Technology explanation of lithium batteries explosion news

Lithium battery in the application of life suddenly expanded, stems mainly from smartphones, dressing equipment, electric bicycles, and the wide use of new energy vehicles. Over the years, tips on how to use the battery, lithium battery explosion and other news are constant, but often contain a lot of misleading information. In this article, we will talk from the simple application of lithium-ion batteries to the complex application one by one.

To measure the battery performance is good or bad, has the following several important indicators:

A, charge and discharge rate: the higher the better

"C" to describe the size of the battery charge and discharge current special symbols.1 c discharge is 1 hour from full charge of the battery into the empty current size.IPhone6 battery capacity is 1810 mAh, so 1 c discharge current of the battery is 1.81 amp; The e6 electric car for use in each battery capacity is 200 ah, is this battery 1 c discharge current is 200 amperes. If a battery with a high rate discharge, usually emit less energy than low range.

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Different discharge ratio down the battery

From the above test result, the power battery USES 10 c discharge energy is emitted by under 85%, 1 c discharge using 20 c discharge energy emitted by only 1 c discharge under 70%.

Second, the charge and discharge cycles: the more the better

500 is the common value of lithium-ion batteries, according to the different material of lithium battery charge and discharge frequency range from 300-3000.The value of the specific meaning each factory may be slightly different, can be roughly interpreted as: as stipulated in the manufacturer's charge and discharge rate (for example, 1 C discharge charging 0.3 C; Each time from 0% to 100%, according to the loop), after a 500 - cycle, 80% of the battery capacity with the original. The relationship between charge and discharge times and habits is too big, we give some examples.

1, the influence of the charge and discharge intensity of cycles

Factory mark: every time from 0% to 100%, 1 C and 0.3 C, filling capacity attenuation to 80% after 500 times, this is the most rigorous test cycle, also can not so strict, see below

If every cycle of power from 25% to 75%, 1 C, 0.3 C, filling capacity attenuation to 80% after 2000 times

If every cycle of power from 50% to 100%, 1 c, 0.3, filling capacity attenuation to 80% after 1800 times

2, a pale imitation of life

Factory mark: every time from 0% to 100%, 1 C and 0.3 C, filling capacity attenuation to 80% after 500 times, is the most rigorous test cycle, also can not so strict, see below

Every time the cycle of power from 25% to 75%, 1 C, 0.3 C, filling capacity attenuation to 80% after 2000 times

Every cycle of power from 50% to 100%, 1 c, 0.3, filling capacity attenuation to 80% after 1800 times

You can see these two examples to charge and discharge of the smaller the ratio, the more conducive to improve service life; Shallow filling is also beneficial to improve service life.

Three, internal resistance: as small as possible

This parameter changing with load weight, temperature, etc. At any time, as the battery life decreases, internal resistance has also been gradually increased. Internal resistance, the smaller the batteries can be higher rate of charge and discharge, 18650 common battery internal resistance of around 50 m Ω, power type 18650 battery at about 15 m Ω. Want to know how need to use special equipment to measure the internal resistance, not ordinary multi-meter.

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Measurement of battery internal resistance of the tool

Four, battery consistency

Use the same materials, the production of the same battery on the capacity, internal resistance, charge-discharge curve consistency, the higher the better. Whether large-scale battery of battery pack that is critical, the bigger the battery pack for the higher consistency requirements.

The following pages to the difficulty of the shipment will be effected according to the application:

1, mobile phone, tablet, wear equipment in the lithium battery

2, laptops and mobile power of lithium battery

3, the lithium battery electric bicycle

4, lithium-ion batteries in electric cars

Introduce some knowledge respectively, this page is according to the size of the smallest battery.

I. mobile phone, tablet, wear equipment in the lithium battery

Why do you say this area is one of the most simple? Because of these devices is only a piece of lithium batteries, and basic it is the ternary lithium battery. Three yuan mean three elements: nickel, cobalt, manganese, this kind of lithium battery cathode material Li (NiCoMn) O2, not completely the same, according to the requirement of three elements of the ratio of adjustment.

