Battery Technical Info

Does frequent fast-charging harm electric vehicle battery?

Ebike Battery

Under a variety of eyes and a variety of voices, new energy vehicles all the way ups and downs came to us. Although the initial road is difficult to move on, the new energy this snowball is rolling bigger and bigger, especially in the period of Covid-19 spread, more and more people are in high demands of Ebike, E-scooter, and electric four-wheeler vehicle. They are not only successfully entered the common people’s home, but also lead people to pay high attention to the Ebike lithium battery, Escooter Lithium battery and, 4-wheeler lithium battery.

For Consumers, when buying a new energy vehicle, such as Ebike, the topic of greatest concern is its range. Today, with the continuous upgrading of technology, the range of electric vehicles has increased correspondingly. Especially this year, the range of electric vehicles has reached the level of 400-500 km, and the range of electric bicycles has reached 80-120 km, which takes all the anxiety out of the endurance. Except for Range, another major factor that impacts customer purchase is charging speed.

Electric Vehicle Battery charging

Usually, vehicles will mark “slow charge time” and “fast charge time”, in which the fast charge time is the biggest competition point among major car companies, who fast charge time is shorter who sell better, the attention will be higher. In press releases, we can often see such phrases as: “The electric car has been called the Vivo of the automotive world. Charging for five minutes lasts for two hours, and from then on, the trouble of long charging is over. ” A Cup of coffee takes 80 percent time to charge, who’s to say electric cars don’t work.

So we can see, whose quick charge time is shorter, have gimmick more in front of the consumer. If the fast charge is so powerful, why is there a slow charge? As the saying goes: Haste makes waste. In fact, in the field of pure electric vehicles is the same principle, although fast charging can shorten the charging time, but also the greater harm to the battery. Isn’t it a bit surprising that a quick charge would harm the battery? Today, SmartPropel will together with you to talk about that.

First of all, before we solve this problem, let’s understand the difference between slow charging and fast charging. As we all know, the slow charge is AC, the charge time is usually 5-8 hours, use this mode to charge the battery can bring the least damage to the battery. In contrast to slow charging, fast charging is an emergency charging method, which uses high-power DC charging (and also AC quick charging), where the DC charging voltage is generally greater than the battery voltage, a large number of li-ion also flows from the battery’s positive electrode to the negative electrode at a very fast and efficient rate to complete the process of fast charging.

In short, the principle of quick charging is like a small bottle which should be filled with the smallest flow of water. In order to reduce the time, you can open it up to the maximum, of course, you can fill it up a lot at once, but such a large flow of water on the bottle is also a great impact. That is, in the case of long-term fast charging, the actual battery voltage is very high, in such a high state of voltage, the battery will be affected.

Let’s take a look at the lithium battery applied in most electric vehicles, this battery is characterized by lightweight, large power. But it also has some disadvantages, that is, if there is a thermal run away in the use process, it may have a safety risk. To get to the point, when the vehicle is being fast-charged, it will put a relatively large current into the battery immediately, which will affect the battery’s ability to restore. The reduction in battery power increases the rate of decay of the battery, which in turn affects battery life and overall performance.

At the same time, the charge-discharge rate of lithium batteries is also worthy of attention. Which refers to the unit rated capacity within the charge and discharge current. When the battery with a rated capacity of 100Ah is charged and discharged with 20A, its charge-discharge ratio is 0.2C. Generally, the charge current of the lithium battery is set between 0.2C and 1C, the higher the current is, the faster the charge is, but at the same time, the heating phenomenon of the battery is also more serious, even leading to spontaneous combustion.

Electric Vehicle battery charge

Although the quick charge has certain harm to the battery, everybody also does not need to worry too much. Because, in order to reduce the damage of fast charging on battery, engineers have invented a very important part —BMS(or Protective Board). For Electric Vehicles, BMS is the core part of quick charging. The main function of BMS is to manage and maintain each cell intelligently, prevent over-charging and over-discharging, prolong the life of the battery and monitor the status of the battery.

In a word, BMS can adjust the pulse width of charging current, intermittent time, and discharge current according to the current state of BMS, and modulate the appropriate current and voltage to complete charging, minimize damage to the battery during fast charging, so the damage is negligible for a limited amount of time.

In general, any quick charge will hurt the battery. But if the battery density, the material, the temperature, the battery management system of the electric vehicle, is properly designed, then the damage is within a reasonable range. If you want to let the battery life is long, as little as possible use fast charge, do not over-discharge and overcharge. If you want to protect the battery, it is better to use slow charge.

Finally, I’d like to share a useful knowledge tip on how to extend battery life. Take 36V 12Ah Ebike battery for example, when daily use, it is better to slow charge. For occasional weekend trips or long drives, there’s nothing wrong with using a quick charge two or three times a week. If you can, make sure your Ebike gets a full charge once a month, which will help with battery life in the long run.

SmartPropel Original Writer:Nancy