01
The invention of lead-acid batteries
In the southern half of the far side of the Moon, there is a large crater formed about 3.9 billion years ago, which was named "Plante Crater" in 1970, also known as "Plante Crater".
The crater is named after the French physicist Raymond-Louis Gaston Planté (1834-1889), the inventor of lead-acid batteries who made outstanding contributions to the modern automotive industry.
Gaston Plante was born in the Pyrenees-Atlantic province, in the lower leftmost corner of the modern French territory, belonging to the Aquitaine region, which historically followed Eleanor of Aquitaine into the British territory and then returned to France.
Gaston Plante was a genius, attending the Sorbonne university as an undergraduate, earning a Bachelor of Arts degree at the age of 16, a Bachelor of Science degree at the age of 19, a Master of Science degree at the age of 21, and a professor of physics at the National Academy of Arts and Crafts in Paris at the age of 26.
Is it amazing to become a professor of physics at the age of 26? No, because Gaston Plant invented the Lead-acid battery at the age of 25, and his invention of the commercial rechargeable battery was popularized worldwide on top of the car invented by Mr. Carl Benz.
Feats higher than the sky are also normal to be carved on the moon.
02
Promotion of lead-acid batteries
Lead-acid batteries are "one" secondary batteries, but also "first" secondary batteries, because the secondary batteries before the lead-acid formula were not officially mass-produced, and the lead-acid formula was improved by the French chemist Camille Alphonse Faure (1840–1898) to achieve mass production, and the large-scale mass production enterprises came from the Luxembourg engineer, inventor and entrepreneur Henri Owen Tudor( 1859-1928), Mr. Tudor (this surname can also be translated as "Tudor") improved lead-acid battery actually took 5 years and 2 months to scrap, solving the problem of the short life of the secondary battery.
The first thing after the mass production of lead-acid batteries is to provide temporary lighting power for the train car body that stops at the railway platform, and at the same time, a considerable part of it is used to manufacture electric vehicles, which are pure electric cars powered by Tudor lead-acid batteries.
The picture below shows the label on the battery made by the Tudor Battery Factory in Russia, when Eastern Europe and Western Europe were not separated, and the kings and emperors of Europe were related until November 1917, when the cruiser Aurora sounded a cannon and the revolution came.
Before the mass production of secondary batteries, all electric vehicles were only experimental products, because the primary batteries they used were scrapped when they ran out. The arrival of lead-acid batteries announced the birth of power batteries, because it can really drive a car to travel tens of kilometers, which is an alternative power for cattle and horses.
Early internal combustion engine automotive products did not have an electrical system, and the start was solved with a crank (which is now a walking tractor "key"), the horn was solved with a bell, and the headlights were directly powered by the internal combustion engine.
In 1918, the predecessor of AMC, the Hudson Motor Car Company, introduced 6V voltage into the assembly sequence of production vehicles, and gradually introduced the assembly of on-board lights and starters, and the production of lead-acid batteries began to increase. After entering the 50s, the American large V8 engine with 6-8L displacement made the waist and legs of the 6V voltage system sore, and the budget engineer connected two 6V lead-acid batteries in series, which became a 12V lead-acid battery, which has been used to this day.
Of course, 12V is not the only voltage of lead-acid batteries, the diesel engines of some trucks are very large and heavy, you can connect two 12V into 24V batteries in series, you can also connect three into 36V.
03
Principle of lead-acid battery
Why can lead-acid batteries only be used to drive golf cars, not as a powertrain for passenger cars?
It is not impossible, the Nissan Tama (1947) in the picture below uses a lead-acid battery to drive, but the top speed is only 34km/h, the endurance is 65km, and there is a pulley group under the lead-acid battery pack under the car, which can be relatively easily moved out of the battery with photoelectric and plugged in with full power.
The reason is that the energy density of lead-acid batteries is very low, even after a century and a half, the current lead-acid batteries can only do about 35-40Wh/kg (about 80-90Wh/L), too heavy, too little power.
Take our commonly used 12V lead-acid battery, the capacity is only 0.6-1.2kWh (the general luxury brand of large and medium-sized cars only use more than 1kWh), the output power is only 5kW (of course, there is more than 10kW of cold start power), starting the gasoline engine is enough, listening to songs in the car can also listen to half an hour, but the air conditioner can only last for tens of seconds to stop the compressor, because this is not a deep cycle battery.
The industrial chain of lead-acid batteries is extremely mature, and the structure is very simple. In a fully charged state, the negative plate of the lead-acid battery is lead, the positive plate is lead dioxide, and the electrolyte solution has a higher concentration of aqueous sulfuric acid, in which most of the chemical energy is stored.
If overcharged, part of the water will be electrolyzed into oxygen and hydrogen, at this time it will be refilled with pure water to replenish the electrolyte.
When discharged, the positive and negative plates will become lead (II) sulfate (PbSO4), and the electrolyte loses sulfuric acid to get water and electrical energy is released.
