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Electric car charger brief description

Release time:

2024-06-27

The controller and charger are critical to the life of the vehicle battery. The controller should prevent overdischarge while taking electrical energy from the battery; the charger should prevent overcharge while charging the battery.

1. Overview

(I) charger and vehicle battery

The controller and charger are critical to the life of the vehicle battery. The controller should prevent overdischarge while taking electrical energy from the battery; the charger should prevent overcharge while charging the battery. Otherwise, the battery plate is damaged either because of overcharge or overdischarge, and the battery life will soon end. Therefore, the charger and controller are like the guardian of the battery, protecting it in the process of charging and discharging. Similarly, undercharging still does not work. The result of undercharge is that the active material becomes stubborn and is no longer prone to reduction reaction and passivation. This part of the polar plate only occupies space and weight and no longer stores energy. The more ineffective substances in this part, the lower the battery capacity. Over-charge, over-discharge, and under-discharge are the three major factors that endanger battery life.

(II) pulse charging

Pulse charging is a discontinuous, fixed voltage square wave to charge the battery, the charging current is larger. At the initial stage of charging, the positive and negative plates are both in the lead sulfate state, which has a greater acceptance capacity. At the same time, due to the discontinuity of square waves, there is a stop interval between each waveform, which gives the active material of the plate a sufficient opportunity to react, adjust and balance the internal and external substances, so the initial charging is faster. As the material of the plate is continuously reduced, the voltage is continuously increased, the charging speed is continuously slowed down, the reaction speed of the active material is gradually reduced, and a large number of charged ions are gradually accumulated around the plate, surrounding the plate, isolating the plate and preventing the subsequent charged ions from reaching the active material. When the plate potential reaches the limit (near the end-of-charge voltage), the electrochemical action almost stops. To the polarization point, the water around the plate is decomposed, which is characterized by a large amount of bubbling and water evaporation. A large amount of oxygen is adsorbed on the surface of the positive electrode and a large amount of hydrogen is adsorbed on the surface of the negative electrode. The voltage at this time is called the "gas production point".

To solve and eliminate this polarization phenomenon that hinders charging, the method is to stop charging briefly, and then use a large, reverse direction, and extremely short time current-negative pulse to apply a reverse voltage to the positive and negative plates to clear a large number of positive and negative ions and gases gathered around the plates to clear the way. The back pulse is actually a discharge measure. The method of short-circuiting the positive and negative poles can also eliminate the polarization, or the polarization phenomenon can be eliminated by itself, but the negative pulse is more powerful, faster and more time-saving.

(III) switch circuit charger

The current electric vehicle charger is completely different from the traditional charger in the past. The charger uses a switch circuit and is equipped with automatic adjustment, control and protection functions. During charging, no one is required to guard it. The advantages of the switch circuit are fast charging, good quality, high efficiency, and no loss of battery life.

Switching circuit is the current commonly used to stabilize the current, automatic adjustment device, and the use of pulse device circuit. Charger circuit and controller circuit and home audio, color TV, etc. belong to the same type. As long as a little modification, increase or decrease some components, can almost substitute.

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