As we all know, the voltage platform of the traditional lead-acid battery is 12V, the discharge rate is only about 3-5C, and the discharge curve is a straight downward slope. If your car’s lead-acid battery has been used for a long time or the battery quality is not very good, or if it is not for a long time Turning on causes the battery to lose power. When the voltage is relatively low, such as below 12V, the battery voltage will be pulled too low when the car is started (may be lower than 7V), the car can be started, but it will be more difficult to start, and I feel that the power is insufficient, Due to the battery undercharge, the engine will be restrained when charging, the ECU will think that the battery is always not fully charged and continue to charge, continue to convert the power into electrical energy, and the internal resistance of the battery will gradually increase. This part of the electric energy will be consumed, and electricity will be wasted, which indirectly affects the fuel consumption and increases the fuel consumption of the car. The battery voltage is low, which will affect the work of the ignition coil of the car. (The high voltage package, also called the ignition coil, is to transform the normal 12V voltage into a high voltage of ten thousand volts, and then the ignition in the cylinder is used to ignite The high-pressure combustible gas in the cylinder starts the engine to work and generate power. When the high pressure package generates high pressure, it is about 15000V-30000V (different models vary). The high pressure obtained may be low, which may cause insufficient ignition temperature and affect fuel. There is a probability of incomplete combustion, which indirectly affects the fuel consumption and power of the car, and the car may also be idling unstable and jitter.
On the other hand, lowering the battery voltage will result in insufficient fuel pump and cylinder pressure, resulting in poor fuel atomization from the fuel injectors, inadequate fuel combustion and increased fuel consumption. Many electrical circuits in automobiles use 12V as the standard operating voltage platform. Especially for some sensors, when the voltage is lower than 12V or is unstable, the related circuits will also be unstable.
The new energy lithium battery material used in the lithium battery has a built-in smart BMS (battery management system circuit), which can protect against overcharge, overdischarge, and even short circuit protection. Take the lithium iron phosphate battery as an example. Its cell voltage is 3.2V, while the unipolar voltage of a lead-acid battery is only 2V. A battery composed of lithium iron phosphate batteries has a high voltage platform, which can reach more than 13V. Within a reasonable vehicle voltage range, and the discharge voltage platform of the lithium battery is very stable, and can be charged and discharged at a high rate, and some can reach more than 30C. Therefore, when using a lithium iron phosphate battery as a starting battery, the battery voltage will not be as low as the car starts. It is pulled too low and can be kept above 11V (lead-acid may be reduced to below 7V), so that the car ignition system maintains a higher and more stable voltage, so that the ignition system of the spark plug is in the best state, and the ignition will cause fuel mist instantly Qualified chemical, full combustion, full heat, reduced loss, and reduced emissions. The stable voltage of the car engine when running at high speed can ensure the pressure balance in each cylinder, and the fuel is fully burned. While refueling and speeding up, the engine is strong and powerful. In addition, the high-rate charge and discharge characteristics of the lithium iron phosphate battery also make the battery It is fully charged quickly, achieving high-efficiency power conversion, and the battery charging speed is fast, which reduces the engine load. Experiments have proved that stable voltage can also significantly improve air conditioning and lighting, and improve the output power and tone of car audio. There is also an intuitive reason. The weight of lithium batteries is less than 10KG, and the lead-acid batteries are more than tens of kilograms. The direct weight reduction can also save some fuel consumption.
Tested by a variety of cars (Excellence 1.6L, Mercedes-Benz E260/2.0T, Cayenne 4.ST, BMW 740, Camry 2.5L, Audi A6/2.0T, Volkswagen Lavida 1.6L, Geely Emgrand, Chery Land Rover, etc.) test shows that the average fuel saving At about 10%, the parameters are different for different models, vehicle conditions, road conditions, and driving habits.