Lead-acid batteries are full of liquid, high density, large weight, energy density is urgent, but its stability is particularly good, the number of cycles is also more, the global industrial chain is mature, the cost is relatively low, so it is used in many industries, such as:
1, starting battery: used in the car starter part, than the same size of the deep cycle battery is lighter, longer service life, generally can stand 3-5 years.
2, power battery: two-wheeled and three-wheeled electric vehicles prefer to use, the new national standard stipulates that four-wheeled electric vehicles to use lithium batteries, in addition to golf carts, electric forklifts and other uses. The power battery must be a deep cycle battery, and the energy storage potential must be tapped.
3, energy storage batteries: energy storage batteries used in RVs and ships are designed to have a larger capacity than the starting battery, but not as deep as the deep cycle battery charge and discharge, and the life/energy storage is between the two.
4, backup power supply: uninterruptible power supply UPS, communication base station, alarm also use lead-acid batteries as energy storage, and are gradually replaced by lithium-ion batteries. This kind of battery attaches great importance to the number of cycles, and the longer the life, the better.
This section ends with a very funny video. In a country that has only achieved industrialization of 0.5, the uncles will actually renovate lead-acid batteries with their bare hands, which is really fierce.
The old eight ancient method refurbished dump truck batteries, the materials from beginning to end their own control. Artificial pre-planting irrigation of sulfuric acid
04
EFB vs. AGM Technology Genre Controversy
In the old days, cars only had tape drives and radios inside, but even then you often had to bring a "river dragon" to prevent weak car batteries from falling off the chain. After entering the 21st century, the electrical equipment on new cars (including audio-visual entertainment systems, active safety systems, seat heating massages, etc.) has increased sharply, and the engine self-start-stop system has gradually become the standard item of mainstream passenger cars, and the on-board 12V battery must also be upgraded synchronously to adapt to this era.
Of course, 12V lead-acid batteries have changed somewhat since the 1990s. The previous on-board battery only needs to start the heat engine after the big job is not done, and now the 12V battery must often make efforts to cope with the self-starting and stopping conditions in the urban congestion environment. Turning off the engine at the right time, such as shutting down when queuing in front of a red light, or turning off the vehicle with a taxi function in advance before reaching the red light position, can improve the thermal efficiency of the heat engine to a certain extent, save fuel, and reduce emissions.
In Germany alone, greenhouse gas emissions have already been reduced by 40% by 2020. Carbon emission targets have had a huge impact on the auto industry, and vehicle emissions are considered a major source of pollution emissions, even if the auto industry does not agree with such accusations. For the general public, emission-free electric vehicles are still a bit far away (not the main body of sales for the time being), and the most feasible energy-saving and emission-reduction solution today is the engine self-start-stop technology, corresponding to the new 12V lead-acid battery - EFB battery (Enhanced Flooded Battery) and AGM battery (Absorbent Glass Mat Battery).
Let's start with cheap EFBs. EFB is a reinforced liquid-rich lead-acid battery, and the structure is not fundamentally different from the old lead-acid battery. The old battery mentioned here refers to the SLI battery (Start Lighting Igniton) and the Alternator Management System(Alternator Management System), both of which are not compatible with the self-start-stop system.
EFB's "Enhanced" refers to the battery optimized for charging limits and cycle life, in order to cope with the high frequency high current charge and discharge that comes with frequent self-start-stops, because each self-start-stop action of the engine will correspond to a high current surge.
When the engine is turned off, all the on-board electrical systems just mentioned will be powered by a 12V lead-acid battery alone. If you install a set of old lead-acid batteries from the 90s, it will twitch to death because neither the power nor the capacity can meet the power needs of modern models. This old battery is not unable to install, but installed on the waiting to be scrapped by the on-board electrical system, its aging speed beyond your imagination, so the current passenger car minimum also has to have an EFB battery.
When you buy medium and large vehicles, luxury brand models, performance models, etc., you will find that an AGM battery is placed in the cabin. AGM means "Absorbent Glass Mat", using a glass mat separator that absorbs acidic solvents and prevents leakage.
The second difference between AGM and EFB is the degree of compression of the lead plate. Because the AGM lead plates are compacted and pressed more tightly, the battery is more earthquake resistant and also helps to promote electrochemical reactions, so the cycle life of the AGM battery is higher than that of EFB, and it can be charged and discharged normally for a longer time.
EFB and AGM are the products of two different processes for starting wet batteries, and the principle is the same. When fully charged, the general open circuit voltage is about 12.8V, and if it is reduced to less than 12.4V, it will automatically charge.
Just now we mentioned that the SLI series battery does not support self-start-stop, so the charging curve of the SLI on the left side of the following figure is "start-consume energy - charge - flat", while the charging curve of the self-start-stop battery (EFB and AGM) on the right side of the following figure is constantly cycling "start-consume energy – charge – flat - kinetic energy recovery charge" these steps.