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One, the charge and discharge rate

In the digital equipment used in the battery usually to this requirement is very low. You can hardly an hour take full charge of mobile phone use automatic shutdown? Nobody can design a life only 1 hour of digital devices. Can last at least 3 hours, so the battery discharge rate of around 0.3 C can meet the demand, the charging requirements often are low, usually 3 to 4 hours of digital devices everyone can accept, so on the charging to the battery request is about 0.3 C.

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Whether domestic or imported lithium batteries, such as Panasonic, Samsung, 1 c discharge is minimum specifications, digital devices are far below the battery industry to the requirement of battery discharge of common standards. Charging ratio and battery industry can be the basis of the current index on the same, if there is no special design generally don't have to worry about.

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OPPO battery flash filling characteristics, puts forward higher requirements on charging

Recent mobile phone industry appeared a special case, puts forward the characteristics of quick charge represented by OPPO, actually puts forward special requirements on battery manufacturers. For OPPO latest N3 VOOC flash promise 30 minutes filling full of 75% of the battery, the charging current balance is 1.5 C, was 10 times higher than normal cell phone battery charging rate, also your sense of N3 sell 3999 yuan, at least the battery will be one, two times more expensive than ordinary ones.

Second, charge and discharge cycles

Digital devices, mobile phone is high strength products, we calculated on a day filling, life cycles is 500 time is 500 days, this is right? Is out of the terms of use, so is wrong. The cycle of 500 times refers to 1 C discharge, charging 0.3 C under continuous loop 500 times, 80% of the battery capacity with the original. But we usually use mobile phones, 1 C discharge rate is far less than is often between 0.01 C to 0.01 C. So cycles can usually have 80% charge remaining after 700 times, this has been 2 years time, mobile phone is almost out of date. Apple design of smart in this aspect, it intends to do not use the big power battery, can not only retain the advantages of lightweight, but also because after 2 years you are bound to change generation iPhone, why spend more cost on the battery? As for some people feel life much less a year, also have reason, after analysis.

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Keep 100% of electricity is not good

Other digital devices, such as tablets, battery charging cycle is long, but also sometimes found in less than 2 years of life obviously decreased, the reason is explained, the full article you will know.

Third, the battery internal resistance

No special explanation.

Four, battery consistency

No special explanation.

II. The notebook computer and mobile power of lithium battery

Laptop batteries specifications common core 4, 6 core, 8 core is what mean? This refers to the number of 18650 batteries, 8 cores, for example, there are two kinds of combination way, is a string of 4 and 2, a series of 2 and 4, according to specific use what kind of notebook makers voltage conversion circuit design, shape and battery storehouse.

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Four core notebook batteries

This statement can also describe the mobile power supply, commercial brands of mobile power supply capacity of 10400 mAh useful products is 2600 mAh by section 4 18650 batteries in parallel. Due to the Samsung SDK in order to take the Chinese market, for large orders taken at a low price, even at a loss to sell 1 $/, so a lot of big brand mobile power supply manufacturers like to use this kind of cheap and good quality batteries, but also because of single capacity is 2600, so the mobile power supply capacity is 2600 mAh often multiples: 5200 mAh, 7800 mAh, 10400 mAh.

One, the charge and discharge rate

New laptop battery electric light rare 1 hour, so are already enough to them, 1 c discharge rate charging request is not high also, such as laptop battery in 3-4 hours with everybody can accept everything. But for mobile power supply requirement for battery charging and discharging rate is lower, the lowest for almost all digital devices.

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Millet 10400 mobile power internal structure

At the current market in 10400 mAh mobile power supply (3.7 V), maximum output current is 2 a (5 V), also be in the maximum current takes 3.7 hours to electric light, meet 0.3 C discharge rate as long as enough. Of the specifications of the charging ways, usually is 10400 mAh equipped with A 1.0 A input port. This charge ratio is only 0.13 C. This is why mobile power supply inferior products much more special, even if it is regular vendors can buy battery market performance in the low (note that low performance and poor quality is not equal, but still highly correlated) products used in mobile power supply, but also can meet the specification requirements.

Second, charge and discharge cycles

Laptop and mobile power at a much lower compared to mobile phone use frequency, up to three days to charge their mobile phone, but the mobile power and notebook, on average, often can not complete a charge and discharge all week, so, just make sure charge-discharge life can hold 50 times a year. The worst of the worst for mature lithium battery can also provide the cycle life of 300 times, the number of people using laptops and mobile power supply is normal use 6 years enough.

