The factors affecting the service life of electric vehicle battery

Electric vehicles in use process, belong to the consumable, battery is directly related to the use of user fees, the normal use of storage battery charging and discharging cycle can reach more than 500 times, and is often found in the process of actual use of battery life is much lower than the charge-discharge cycles, according to the analysis of the main reasons are as follows: 1, the deficiency of electric vehicle battery often by 2 ( 24V） Or three ( 36 v) Individual battery series battery, so to form the individual battery of battery need to make the necessary testing, to pick each battery of individual characteristics consistent battery to achieve the best combination effect, thus improve the life of the battery. Otherwise, the use of the individual characteristic differences of individual battery of battery will affect battery life. One of the smaller individual capacity, for example, is the individual first charged at the time of charging and enter the charging status, and in the discharge when the individual first after electricity and into the discharge ( Is equivalent to using a dry cell, old and new batteries mixing effect) Further reduced, which makes the individual capacity, into a vicious circle. Now some manufacturers have no corresponding testing equipment, not necessary matching tests, make use of battery has the congenital deficiency, affect the service life of the electric car battery. 2, a battery charger factors work cycle for charging and discharging process, so it is also an important factor affecting the service life of battery charging process. Recharging the battery charging current size, control mode and so on directly affect the service life of battery. Battery capacity and voltage determines the parameters of the charge, so, the parameters of the charger should match the parameters of the battery, charging to reduce improper damage to the battery. In pursuit of quick charge current, some charger will be charging current is added to ( 0. 3 - 0. 5) Times C ( C - - Battery capacity value) , and use some special way of charging control, in order to reduce the charging time, of course, there is indeed a lot of this charger to achieve this purpose, but it also increases the chances of damage to the battery. For example, a well-known brands of domestic electric cars, negative pulse charger to choose more advanced depolarization charger, but combined with the battery pack is undeserved, it caused the damage to the battery, the charger has the advantages of the damaged battery instead of faults, seriously affect the service life of the battery. So choose reasonable charging parameters of charger and battery matching parameters, can make the electric car battery life extension. 3, controller factors work cycle of battery discharge process is the electric drive, and controller controls the various parameters used in the process of driving, control the discharge of battery parameters, so the controller is also one of the important factors affecting the service life of battery. Curiously now people tend to ignore this factor, and will affect battery life problem to battery manufacturer and charger, can sometimes make the battery manufacturer and charger wronged. Battery discharge during the process of the main damage factors are two: ( 1) Large current discharge. The maximum 12 ah lead-acid battery discharge current for C, followed by 12 a, and gel battery electric vehicle chooses, so less maximum discharge current. And at present the electric car manufacturers in order to improve the acceleration and gradeability and load level, often make the controller of the current limiting current extended to more than 14 a ( Even more than 20 a) , the performance is improved, but the harm of storage battery are real, of course, these problems at the beginning of the user is unaware of, often in use after a period of time to reflect. Because, when the users use, each acceleration, every grade is damage to the battery. A solution to this problem can only be used with double closed-loop control of the controller. （ 2) After discharge. Discharge is also an important factor of damage to the battery, so the controller generally have under-voltage protection circuit, but to prevent the use of recovery voltage of battery, The battery to stop after discharge, battery voltage will pick up 2 - 3 v) , should choose under-voltage protection circuit with voltage hysteresis control, so as to do to ensure that the battery will not discharge.