whole voltage control can't achieve the goal. For example, only 10 battery discharge when the two of them the battery voltage is 2.8 V, four of the battery voltage is 3.2 V, four is 3.4 V, now the overall voltage is 32 V, we let it continue to discharge work till 26 V. In this way, the two 2.8 V battery is lower than 2.6 V in the discharge condition. Lithium battery discharge is equal to scrap. On the other hand, with the overall way to control the charging voltage to charge, also can appear overcharge. Such as the above 10 battery charging voltage condition is at that time. Overall voltage to 42 V when the two 2.8 V battery is in a state of "hunger", and rapid absorption power, will be more than 4.2 V, and more than 4.2 V battery overcharge, not only because of the high voltage to produce scrap, even dangerous, this is the characteristics of lithium power battery.

The lithium ion battery of the rated voltage of 3.6 V (some products of 3.7 V).Fully charged when the termination of charging voltage related to battery anode material: 4.2 V for graphite anode materials; Anode material for coke 4.1 V. Different internal resistance of the anode materials are also different, coke anode resistance slightly larger, its discharge curve also slightly different, as shown in figure 1.Commonly referred to as 4.1 V lithium ion battery and 4.2 V lithium ion battery. Now use the most is 4.2 V, the termination of lithium ion battery discharge voltage of 2.5 V to 2.75 V (battery or termination of the discharge voltage, voltage range is given the parameters is slightly different).Below terminate discharge voltage continue to discharge called discharge, discharge the battery will be damaged.

Portable electronic products with battery are a power source. With the rapid development of portable products, all kinds of the dosage of the battery, and developed many new type of battery. In addition to all familiar of high-performance alkaline batteries, rechargeable nickel cadmium battery, nickel metal hydride batteries in recent years, have the development of lithium battery. This paper mainly introduces the basic knowledge of the lithium battery. Including its features, main parameters, the type, application scope and the significance is using matters needing attention, etc.

Lithium is a kind of metal elements, chemical symbol for Li (the English called lithium), is a silvery white, very soft and lively metal chemical performance, is the lightest in the metal. It besides used in atomic energy industry, can manufacture special alloy, special glass (TV screen glass) and lithium batteries. It is used as the battery in the lithium battery anode.

Lithium-ion batteries are divided into two categories: not charging and rechargeable ones. Non-rechargeable batteries as disposable batteries, it can only be chemical energy into electrical energy at once, can't electricity revert to chemical energy (or reduction performance is poor).The rechargeable battery is called secondary battery (also known as the battery).It can transform electric energy into chemical energy storage, when using, and then convert chemical energy into electrical energy, it is reversible, such as the main characteristics of electricity chemical energy lithium batteries.

Poach portable electronic products required size filial piety light weight, but the size and weight of the battery compared with other electronic components is often the biggest and the heaviest. Think that year, for example, "big brother" is quite "thick and heavy", today's cell phone is so light. Has played an important role in cell of improvement is: the past is nickel cadmium battery, is now a lithium-ion battery.

The biggest characteristic of the lithium battery is higher than the energy. What is the specific energy? Refers to the unit weight than energy or energy per unit volume. Specific energy with Wh/kg and Wh/L. Wh is the unit of energy, W is a W, h is hours; Kg is kg (weight unit), L is rising (volume unit).Here take an example to illustrate: 5 rating of the nickel cadmium battery voltage is 12 v, its capacity is 800 mAh, the energy as 096 wh (12 v x 08 ah).The same size 5 lithium - manganese dioxide battery rated voltage is 3 v, its capacity is 1200 mAh, the energy as 36 wh. Both the volume of a battery is the same, then the lithium - manganese dioxide battery than energy is 375 times of the nickel cadmium battery!

Section 5 about 23 g nickel-cadmium batteries, lithium and section 5 - about 18 g heavy manganese dioxide battery.- section lithium manganese dioxide battery is 3 v, and 24 v two nickel-cadmium batteries. So using lithium battery cell number (make less portable electronic product volume reduction of filial piety weight), and long working life of the battery.

In addition, the lithium battery has a stable discharge voltage, wide working temperature range, low self-discharge rate and long storage life, no memory effect, and pollution-free advantages.

Rechargeable lithium batteries

Non-rechargeable lithium batteries have a variety of, at present commonly used lithium - manganese dioxide battery, lithium thionyl chloride battery and lithium battery and other compounds. The two most commonly used before only introduced in this paper.