And we tend to use less than so long to update, so mobile power supply in the industry, in particular, the actual use of light load and low frequency cycle count, it's hard to perceive the product quality. Some unscrupulous vendors can use the worst batteries, even the mechanical and electrical core used in mobile power supply. Split may be once upon a time in the other equipment, mechanical and electrical core has been loop 400 times, according to the life there is 100 times will be eliminated, and 100 times is enough for the mobile power on two years, so recycling buy mobile power supply it to won't someone found.

Relative mobile power supply, the original laptop battery batteries are international companies. But we also often find someone bought laptop around less than 2 years of battery life is greatly decreased, what reason is this?

Remember back when it comes to tablets using cycle is not frequently, but some also can appear 1-2 years, battery life is a dramatic drop in? In fact they are caused by the same reason: improper battery saving.

If you often have no matter to put the battery, or charging line had been inserted on the device, it always maintain the highest power, battery capacity can decrease quickly. This involves the structure of lithium-ion batteries.

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Lithium battery internal diagram

Lithium-ion battery anode is composed of metal oxide containing lithium ion, the cathode is usually composed of graphite crystal lattice, mobile charging lithium ion to graphite end, eventually breaking through composed of graphite stable lattice, gaining momentum. Can accommodate the crystal lattice of the lithium ion, the more the more lithium ions can move, the bigger the battery capacity. Long-term full electric storage is the main influence of the number of lithium ion can move, because after full recharge the battery voltage of 4.2 V, maintain high voltage to the electrolyte and anode are some reactions occur, the batteries are the reaction under the conditions of 3.0 V to 3.0 V are happening, but very weak. This reaction generated the passivation film on the electrode, the higher the voltage film is thicker, the thicker the film can be moved to the cathode of the less number of lithium ion into graphite lattice. So is the battery capacity attenuation on macro performance.

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Negative "small house", composed of graphite for lithium ion go out

What is "long-term"? It seems to me seven days is enough for the bad effects. How bad is it? Here is an example, the play of this people have 2 pieces of specifications as new ternary lithium battery materials A and B, bought in June at the same time deposit, A 30% deposit, SOC B with 100% deposit, three months after the test battery capacity, A capacity of 98% for the first, B capacity of 60% of the original. Yes, is so bad, so your laptop batteries often maintain high voltage for a long time, after a year life sharp decline is not uncommon. Mobile phones are the least likely to encounter long-term full charge storage devices, because even if full of, also have been using, within a few hours voltage down. But the phone occasionally encountered this problem, such as a full charge after shutdown, there is no electricity at this moment, the battery has been to maintain high pressure, maybe a week after you open the box, batteries have bulge.

The right thing to do is to charge 30% to 30% of electricity, and long-term preservation.

Third, the battery internal resistance

No special explanation.

Four, battery consistency

Barrel effect is how much water a bucket can hold depends on the shortest that the height of the wood in the siege of wood, in the lithium battery pack up to describe the better consistency. Bad battery consistency of transmitte several more battery influence is greater.

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Notebook six-cell battery

Suppose six-cell battery in figure 3 18650 capacity drops faster for some reason, capacity is only 75%, soon they 6 is connected in parallel, so the third battery discharge process will be the first to discharge termination voltage, so regardless of the other five battery has no electricity, discharge the battery pack will be stopped. When charging, too. Results five other battery don't have any problems, also followed a problem 18650 synchronization charge and discharge, the battery from outside is serious capacity attenuation. In fact there is only one problem. This is the embodiment of the consistency of the importance of battery.

III. The lithium battery electric bicycle

Luyuan, new day brand from 2010 began to enter into every family, but then most of the electric vehicle are lead-acid batteries. From 2012, adopt the lithium battery electric bicycle began appearing in the specifications of the common voltage is 36 v, 48 v, volume 8 ah - 12 ah. The kind of electric bicycle with pedal if using 48 v12ah lithium-ion batteries, pure electric range of 50 kilometers.

One, the charge and discharge rate

The bicycle has no special request, for charging common charging ratio is between 0.1 C to 0.1 C, battery plant easily, but slightly higher on the discharge rate, to meet at least 1 C, it has less pressure for battery factories. But there is a type of electric scooters, adopts pedal motorcycle appearance, can even more than 100 km/h, the car to the requirement of battery increase to 2 c - 3 c, so if you are assembling the high-performance electric vehicle, the choose and buy when the battery to calculate well.

