At present, there are more and more electric vehicles, and most of my friends like them. Electric vehicles also have many advantages, such as subsidies and reduced air and gas pollution. The most important thing is that electric vehicles save fuel. But friends should think that the most important thing about electric cars is the battery. So friends, do you know about the batteries in electric cars? Today, the editor will briefly introduce the lead-acid battery of electric vehicles to friends.
Lead-acid batteries for electric vehicles: Lead-acid batteries
Definition: The electrodes are made of lead and its oxides, and the electrolyte is a battery containing a sulfuric acid solution. Chinese: Lead-acid battery. In the discharge state, the main component of the positive electrode includes lead dioxide, and the main component of the negative electrode includes lead; in the charged state, the main component of the positive and negative electrodes is lead sulfate. Includes vented batteries and maintenance-free lead-acid batteries.
The battery key consists of a tubular positive plate, a negative plate, electrolyte, separator, battery tank, battery cover, electrode, liquid injection cover, etc. The electrodes of the exhaust battery are composed of lead and lead oxide, and the electrolyte is a sulfuric acid aqueous solution. The key advantages are stable voltage and low price; the disadvantages are low specific energy (that is, the amount of electrical energy stored per kilogram of battery), short service life, and frequent maintenance. Most old-fashioned batteries have a service life of about 2 years, and they need to regularly maintain the electrolyte level and add distilled water. However, with the development of science and technology, the life of lead-acid batteries is getting longer and longer, and maintenance is becoming easier and easier.
The most obvious feature of lead-acid batteries is that they have a plastic sealing cover that can be unscrewed at the top, and there is a ventilation hole on it. These liquid-filled caps are used for filling pure water, detecting electrolyte, and venting. According to theory, the density and level of the electrolyte should be checked every time a lead-acid battery is maintained, and distilled water should be added if it is missing. However, with the upgrade of battery manufacturing technology, lead-acid batteries have developed into lead-acid maintenance-free batteries and gel maintenance-free batteries, which do not require the addition of electrolyte or distilled water to lead-acid batteries. The key is that oxygen can be absorbed into the oxygen circulation of the negative electrode through the positive electrode, which can avoid moisture shortening. Lead-acid batteries are mostly used in tractors, tricycles, car starters, etc. , while maintenance-free lead-acid batteries are widely used, including uninterruptible power supplies, electric vehicle power supplies, electric self-driving batteries, etc. Lead-acid batteries include constant current discharge (such as uninterruptible power supplies) and transient discharge (such as car starter batteries) depending on the application.
Lead-acid batteries for electric vehicles: How to use
(1) Do not short-circuit the battery. When the positive and negative terminals of the battery are electrically contacted by external substances, the battery will short-circuit. For example, a battery without outer packaging placed in a pocket may short-circuit due to contact with metal materials such as keys or coins.
(2) Install the battery so that the polarity markings of the battery ("+" and "other-") correspond well with the markings of the electrical appliance. If the battery is improperly installed in an electrical appliance in the opposite direction, short circuit or charging may occur, affecting the rapid rise in battery temperature.
(3) Do not try to charge the battery. Charging a non-rechargeable primary battery produces gas and heat inside the battery.
(4) There is no need to force the battery to discharge. When a battery is forced to discharge, its voltage will be lower than its design performance and gas will be produced inside the battery.
(5) No need to heat or directly weld the battery. When a battery is heated or welded, the heat can cause an internal short circuit within the battery.
(6) Do not disassemble the battery. When disassembling or separating the battery, there may be contact between battery components, which may cause a short circuit.
(7) There is no need to mix old and new batteries or batteries of different models and brands. When replacing batteries, all batteries should be replaced with new batteries of the same brand, model and batch at the same time. When batteries of different brands and models or old and new batteries are used together, some batteries will be over-discharged due to differences in voltage or capacity between different batteries.
(8) There is no need to deform the battery. No crushing, puncture or other form of battery damage is required. These abuses often affect the battery by short circuiting.
(9) Do not put batteries into fire. When a battery is placed in a fire, the accumulation of heat can affect explosions and personal injury, so there is no need to use all means to burn the battery other than proper and adjustable incineration.
(10) Do not let children touch the battery or replace the battery without adult supervision. Some batteries that can be swallowed should be kept away from children as much as possible, especially some batteries that can be placed in the feeding device as shown in the picture. Once someone has eaten a battery, he should seek medical help immediately.
(11) No need to seal or replace batteries. Sealing the battery or replacing the battery in other ways will block the battery's safety valve, making it impossible to discharge immediately when gas is generated inside the battery. If it is deemed necessary to replace the battery, this should be advocated by the manufacturer whenever possible.
(12) For unused batteries, please keep them in their original packaging and keep them as far away from metal substances as possible. If the packages have been opened, they should be discharged in an orderly manner and should not be piled up randomly. When unpackaged batteries and metallic materials are mixed together, the battery may short circuit. The best way to prevent this from happening is to store unused batteries in their original packaging.
(13) Unless used in emergencies, batteries that have not been used for a long time should be removed from electrical equipment as much as possible. When a battery fails to perform satisfactorily or when it is not expected to be used for an extended period of time, it is beneficial to remove it from the device. Although batteries on the market are basically equipped with protective cases or use other methods to regulate leakage, some or all used batteries are still more likely to leak than unused batteries.
Lead-acid batteries for electric vehicles: What should we pay attention to?
