Precautions for use (discharge):
For batteries, normal use involves the discharge process. There are several points to note when discharging lithium-ion batteries:
First, the discharge current should not be too high. Excessive current will cause the battery to overheat, potentially leading to permanent damage. This is not a problem for mobile phones and can be disregarded.
The higher the battery discharge current, the smaller the discharge capacity and the faster the voltage drops.
Secondly, never over-discharge! Lithium-ion batteries store energy through a reversible electrochemical change. Excessive discharge can cause irreversible reactions in this process. Therefore, lithium-ion batteries are extremely vulnerable to over-discharge; if the discharge voltage drops below 2.7V, the battery may be rendered unusable. Fortunately, mobile phone batteries have built-in protection circuits. Before the voltage drops to a level that could damage the battery, the protection circuits activate and stop the discharge. The difference between fast and slow charging for lithium-ion batteries...
1. Given the current level of electric vehicle power lithium battery technology, the best driving habit is to use slow charging more and fast charging less. Although slow charging is less efficient in terms of time, it does not harm the health of the power lithium battery and can charge the lithium-ion battery more fully.
2. The charging speed of electric vehicles is closely related to the charger's power, battery charging characteristics, and temperature. With current battery technology, fast charging takes about 30 minutes to reach 80% of the battery's capacity. Beyond 80%, to protect the lithium-ion battery, the charging current must decrease, making it take longer to charge to 100%. Furthermore, in cold winter temperatures, the battery requires a lower charging current, further extending the charging time.
3. A car has two charging ports because there are two charging modes: constant voltage and constant current. Generally, constant current is used first, followed by constant voltage, for higher charging efficiency. Fast charging is faster because of the difference between charging voltage and current; the higher the current, the faster the charging. When the battery is almost fully charged, constant voltage is used to prevent overcharging and protect the battery.
4. Slow charging uses relatively low charging current and power, which is better for the lifespan of lithium-ion batteries and reduces charging costs during off-peak hours. Fast charging uses higher current and power, which can significantly impact the battery pack and its lifespan. Fast charging also requires additional equipment, such as AC/DC converters, which increases costs.
The more a battery is fast-charged, the shorter its cycle life. Manufacturers generally recommend that consumers reduce the number of times they use fast charging and use slow charging with normal voltage more often to extend the battery's lifespan as much as possible.
The charging speed of lithium-ion batteries in new energy vehicles depends on three key factors: battery density, temperature, and materials. In other words, if any one of these factors is substandard, fast charging can severely damage the battery. Furthermore, the battery management system (BMS) is also crucial; it controls the input current and voltage during charging to minimize potential damage to the battery.
Modern new energy vehicles can be charged using either slow or fast charging. Slow charging typically takes 8-10 hours, while fast charging is much faster than lithium-ion batteries. Currently, a full charge of a new energy vehicle with fast charging takes about an hour. However, fast charging can have some impact on battery lifespan. If you're not in a hurry, regular charging is sufficient.