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Lithium battery in the arrow

Firms often don't have to worry about batteries, their distribution of batteries in general there are three types: Lithium iron phosphate batteries, the ternary lithium battery, battery power three yuan. Their highest discharge rate respectively is: 2 C and 1.5 C, 10 C. You can increase the capacity of the battery to improve corresponding 1 c discharge current.

Second, charge and discharge cycles

lithium iron phosphate battery life of about 2000 times, around 800 ternary lithium batteries, and power ternary lithium electricity is about 800 times. But due to the electric bicycle is often not in single cells, barrel effect cause group first appeared on the capacity of the fault, after the meeting on time in advance, about 1/4 to 1/2 of monomer life cycle.

Of course, this also and habits. Just said all the rules here, because we here involves another kind of cathode material: lithium iron phosphate, so Nathan said unto David.

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The use of the modified power lithium iron phosphate battery pack

The energy density of the lithium iron phosphate is 40% lower than that of ternary lithium electricity, the same energy of lithium iron phosphate battery large volume, weight heavy, advantage lies in cycles, good maintenance. Or what you just said conditions, for example, the ternary lithium electricity is full deposit for 3 months, 60% of battery capacity attenuation to the original, but in the face of lithium iron phosphate deposit such harsh conditions also can keep 90%, while also lost, but far from ternary lithium electricity so serious.

This reason, and most of the energy lithium iron phosphate (85%) were focused on the 3.2 V voltage, although the cut-off voltage of the battery is 3.6 V, but within the range from 3.6 V to 3.2 V stored energy is less than 1% of the total energy, even after the full, put a few minutes the voltage will be back to 3.2 V. So the lithium iron phosphate automatically maintains low voltage stress. Not easy to form passivation film.

Third, the battery internal resistance

No special explanation.

Four, battery consistency

The consistency problem is more important, the monomer in use electric bicycle battery roughly two categories:

1, small single cells, or 18650 batteries, the capacity of 2.2 2.6 Ah, Ah - each battery monomer number 200-500.

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Using small battery monomer composition, group 120 v100ah battery pack

2, large monomer battery capacity is commonly between 20 ah - 40 ah, each battery monomer quantity 15-30.

We 72 v40ah battery pack, for example, if using small monomer battery, you need 20 and 19 and 380 380 battery. Every 20 head-tail for a, 19 battery charge and discharge at any time within the 0.02 V, the voltage difference require sounds demanding, but actually not difficult like imagination, because of 18650 battery technology is already very mature, with a batch of battery has a very good consistency.

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Big monomer lithium iron phosphate batteries, all kinds of specifications

If big monomer battery using 20 ah, you need 20 series 2 and the way, about 40 large monomer battery, as long as the 40 work synchronization was no problem, generally after the big monomer battery group on the consistency problem of smaller risk. Unfavorable factors also have, if it's big monomer battery, lithium iron phosphate consistency will be far worse than the ternary lithium electricity, so the battery pack need to add an automatic balancing circuit, which a judge at the end of each charge the battery to charge more for a while, to solve the poor consistency of lithium iron phosphate is weakness.

Consistency problem has risen to an important position here, but not to the extreme.

IV. The lithium-ion batteries in electric cars

Lithium batteries of electric cars is the most complex applications, because the battery under high power charge and large capacity storage, high frequency use, driving for a long time, such as demand, batteries are used in the normal big high specification products, eliminate the waste batteries in electric cars are often fitted on electric bikes, still have a place (of course, this belongs to profiteer behavior), usually is eliminated to energy storage power station is used to store wind and solar power.

One, the charge and discharge rate

According to different vehicles, difference is very big, known as BYD qin took 152 of the single capacity of 26 ah lithium iron phosphate batteries, discharge voltage curve integral to get the total energy of 10.5 KWh, the maximum power of the motor is 110 kw, Qin qin battery requires 10 c discharge rate. Pure electric vehicle e6 BYD another passenger car battery has the largest battery capacity: 63 KWH, so in order to achieve higher power does not need the battery discharge rate is very high, the e6 battery discharge rate is 1.5 C. Pure electric vehicle battery capacity of the largest bus, such as BYD 13.8 m long electric coach K9, battery capacity of 324 KWH, because the battery capacity is huge, for 180 kw of power battery discharge ratio you just need to 0.5 C.