1, lithium manganese dioxide battery (LiMnO2)

Lithium - manganese dioxide battery is a kind of anode for lithium, manganese dioxide as the cathode, and USES the organic electrolyte of disposable batteries. The main characteristics of the battery is high battery voltage, rated voltage is 3 v general alkaline batteries (2 times);Terminate discharge voltage is 2 v. Larger than the energy (see the example above);Discharge voltage stable and reliable; Has good storage performance (more than 3 years storage time), low self-discharge rate, self-discharge rate of 2% or less (years);Working temperature range - 20 ℃ ~ + 60 ℃.

The battery can be made into the shape of the different ways to meet different requirements, it has a rectangular, cylindrical and button (button).The diameter of the cylinder also has different size and height. Here, everyone is familiar with the # 1 # code size (D), 2 (C) size code and 5 # main parameters of the code (size AA) batteries.

CR is expressed as cylindrical lithium - manganese dioxide battery; Five digits, the first two said the diameter of the battery, after three means with the height of a decimal places.CR14505, for example, its diameter is 14 mm, height is 505 mm (this type is common).

Here would like to point out different factory production of the same model battery parameters may be some difference. In addition, the standard of discharge current value is smaller, the actual can be greater than standard discharge current, discharge current and continuous discharge and the discharge current pulse discharge permission is different also, battery factory provide relevant data. For example, force and power supply company's biggest CR14505 given continuous discharge current is 1000 ma, maximum pulse discharge current of 2500 ma.

Camera is used in most of the lithium battery is lithium manganese dioxide battery. There will be a camera that is commonly used in lithium - manganese dioxide battery listed in table 2, for your reference.

Button (button) battery size is small, the diameter of 125 ~ 245 mm, height is 16 ~ 50 mm. Several kinds of commonly used button cells are shown in table 3.

CR for cylindrical lithium manganese dioxide battery, after four digits of the top two for the diameter size of the battery, after the two to take the height of the decimal point size.CR1220, for example, a diameter of 125 mm (not including the number of decimal places), its height is 20 mm. The model representation is international.

This button cell is often used in the clock, calculator, electronic notebook, camera, hearing AIDS, electronic game machine, IC card, standby power supply, etc.

2, lithium thionyl chloride battery (LiSOCl2)

Lithium - thionyl chloride battery is the highest specific energy, the current can reach 500 wh/kg or 1000 wh/L levels. Its rated voltage is 36 v, at a moderate current discharge extremely flat 34 v discharge characteristics (flat can within the scope of 90% capacity to discharge, keep not change).Batteries can be in to 40 ℃ ~ + 85 ℃ within the scope of work, but when to 40 ℃ has a capacity of about 50% of the normal capacity. Low self-discharge rate, self-discharge rate of 1% or less), storage life is more than 10 years.

In 1 # code size (D) lithium nickel cadmium battery and 1 # - thionyl chloride battery than energy: a comparison of the 1 # nickel cadmium battery rated voltage is 12 v, capacity is 5000 mah.1 # lithium thionyl chloride of rated voltage is 36 v, capacity is 10000 mAh, the latter more than six times larger than the former.

Application considerations

These two are disposable batteries, lithium-ion batteries do not charge (charging are dangerous!);The battery is not short circuit between the cathode; Cannot be too large current discharge (more than maximum discharge current discharge);Battery used to terminate the discharge voltage, should be timely take out from the electronic products; Run out of battery, not squeeze, incineration and disassembly; Cannot be used in excess of the prescribed temperature range.

Due to the lithium battery voltage is higher than ordinary battery or nickel cadmium battery, don't make a mistake when using so as not to damage the circuit. Through the familiar types of CR, ER can know its type and nominal voltage. When buying a new battery, must according to the original models to buy, otherwise it will affect the electronic product performance.

Case study:

Recently some children for robot training, parents who still think of very forward-looking consciousness recognized the engineer background I would like to give me children develop.

Actually as engineers, it seems, is to use some tools and guest (similar to the arduino, raspberries pie this reduce the application development difficult development board), let the child contact with software and hardware in advance, and some control, sensors, relevant knowledge. But the children are very happy to participate. Because the children are at such a young age, their assembly, an intelligent robot really has a sense of accomplishment.

Children's play is very happy. But the real problem, because the present design is, directly by the lithium battery to the motor drive, steering gear, such as high energy consumption of the device for power supply. Play to the most happy time, found "a dead battery". Many children in the robot, after completing a job didn't turn off the power supply in a timely manner. Led to the "put".Finally, we produce a large amount of "scrap battery".

The page contains the contents of the machine translation.