What is the voltage and current of the electric car battery?

One of the important performance indicators of battery performance is the battery capacity, which indicates the amount of electricity discharged by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.) (Discharge test can be performed with JS-150D), that is, the capacity of the battery, usually in amps. The hour is the unit (abbreviated as AH, 1A.h=3600C). The calculation formula of the battery capacity C is C=∫t0It1dt (integration of current I during t0 to t1). The battery capacity is divided into actual capacity according to different conditions, theoretical capacity and rated capacity. The minimum capacity to be discharged at a certain discharge rate at 25 ° C to the termination voltage is the capacity of the specified battery at the time of design and production. This is called the rated capacity of a certain discharge rate RH. The battery capacity is generally calculated in AH (ampere-hours), and the other is calculated in CELL (unit plate) several watts (W). (W/CELL) 1. AH (ampere hour) calculation, discharge battery (constant current) I × discharge time (hour) T. For example, if the 7AH battery has a continuous discharge current of 0.35A, the time can be continuous for 20 hours. 2. The charging time is based on 10 hours, and the charging current is 1/10 of the battery capacity. Fast charging will reduce battery life. Battery capacity refers to the amount of battery storage. The unit of battery capacity is “mAh”, and the Chinese name is mAh (when measuring large-capacity batteries such as lead storage batteries, for the sake of convenience, it is generally indicated by “Ah”, the Chinese name is Anshi, 1Ah=1000mAh). If the rated capacity of the battery is 1300mAh, if the battery is discharged with 0.1C (C is the battery capacity), that is, 130mA, then the battery can work for 10 hours (1300mAh/130mA=10h); if the discharge current is 1300mA, then the power supply The time is only about 1 hour (the actual working time varies depending on the individual differences in the actual capacity of the battery). This is an analysis under ideal conditions. The current of a digital device in actual operation cannot always be constant at a certain value. (In the case of a digital camera, the operating current will be large due to the opening or closing of components such as the LCD display and flash. Change), so the battery can only provide a certain value for the power supply time of a device, and this value can only be estimated through practical experience.

Day cannot forget the pain

From the knowledge of partner certification experts recommended on 2017-09-16

The capacity of the mobile phone battery depends on two points:

1. The capacity of the battery is affected by the size of the mobile phone battery and the current manufacturing technology. The battery capacity of 1200MA is considered to be ultra-high capacity. If the battery exceeds 1200MA, except for the large battery and the other batteries will be somewhat virtual. The size of the battery shell determines the maximum capacity of the battery, that is, how large the battery shell is and how much the battery can do.

2. The quality of the battery determines the quality of the battery: careful consumers press the battery with their fingers it will find that some places are empty, which means that the battery is small, plus the battery itself is poor, plus small size Actual capacity is often small. There are many domestic mobile phone batteries and unbranded mobile phone batteries on the market that are virtual standard products. The actual product capacity is less than 400-500MA, but it is marked with thousands or even higher capacity, so remind consumers to buy batteries. First, we must choose a regular brand, a regular manufacturer, and then choose the capacity.

The capacity of a battery depends not only on its size but also on its energy density.

Energy density × volume = energy

Generally, the energy density of a lithium ion battery > nickel hydrogen battery > nickel cadmium battery > zinc carbon battery

The energy here, the battery is often marked XXmAH, meaning that the current is discharged for 1 hour the energy stored in the battery is all converted into electrical energy (rated energy, in fact, some energy remains).

For example, if the battery is 1200mAH, if it is used on the radio and the working current is 50mA, the radio can work:

1200/50=24 hours

In actual use, our radio has a smaller current and is used intermittently, so the battery life will be longer.

3 The device that converts chemical energy into electrical energy, no matter how large the size is, a single dry battery is 1, and it can also convert chemical energy into electrical energy.

2 The voltage of the battery is determined by the power of each primary battery.

It is common that the dry battery is 1 each. The size of the battery depends on the chemical nature of the internal material.

The reaction of the discharge is complete

Must be charged to cause a reverse reaction to charge

The reaction of this discharge can be carried out again.

1 The battery's power is generated by the chemical reaction of its internal chemicals, so it can be charged and discharged. Usually, the dry battery has less chemical energy, so the power is less. But the battery may convert electrical energy into chemical energy at the time. 5V is determined by its chemical properties.

The voltage and current output of the electric vehicle battery determines the driving power of the electric vehicle. The voltage and current output are high, the power is strong, and the speed can reach the highest value. When the electric vehicle runs at a constant speed, the voltage and current will remain relatively constant. The power is output.

The electric vehicle is controlled by the controller to control the power output. The controller issues the command output power from the battery pack according to the power required during the operation of the electric vehicle. The power = voltage * current. At constant power, the higher the voltage, the current. The smaller, the constant power output is usually at the constant speed of the electric vehicle, so the power consumption is the most economical at this time (small current discharge, voltage drop is slow). When starting or climbing the motor power demand increases, the battery will become lower and lower with the extension of the running time, the current will become larger and larger, especially when the power consumption is above 50%, it will be very It is difficult, because when the current is increased, the battery voltage drops and the controller voltage is dropped, and there is no power supply.

The starting current, the creeping current, and the current of the electric vehicle are 1.2 to 1.5 C when the vehicle is riding at a constant speed. C is the battery's 2 hour rate capacity. For example, if the battery capacity is 20 AH, the current is 25 A to 30 A. Large current discharge will cause certain damage to the battery, and will shorten the discharge time. If the switch is slowly turned on at the start, the power will increase slowly, which will greatly reduce the damage to the battery and prolong the discharge time, thus extending the mileage.

The methods for extending the mileage of electric vehicles are as follows:

1. Start slowly, reduce the acceleration process, and try to drive at a constant speed. On the one hand it can extend the battery life. On the other hand, it is also beneficial to battery life.

2. Improve the configuration of electric vehicles and increase battery capacity. If you want to have good endurance, you can install a large capacity battery as much as possible under the premise of installation space, which can extend the renewal time.

The page contains the contents of the machine translation.