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BYD K9 electric bus sell to Israel

And some a plug-in hybrid car, only 1.5 KWh battery capacity, but the peak power up to 30 kw electric motor, is the car used in the battery discharge rate may be 20 C, compared the application scenario of mobile power supply for more than 100 times larger 0.2 C.

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The camry hybrid version, you need to use power battery, discharge rate is higher

Pure electric vehicles are mostly set up fast and slow filling two kinds of charging ways, full of quick charge the slowest 2 hours, so the charging ratio is 0.5 C. And more exaggerated, such as musk tesla's bosses hope that the next generation of tesla charging time can be reduced to 10 minutes, so the charging rate must be at least 6 c.

Second, charge and discharge cycles

The design of new energy vehicles, the battery life longer than the vehicle life. So battery life guarantee vehicles moving at least 300000 km, for the most part it has been released by pure electric and hybrid cars. In the e6, pure electric range of 300 km, battery capacity of 63 KWH, calculate by a 2000 - cycle life, it is 600000 kilometers (actual it is slightly less than 600000 kilometers, think about why?)This is far more than the general owners demand for total mileage.

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The e6 the taxi driver

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Total length of more than 500000 kilometers of the e6

BYD started from 2010 in Shenzhen in the actual test run 850 e6 taxis, up to now there have been dozens of car mileage totaling more than 500000 kilometers, I once went to Shenzhen in July special probe e6 electric taxi, watching them is a set of battery from the factory has been used now, have met with a total mileage of 500000 kilometers of the driver, with his reputation guarantee, not only didn't change the battery, the battery life is no obvious drop, coincidentally, home of cars have been testing the driver car life, urban + + high speed under the condition of the whole air conditioning ran to the life without electricity, a total of 260 km.

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BYD all-electric e6

The emergence of new energy vehicles, pure electric vehicles, in particular, in addition to leading the industry in BYD 5-7 years, other car companies own brand products are released four years ago and informed the development of new energy and developed, are shelves to throw away the engine and fuel tank, fuel car into the motor and battery conversion. Characteristic is under the condition of life in 150-180 km (because will certainly to 150 kilometers, 150 kilometers on the national and local subsidies are a step!)And these car real life summer often in 120-150 km, the winter of 100-120 km. For these lineages not pure electric vehicle battery cycles is enough?

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Lithium iron phosphate batteries

This to the specific situation, if is to use the lithium iron phosphate batteries, then 120 kilometers by 2000, there are 240000 km range, in addition to all this due to the use you not throttle really, every time and every time discharge from 100% to 0% full, so more than 2000 cycles is also very normal, it also ensures that the car battery can last longer than the vehicle at least.

But another adopted ternary lithium battery was a bit suspension of pure electric vehicles, due to China's new energy vehicles currently though useful do batteries ternary lithium electricity, but no one to buy, after long time use of statistics is more impossible. But there are precedents abroad, and is a very famous example, Nissan LEAF (LEAF) is one of the largest pure electric vehicles, sales in the world from 2011 to now, has sold 130000 vehicles, sales does not mean that the quality is good, mainly because of cheap, Europe and the United States has been a pure electric vehicles since the listing of the lowest price, $or RMB 180000.

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NEC modified manganese acid lithium ternary material 35 ah battery, the morning car use

And after 3 years of use this car battery range by obvious concentrated outbreak. The car with the NEC modified manganese acid lithium battery (also belong to the ternary lithium batteries a broad categories, only the positive ratio of material and doping slightly adjustment), soft bag single 35 ah. Although Nissan may not acknowledge the problem, but Taobao shop sales of teardown can explain lithium-ion batteries, the league of electric vehicle battery in stores in the list, no matter the business in Shenzhen, Guangzhou, Wuhan, Changsha, Beijing, Dalian, they all have the same kind of split: mechanical and electrical core NEC modified lithium manganese acid 35 ah triple double soft bag. Some of the monomer looks very new, very ears are not shear welding marks. They actually come from Nissan leaf electric cars, has problems of its own car number, factory after again accused of lax, then split massive outflows, mechanical and electrical core were merchants chariot sell DIY electric motorcycle people use.

