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What factors affect the EVs charging speed

What factors affect the charging speed of EVs?

If you are looking for EVs lithium battery in your project, there is no doubt that the charging process will be at the forefront of your considerations. Charging an electric car is not as straightforward as refueling a gas-powered vehicle and it’s important to understand how the entire charging process works. With advancements in technology, faster charge times are possible but there are numerous factors that affect your charging speed and overall efficiency when using different kinds of chargers. In this blog post, we will delve into all of these elements so that you can make an informed decision when looking for EVs lithium battery in project.

Overview

1. What is the process of EVs battery charging?

2. How does charging speed varied in charging process?

3. What factors affect charging efficiency?

1. What is the process of EVs battery charging?

When it comes to “charging”, there is often a distinction between “fast charge” and “slow charge”. The fast-charging time varies slightly among different vehicles, and the specific charging process can be found in the manufacturer’s published data. The charging process is not simply a physical connection between the charging gun connector and the socket.
Fast charging generally involves six steps.

The first step is physical connection, beside it there are also:

Low voltage auxiliary power on: The charging station provides low voltage auxiliary DC power to the electric vehicle to activate the BMS

Charging handshake: The vehicle and the charging pile send a “handshake” message to each other to obtain the charging-related parameters of both parties.

Charging parameter configuration: The charging pile and the vehicle side are matched with basic parameters such as the maximum charging demand power of the vehicle and the maximum output power of the charging pile to ensure the “adaptation” of both parties during the subsequent charging process.

Charging: The built-in BMS of the electric vehicle will send charging power demand information to the charging station, and the charging station will adjust its output voltage and current in real-time based on this information to ensure the smooth charging process. At the same time, they will monitor each other’s charging status in real-time to ensure charging safety.

From the charging process, we’ll find that the “fast charging” process of electric vehicles is actually the process of real-time interaction between the BMS and the charging station, controlling the output voltage and current of the charging station. Just like a person who is thirsty and needs to drink water, how much water they drink and how fast they drink depends more on the degree of thirst and the ability of the drinker to drink water.

2. How does charging speed varied in the charging process?

If we carefully observe the charging process of the power battery, we will find that the charging speed of the battery is not linear, and the charging speed varies with different remaining battery values. The speed of car charging can be roughly divided into three periods, with the first 20% being the fastest, the middle 20% -80% being faster, and the last 20% being slower.

What factors affect the EVs charging speed

After about 10 minutes of starting charging, the battery is in the preheating stage, and the battery activity gradually increases. In this state, the required charging power of the battery gradually increases, and the charging speed is also constantly accelerating.
When the SOC reaches 50% to 60% (with slightly different car models from different brands), the power demand is like sitting on a “happy slide” and begins to decline, naturally slowing down the charging speed.

When the SOC reaches 95%, the battery is almost fully charged. In order to protect the safe charging of the battery during operation, the BMS system will intervene and the charging station will charge at a lower power to protect the health of the car battery and ensure charging safety.

What factors affect the EVs charging speed

From the perspective of the entire charging process, the charging power required for power batteries varies at different stages. Generally speaking, if the SOC is between 20% -80%, the charging speed will be faster, and the overall trend is from fast to slow.

3. What factors affect charging efficiency?

In addition to the control strategy from electric vehicle BMS, the speed of charging is also related to factors such as charging stations, vehicle power, battery SOC level, environment etc.

What factors affect the EVs charging speed

Charging Pile Power

The higher the output power of the charging pile, the shorter the charging time. Charging is the process in which the charging pile responds to the charging power of an electric vehicle. When the voltage platform at the vehicle side is higher than the charging pile voltage platform, the charging pile will not be able to charge the electric vehicle. Meanwhile, when the maximum output power of the charging pile is lower than the charging power required by the electric vehicle, the electric vehicle cannot achieve the expected “fast charging”. The input power that different cars can accept varies, and some models determine the power of the car, which can make the user experience of the same charging piles different.

Battery capacity

When the output power of the charging pile is the same, the higher the power of the vehicle’s power battery, the longer the charging time. This is like injecting water into a pool through a drain pipe of the same caliber. The larger the pool, the longer it takes to fill it with water.

Current battery SOC level

Car battery manufacturers also consider the actual needs of users when producing batteries, so they have designed the charging time when the battery is low. The amount of battery charge is inversely proportional to the charging rate, which means that the lower the battery charge, the shorter the charging time.

What factors affect the EVs charging speed

Environmental Temperature

The speed of battery discharge is also affected by the surrounding temperature, for example, charging a car in winter will significantly take longer than in summer. There is also a phenomenon that the car cannot charge or the charging speed is maddeningly slow in very cold Winters. What is the reason for this? This is related to the chemical characteristics of the battery itself, which is called low-temperature protection. When the temperature is too low, the metal lithium in the battery will deposit and no longer react with the substance, resulting in internal short circuits in the battery.

The lower the battery temperature, the lower the chemical activity of lithium-ion batteries, the slower the charging speed, and it is difficult to fully charge. After scientific calculation, the optimal discharge temperature for general automotive batteries is around 25 degrees Celsius. 

To wrap things up, it is important to understand the entire process of EVs battery charging and the variables that influence it. As we have seen, there are several factors involved in making sure your electric vehicle charges at the desired speed and efficiency so it’s wise to carefully consider all these elements when selecting an EVs lithium battery for your project.

Ultimately, it is essential to approach a reputable manufacturer who will be able to advise and provide experience in supplying EVs lithium batteries. Here at Bonnen Battery, we stand out amongst our competitors due to our dedication towards providing premium quality products and delivering an unparalleled customer service experience- so don’t hesitate to get in contact with us! We’ll be more than happy to answer any questions or queries that you may have regarding your future projects when it comes to EVs lithium battery.

Contact Bonnen Batterynow and learn more about EVs lithium battery Technologies!

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