Compared to EFB batteries, AGMs are more chemically active and can withstand the high inrush currents of higher frequency self-start-stop and kinetic energy recovery systems.
Can I change an AGM for a car with EFB as standard?
The answer is: it can be used temporarily, but it ages faster.
Let's first understand the differences between EFB and AGM lead-acid batteries:
1, AGM is currently the strongest civilian 12V battery technology, the price is about 1.5 times that of EFB battery.
2, AGM theoretical life of 4-6 years, EFB theoretical life of 3-5 years, if the lead-acid battery is designed in the rear cabin (front engine scheme), because there is no engine day and night high temperature baking, the life will be longer.
3. AGM has no acid leakage, stronger cold start function, and stronger tolerance of high current surge.
It can be seen that EFB and AGM are basically the same in function, there is a difference in performance, and the cost performance is undoubtedly higher than EFB, but the model with standard AGM cannot be backward compatible with EFB for a long time, and the model with EFB can be upward compatible with AMG.
In addition, if you are like me, the last time the first thing to fasten the seat belt, the second thing to ignite, the third thing must be to turn off the self-start-stop system, then can you replace the waste EFB/AGM self-start-stop lead-acid battery with a lower-cost SLI battery?
Answer: No, because the power demand (load) of the on-board electrical system of modern automotive products is very high, even if the self-start-stop system is not used, it will reduce the demand for instantaneous large currents, and other on-board electrical systems are also very energy-consuming, and the old lead-acid batteries cannot support this big task.
05
Some frequently asked questions
How long does the A12V battery generally stop without power?
This indicator tests the self-discharge rate of lead-acid batteries, that is, the ability to maintain charge.
In theory, the self-discharge rate of lead-acid batteries is between 20-30%, that is, between 20-30% a month, but in practice it is far more than this ratio.
Under normal circumstances, a healthy 12V lead-acid battery can barely start after 30 days of standing, and it is a bit hanging after more than 30 days. If a car can't stand still for only 15 or even 10 days, it can't catch fire, then it is better to replace the 12V lead-acid battery.
What are the signs of B lead-acid battery fast flutter street?
1, the engine ignition is weak, and even the point is lit several times.
2. Press the horn without starting the engine, and the sound is weak.
3, some instruments have battery alarm lights, and some show the battery voltage.
4, when you go to maintenance, some dealers will help you measure the voltage with a meter, and then write it in the report.
5, after the cycle life is used up, the battery is finished, at this time we will say battery life EOL (End Of Life). In some cases, the battery is out of power during the driving process, that is, when it is open, the high temperature inside the cabin becomes the last straw that crushes the camel that the battery cannot charge, and the dashboard and headlights will be bright and dark at times.
Does the C48V hybrid still need a 12V lead-acid battery?
1, need, all current 48V light hybrid vehicles need 12V lead-acid battery.
2. The 48V battery generally adopts lithium-ion battery pack, which serves high-load components such as engine self-start-stop, air conditioning, electronic anti-roll rod, and air suspension.
3, 12V lead-acid battery is used to power door locks, anti-theft devices, audio and other low-load components.
The 12V lead-acid battery of the 4 and 48V mixed vehicles is still a consumable and needs to be replaced after several years of use.
Do new energy vehicles still need 12V lead-acid batteries?
1, need, even pure electric vehicles also need 12V lead-acid batteries.
2, when the 12V lead-acid battery is insufficient, the high-voltage power battery of the new energy vehicle will charge it, but according to the logic set by different manufacturers, some new energy vehicles will actually be unable to open the door lock because the 12V battery is out of power, which we have encountered.
3, like car anti-theft system, door locks these low-load electrical assembly, do not need to use 200V-400V power battery high voltage, so the new energy vehicle will let the high voltage "power down" during the shutdown to save power loss, only use 12V for vehicle monitoring.
4. Like 48V light hybrid vehicles, the 12V lead-acid battery of new energy vehicles is still a consumable.
Is there a future for the ancient lead-acid battery?
1, there have been racing vehicles using 12V lithium batteries to replace heavy lead-acid batteries, and now there are also civilian vehicles began to use lithium batteries instead, such as BYD DM-i hybrid uses its own 12V lithium iron phosphate battery, weighing only 2.2±0.2kg.
2, the traditional 12V lead-acid battery industry chain is very complete, cost-effective, even if the vehicle is gradually decommissioned, it can also continue to be used on non-mobile platforms, and its industrial scale is in a period of decline.
3, lead-acid battery weight reduction task is extremely difficult to achieve, the technology tree energy point skills have been full, the next thing to do is to use lithium-ion batteries to replace lead-acid.
4, the advantage of lead-acid formula is that the thermal runaway has been changed to a very low, and very few vehicles are spontaneously combusted because the lead-acid battery is thermally out of control. In addition, the operating temperature of lead-acid batteries is as wide as -20 °C -60 °C, which is unmatched by the vast majority of current lithium batteries.