The leaf of the root cause is that it USES the battery cycle times, there were fewer than lithium iron phosphate should be around 800 times, if you are interested in can be Baidu search "the leaf cell aging too fast", or on Google search "Nissan leaf battery capacity loss", you will see the problem. Nissan also established for investigation and follow-up provides a replacement battery service, the price of a complete set of battery replacement for $5500.

Unfortunately the car is only another name came to China into the east wind of pure electric vehicles, Qichen - Chenfeng ", to borrow the new name got the national and local subsidies per car ninety-five thousand, the car at present domestic price 267800-267800.

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Nissan LEAF (LEAF) or east wind chill

Including morning breeze, the working condition of all the test range of 200 km under the pure electric vehicles are not worth buying, they are born at the beginning of the mission was to superior job, to get further opportunity to fuel cars. In 2010, faw, Beijing and other car companies didn't think of the new energy automotive strategy in 2014 has become an irreversible development direction, not to pay a few spelling change of pure electric vehicles to declare new energy vehicles national directory is fine. They even planned to develop a specially designed for electric vehicles also have to wait four years before, and they really have the research and development strength? Personally, I prefer a few years later, the car companies still rely on the introduction of the joint venture brand models to sell others research and development of pure electric vehicles, operating methods can refer to the leaf become morning breeze.

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BYD qin

All car companies except for BYD, BYD from 2003 acquisition of Qinchuan motors before spoiling for electric cars to do, not only motor, electric control, battery research and development production themselves, and even the source of anode materials are: mine, went to fight for control, the world's second largest lithium ore 49% stake holders is BYD chairman Wang Chuanfu cousin. There are several mines. Literally speaking, both all-electric cars and plug-in hybrids, BYD products level at least ahead of other domestic automakers 5-7 years, even to the world, if only to discuss the new energy vehicles, the motor, electric control, battery that the three most important parts of BYD is also one of the top level.

For BYD new energy vehicles is the enterprise survival products, new energy vehicles for other car companies is a matter of how much subsidies..

Third, the battery internal resistance

No special explanation.

Four, battery consistency

Due to many car companies have adopted the lithium iron phosphate battery, the battery monomer capacity can reach 200 ah, so don't see car battery capacity big, monomer amount is not too much. But there are exceptions, that is, tesla, Mode IS to use 18650 nca Panasonic battery, a total of 7623 knots, single section capacity 3.1 Ah, in 2011 tesla bought a total of 200 million such a battery, which is just enough to high production ModelS with version twenty-six thousand.

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If for a battery to the normal section 7622 remaining battery cannot successful use of all 3.1 Ah capacity, that the power system of this car is too failed, here we see the lithium battery on the consistency of the ultimate application. To ensure consistency, besides to Panasonic very strict request, tesla also made an expensive battery for battery management system, this system not only can monitor each section of the battery voltage and current, to achieve reasonable charge and discharge, and can also ensure that their temperature. Battery charge and discharge curves are consistent and battery temperature has much to do, tesla chassis covered with battery, different location of the battery temperature difference is very big, so in order to keep the charge and discharge curve is consistent, must first ensure the temperature of the 7623 cells, which depend on a two-way flow of liquid-cooled system implementation, the liquid of 50% water and 50% of ethylene glycol.

Analysis, according to industry professionals, tesla's battery management system, even produced in China, all costs are $6000 to $8000, 100-200 yuan compared to the electric bicycle battery pack with automatic balancing charge and discharge protection board more complex, after all, to control the number of batteries to rise to four hundred from seven thousand.

Lithium-ion batteries in electric cars, we spend far too much ink, this is because the situation here the most complex. Below we talk about common lithium-ion batteries.

VI. All sorts of rumors about lithium battery (a)

Rumor: bought new batteries will charge three times only be activated?

The nickel cadmium battery copied from years ago, the activation of the lithium battery was conducted in the factory, raw material and pulp, coating, slice, roll pressure, laminated, assembly batteries, baking, note the electrolyte, into, large current test, is done after activation. Ordinary people home also does not have this kind of equipment. This advice and even appeared in some brand mobile phone specifications, may be written instruction has been copying the old version, not found error.

