In May 19th, a complaint in the car quality network car complaint column was found in a complaint column of the car quality network. The complaint was that after the new car was bought from 5% to 100%, it could only be charged 9 degrees, driving 30 kilometers, and the nominal and advertising was 13 degrees.



The data shows that BYD Qin is a high-performance three box car of the Byd Company Limited (hereinafter referred to as BYD) the two generation of independent research and development of the DM (switching between two modes of pure electric and hybrid power).

In addition, BYD Qin's complaint shows that from June 24, 2014 to June 9, 2015, there were 25 complaints about BYD Qin, of which 10 complained about the failure of the battery, mainly in the purchase of the BYD Qin's mileage far from the factory publicity standards and the lack of car charging. The problem.



"It is not only BYD Qin, but now the electric motor, control system and battery in three parts of the market, the battery is still the biggest problem that restricts the development of electric vehicles. Whether it is to choose the batteries such as lithium phosphate lithium battery or graphene, which is good to choose, now there is no definite answer. Wang Gai, a car commentator, pointed out to the weekend of the rule of law.



"At present, why do so many people dare not buy electric cars because they are worried about the battery?" The auto industry insiders said in an interview with the rule of law Weekend reporter.



The speed of listing may be too fast



Data show that BYD Qin used the lithium phosphate lithium power battery charging amount of 13kW. H, mixed mode system 90% using pure mode, its comprehensive driving range of 70 kilometers.



"BYD Qin" mainly uses the BYD lithium iron phosphate battery, adding some cobalt elements into the battery, which enhances the cycle efficiency of the whole battery. So, many people call the iron phosphate cobalt lithium battery. " Industry insiders say to the rule of law weekend reporters.



People in the industry on the rule of law weekend reporters pointed out that in fact, the principle of Qin's work is very simple, a double clutch DCT gearbox, an inverter, an external power plug, an inverter, which constitutes the power system.



"There is no clear definition of the battery capacity of Qin. However, according to the price, it should be 60AH's monomer. Whether charging or discharging, the low voltage of a single battery will seriously affect the cycle life of the whole battery pack, which is beyond doubt. Industry insiders say to the rule of law weekend reporters.



Car commentator ho Lun told the rule of law weekend reporters that in fact, BYD Qin should not have such a situation, now BYD and Benz cooperation, should learn a lot of research and development, put into production standards and so on. They did well in accordance with Mercedes Benz's standards in developing and developing Teng motors.



"There is still a problem with how to bring the related content of research and development to BYD. BYD should calm down, do not rush to launch a new car, do some of the original things, or lose more things. " Ho Lun told the rule of law weekend reporters.



Industry insiders told the weekend of the rule of law that at present, the market timing of BYD Qin's electric vehicles may be too fast.



Data from the China Auto Industry Association (China Auto Industry Association) shows that BYD has a market share of 27.9% in the field of domestic new energy vehicles and 49.6% (2014) in the plug - in hybrid market. First electric network data show that in the first quarter of this year, BYD's share in the global automotive battery market also increased from 6% in the previous year to 9%.



Therefore, there is a view that BYD Qin is subject to the quality of the power battery of the owners, because BYD, in order to be able to catch the country's subsidy to new energy as soon as possible, has rushed to the market to launch a plug in car Qin.



According to the 2010 Ministry of Finance and other 4 ministries and commissions issued by the Ministry of Finance and other ministries and commissions of the "private purchase of new energy vehicle subsidy pilot", the subsidized plug - in car must have a 50 km range of conditions (pure electric model).



Battery management system is tested

Many people in the industry have pointed out to the rule of law weekend reporters that, in fact, it is not only the problem of BYD Qin's power battery, which is very common in the entire electric car industry.



He explained to the rule of law weekend reporters that the current limiting factor for electric vehicle endurance is the energy density of the battery, so there is a need for a battery technology with a larger energy density but smaller weight. But at this stage, if we want to enhance the power of cars, we need to increase the number of batteries, which will increase the weight.



"The problem of energy density is a catch up situation in the industry. Both are increasing the energy density of the unit weight, and the energy density determines the mileage of the mileage." He told the rule of law weekend reporters.



In addition, industry insiders explain to the rule of law weekend reporters that, according to regular lithium battery production, most enterprises, in order to ensure their endurance, say that the battery capacity is 10AH. However, they usually install more 0.5-1AH, so that even if the capacity is reduced, they can still meet the demand.



"BYD as a power battery company, their battery quality is definitely no problem, this is their core competitiveness." Industry insiders pointed out to the rule of law weekend reporters.



But the car commentator bell division told the rule of law weekend reporters that the car owners failed to reach the manufacturer's standard when charging the battery, because the battery had a decay process. The decay of batteries used in electric vehicles is inevitable, which is the natural attribute of batteries.



"How much distance can be run after the first electric car can run, with the passing of time, the appearance of the surface is full, but the electricity can not go in slowly, the phenomenon of aging, and eventually the endurance of the endurance is also attenuated." The bell teacher explained to the rule of law weekend reporters.



Secondly, the industry people on the rule of law weekend reporters explained that although the BYD battery has no problem, but the BYD battery group technology, and can not be said to be the world's first class. Battery to battery group must have battery management system (BMS) intervention. A battery pack is like a power battery pack, good match, good effect, bad match, and bad effect.



In this regard, he Lun told the Weekend reporter of the rule of law, the battery management system determines the reliability and consistency of the performance of electric vehicles. Because once the battery management system itself problems, resulting in some batteries are not good, it will affect the overall battery effect.



The reliability of EV design depends on its reliability. If the battery is used in series, a battery is in problem, the whole problem will appear, so the production process will involve the problem of consistency production. He told the rule of law weekend reporters.



Control battery attenuation to key



The characteristics of the lithium iron phosphate battery itself determine that the battery is definitely decaying, and domestic enterprises are very clear about this fact. Industry insiders told the weekend of the rule of law, "therefore, it is very important to maintain the use process, especially avoid overcharging and overdischarging."



People in the industry suggested to the rule of law Weekend reporter that the solution to this problem is relatively simple. In fact, the domestic plug-in hybrid electric bus solves this problem very well.



And he believes that many companies are trying to solve the problem of electric vehicle batteries, they can choose to learn from Toyota Auto Body Co (hereinafter referred to as TOYOTA). "They use super capacitor instead of a part of the battery, fully play the characteristics of the super capacitor can quickly charge and discharge, while the introduction of the battery to play the capacity of the battery storage capacity characteristics, when the brake and start, with super capacitor output, long distance pure electricity driving, the battery plays a role." Industry insiders pointed out to the rule of law weekend reporters.



"In fact, TOYOTA has also appeared in the beginning of the battery attenuation situation, and to take free to provide customers with the battery replacement service, to pay a great price." He pointed out to the rule of law weekend reporters.



He told the rule of law weekend reporters that now TOYOTA hybrid battery, the battery start to decay time nodes can now exceed the warranty period, more than the quality of the warranty, the battery has hardly been the problem of attenuation. At present, the warranty period of TOYOTA is 100 thousand kilometers, and the level of battery attenuation can be controlled within 8% when it reaches 4. 5 million kilometers. This is a very unbelievable data.



He Lun to the rule of law Weekend reporter pointed out that the industry believes that the attenuation of rechargeable batteries is almost inevitable. However, because TOYOTA requires that the battery will not store less than 25% of the total storage capacity, it will begin to store electricity at the level of one to 25%, which is the lower limit. The upper limit is no more than 75%, and the upper limit is 25%. "