Use environment and safety
1. Lead-acid batteries are naturally well ventilated and the optimal ambient temperature is a workplace of 25±10℃.
2. Lead-acid batteries will be very safe under these conditions: good conductive connections, no serious overcharging, no direct radiation from heat sources, and natural ventilation.
What should I pay attention to during the installation process?
1. The battery should be kept away from heat sources and places prone to sparks, and its safety distance should be greater than 0.5m.
2. The battery should be kept away from direct sunlight and should not be placed in an environment with a large amount of radioactivity, infrared radiation, ultraviolet radiation, organic solvent gases and corrosive gases.
3. The installation ground should have sufficient bearing capacity.
4. Due to the high voltage of battery components, there is a risk of electric shock. Therefore, insulating tools should be used when loading and unloading conductive connecting strips, and insulating gloves, aprons, and protective glasses should be worn when installing or handling batteries. During battery installation and transportation, only non-metallic slings can be used, and steel wire ropes cannot be used. 5. Dirty connecting strips or loose connections may cause the battery to catch fire or even damage the battery pack. Therefore, when installing, please carefully check and remove the dirt on the connecting strip, and then tighten the connecting strip.
6. Batteries with different capacities and performances cannot be used interconnected. Before installing the terminal connectors and connecting the battery system, the total voltage and positive and negative electrodes of the battery system should be carefully tested to ensure a good installation.
⒎The battery casing should not be cleaned with organic solvents, nor should dry powder fire extinguishers be used. It is recommended to use a carbon dioxide fire extinguisher to extinguish battery fires.
8. When the battery is connected to the charger or load, the circuit switch should be in the "disconnect" position and ensure a good connection: the positive pole of the battery is connected to the positive pole of the charger, and the negative pole is connected to the negative pole.
Transportation and Storage
1. Because some batteries are heavy, we must pay attention to the use of transportation tools. It is strictly forbidden to throw away the battery pack in its packaging box.
2. When transporting batteries, do not touch the poles and safety valves.
3. The battery is filled with liquid, and short circuit of the battery should be avoided during transportation.
4. The battery can be stored at 0~35℃ before installation, but the storage period should not exceed 6 months. Batteries with a storage period of more than 6 months should be charged and maintained, and the storage place should be clean, ventilated, and dry.
What to use and pay attention to?
1. When the battery is charged at the factory, the battery capacity will suffer varying degrees of loss from leaving the factory to installation and use. If it takes a long time, it should be charged before putting it into use. If the battery's storage period is less than 1 year, charge it for 5 days at a constant voltage of 2.27 volts/battery. If the battery's storage period is 1 to 2 years, charge it for 5 days at a constant voltage of 2.33 volts/battery.
2. When the battery is used for float charging, the float charge voltage of each single cell should be 2.25~2.30V. If the float charge voltage is higher or lower than this range, the battery capacity or service life will be reduced. will be shortened.
3. When the battery is floating, the battery cell voltage should not be lower than 2.20 volts. If the battery cell voltage is lower than 2.20 volts, balanced charging is required. The balanced charging method is: charging voltage 2.35 volts/piece, charging time 12 hours.
4. When recycling the battery, use constant voltage and current limiting charging after discharge. The charging voltage is 2.35~2.45V/unit, and the maximum current does not exceed 0.25C10. The specific charging method is: first charge with a current not exceeding the maximum current. When the average voltage of the standby unit rises to 2.35~2.45V, then charge with 2.35~2.45V constant voltage charging until the end of charging.
⒌Signs of full charge during battery recycling:
When the charge is good under the above-mentioned current limiting and constant voltage conditions, the battery capacity can be judged by either of the following two items Adequate signs:
(1) Charging time is 18~24 hours (non-deep discharge time can be shorter).
At the end of charging,?The charging current value remains unchanged for three consecutive hours.
⑶The voltage value for constant voltage 2.35~2.45V charging is the specified value at an ambient temperature of 25°C. When the ambient temperature is higher than 25°C, the charging voltage needs to be reduced accordingly to avoid overcharging. When the ambient temperature is lower than 25°C, the charging voltage should be increased to avoid insufficient charging. Generally speaking, the increase or decrease range of each monomer is 0.005 volts for every 1°C change.
6. The battery should be charged immediately after being discharged. If a discharged battery is left alone for too long, it may not regain its original capacity even with further charging.
⒎When using the battery, be sure to tighten the terminal bolts to avoid sparks and poor contact.
Battery operation detection and recording
1. After the battery is put into operation, the float charge voltage and open circuit voltage should be measured at least once every quarter, and the float charge voltage of each single cell should be recorded. Or open circuit voltage value;
2. Terminal voltage (total voltage) of the battery system;
3. Ambient temperature.
3. The connecting wires should be inspected for lifting and corrosion contamination every year. Suspended wires must be tightened immediately, and corrosion-contaminated joints must be cleaned immediately.
⒌During operation, if the following abnormalities are found, immediately find out the cause of the fault and replace the faulty battery:
The voltage is abnormal;
⒎Physical damage ( The casing and cover are cracked or deformed);
Leakage of battery fluid;
Abnormal temperature.
After reading the introduction of the car series, do you need to know more about lead-acid batteries for electric vehicles? So, do your friends like what Bianxiao Auto has briefly introduced to your friends today? Auto Editor believes that it is very necessary for friends to understand electric vehicles. Because electric vehicles will definitely be widely used in the future, I hope the auto editor’s introduction can solve problems for friends.
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