Lithium battery when you will find that most power along the remaining 30% or so, this is the ideal battery factory inventory.

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Lithium battery activation process, this kind of equipment do you have?

Rumor 2: lithium battery with a photoelectric charge again?

This is nickel cadmium from 10 years ago, the battery has a memory effect, so be light again after filling. Before we put in filling percentage impact on life in an example:

Factory mark: every time from 0% to 100%, 1 C, 0.3 C, filling capacity attenuation to 80% after 500 times

Every time the cycle of power from 25% to 75%, 1 C, 0.3 C, filling capacity attenuation to 80% after 2000 times

Every cycle of power from 50% to 100%, 1 c, 0.3, filling capacity attenuation to 80% after 1800 times

Every time after two practice while only half of the electricity, but cycles a is four times that of before, one is 3.6 times as much as before, so the ability of whole life period release or 1 times more than the deep charge deep discharge method. This is the so-called "shallow filling is conducive to longevity".0% 100% belongs to deep charge deep discharge, is one of the most cost the life of usage. So increases with the increasing in charge mobile phone battery, don't go for always full charge, also do not often use automatic shutdown, so that the most beneficial to the battery life-span.

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This does not mean that the battery has no electricity

But also it is important to note that we use the cell phone, tablet automatic shutdown is not battery when 0% of the time, generally speaking mobile phone manufacturer design shut down automatically when the battery voltage is lower than 3.0 V, the actual below 2.7 V battery discharge will hurt the battery, 3.0 V battery when there is at least 5% of the remaining power, so even if used automatic shutdown also don't worry too much about the injury to the cells, but each time with such light also calculate accurate depth charge deep discharge.

Rumor three: phone while charging, cell phone will explode?

The basis of the rumors may be, it will cause the battery temperature is higher than only charging temperature. If the temperature would be higher still makes sense, because charging energy conversion efficiency is usually only 85%, the remaining 15% of the energy is the waste heat; Phone baseband chips also is in working status, also in fever, especially when a call on one side of the cell phone also put you in the face, the three factors have increased the temperature of the battery.

As a rumor, but if you bombed a week you should hear so-and-so colleagues to face, isn't it? So the truth is that only will cause the battery internal temperature, there is not a serious consequences.

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Rumor: four charging time not more than 12 hours, turning green after filling 1 hours to charge 10% more power?

In order to prevent the battery explosion, the industry is designed according to one over one billion level failure rate, but no matter how to control the process and the process, a single step all cannot achieve such a high safety degree, so use is two levels. Level 1 charger, battery protection board level. Each level guarantee is one over one hundred thousand of the failure rate can be achieved, so the two problems at the same time lead to battery explosion is one over ten billion.

Charger is designed so that side, using constant current charging, first within the electricity charge to about 75% in 4.2 V way of constant voltage charging, the current would drop slowly, because of the battery voltage increases current charger in the judgment, until the current is less than a certain value, such as 20 ma, then the green light.

Charger do next? It depends on what you use control chip for the charger. Decide what to do after the charger chip control schemes.

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Charge and discharge management chip in the charger

1, charging TI BQ2057 series chips, Linear LT1800 series is a seat completely shut off the charging circuit, so everyone here again placed 10 hours and has no influence on the filling.

2, charger continues constant voltage charging, and strictly control the voltage no higher than 4.2 V, there is no doubt that fill a few more hours, can increase power. But from the increase in the process of the green light to 4.2 V is less than 0.1% of the battery, it's no use.

3, Maxim of 1679 chip inside will also see in many phones, it adopts the pulse charging mode, press it to show a green light, the battery has 100% full, place an hour again, of course, it will not overcharge. That is not only a lot of the charger when the green light to stop, even refused to charge the phone itself into the current.

4, the charger to charge, but it's in bad current control, accidentally make a battery than 4.2 V, and continue to run up. What had happened, that when the voltage to 5 v is not far from the explosion, but in addition to the charger, battery side also has to protect, so garbage charger sell a lot, but not common battery explosion.

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Typical junk charger, don't buy it

Finally is a kind of typical garbage charger, if you are charging phone use this kind of thing, the inside of the mobile phone charge control chip can also be in full to cut off the current. But if you are take the battery out on this type of charger, it maybe will bulge, even exploded.

Rumor 5: night power grid voltage fluctuation is bigger, the lithium battery is delicate, so don't charge at night?

If so, the broken every night all over the world millions of cells, and early to rise up on see, battery scrap? Actual situation from 220 v to 5 v voltage electric, again from 5 v voltage transform to recharge the battery voltage, after several middle voltage transformation step, every step of the output voltage is qualified. Even if 220 v side again how fluctuations will not affect the battery voltage. The rumour of a change in a scene is: typhoon megi landed in Fujian, so please Beijing residents away from the park and the moat waters, so as not to endanger the safety of life. Look is a very compassionate person, actually there a typhoon again big, the moat will not so big wave.

Myth: lithium polymer batteries safer than 18650 batteries?

That makes sense, explosion is divided into two categories: one is inside the battery short circuit temperature after a sharp increase in combustion, explosion; The second category is the gas inside the battery, no combustion, gas burst housing. Polymer batteries is largely avoided the second cause of the explosion, polymer batteries not enclosed in a fixed volume, if use undeserved, electrolyte batteries produced gas bulging, sometimes broken skin, gas leaks out, due to the fault battery failure, while also but avoid the explosion.

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The same model polymer battery normal left and right of, bulge, but failed to explode

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Polymer batteries have blow up space

18650 batteries also have a safety valve, once the gas pressure increases to a certain degree of the valve will cut off the circuit, so can't continue to use the battery, there is no voltage, but a lot of domestic 18650 valves is not reliable, so compared with the properties of polymer can beat, 18650 batteries is more likely to explode.

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Steel shell does not have the space, discharge gas explosion

And using the ternary material of lithium battery as long as the anode material exposed to air, contact with the oxygen and water, burning are easily happened, I also believe that Panasonic, Sanyo these brands will not only domestic waste batteries combustion, explosion and then seen a lithium battery explosion of science programs, found that as long as the pierced 18650 batteries will burn them all. Import high-grade and domestic only has differences in safety valve led to import more secure.

Myth: power shows why not?

Mobile device's battery shows there are 2 different way, one is an apple iphone 3 gs had started to use the coulometer test power, is the charge quantity statistics to flow through, so the accuracy is high.The other is a fitting way to judge, great error in this way.

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The ternary material lithium battery discharge curve

This is a capacity of 2600 mAh lithium batteries ternary material, 1 a discharge, the discharge curves under 25 ℃, the vertical axis is the voltage, the horizontal axis is time. Consistency in the production of mobile phone purchase same type batteries, good battery discharge curve is almost the same, the voltage corresponding to the battery percentage point of the record down, can form a voltage - electricity 】 【 table, as long as the measurement of voltage, can know the remaining power. This is the principle of voltage fitting. But we will find that A section of the voltage change with power is more noticeable, section B power changes A lot, but not how to change the voltage. So section B of electricity display error is more easily. This is one of the causes of error.

Another reason for greater influence on error: temperature.

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The influence of temperature change on the power measurement error

The same battery different temperature lowering electricity curve, the above is just the battery discharge curve under 15 ℃ and 25 ℃, a temperature corresponding to a line, two green dot is the voltage of the same point, by just CRT to display power, voltage - electricity 】 【 will cause an error of 10%, then you said it doesn't matter, can be in 5 ℃, 15 ℃, 25 ℃ and 35 ℃...Test under different temperature after several corresponding table, display power before temperature measuring, and judgment with which a voltage - electricity 】 【 CRT, the problem is not solved? Yes, it really can further reduce the error, but I would say that the change of the discharge curve also, along with the change of load also had considerable also varies with the location of the battery's life cycle also has a small change? To display power, don't you want to make a 【 temperature n * m kinds of load * q - electricity 】 something kind of life table? Almost got, not doing the experiment. So low-cost mobile devices are not willing to use coulombmeter, also just keep the digital display, cost is high and is not allowed, simply set up four LED lights, each lamp represents 25% power, tube he must not.

The full text summary:

This article does not say too full, such as lithium iron phosphate batteries at low temperature (10 ℃) capacity by half, can't even under - 30 ℃;Why can't the lithium battery charging less than 0 ℃;How after charge and discharge the battery is damaged; Mobile phone battery bulge is battery quality problem and so on. But this article has a long, later free again write...

The page contains the contents of the machine translation.