Is DC fast charging bad for your EV battery?
Many studies have shown that frequent use of DC chargers will cause certain damage to the car battery. Some car manufacturers like Tesla and Ford have also issued such warnings, but do DC chargers really have such a large loss on the car?
Yes, it is. When you use the DC EV charger to rush to 100%, frequently and in unhealthy use, it is a fact that causes some damage to your car battery. If you follow this guide to use the DC EV charger correctly, you don’t have to worry about these problems.
What is the dc fast charger?
Before telling the reason, let’s clarify what the DC EV charger is and how it works.
Unlike AC chargers, which supply power at a fixed voltage and current, DC chargers can deliver high-power direct current to the vehicle battery. They typically provide a constant DC voltage (such as 200V or 400V) and complete an 80% charge in half an hour to an hour, with the amount of current depending on the capacity and changeability of the vehicle’s battery.
How does it work? A DC charger first converts AC power from an external source (usually the grid) to DC through rectifier or power electronics. This conversion process ensures that the charger can provide the required DC power to charge the EV battery.
I have described the concept of a DC EV charger and how DC EV charger work in detail in other articles, click to read.
Is it bad for your car’s battery?
DC fast charging can have an impact on your electric vehicle (EV) battery, and it’s important to understand the potential effects:
- Heat Generation
DC fast charging involves delivering a high amount of electrical current to the battery, which can generate heat. Excessive heat can degrade the battery’s performance and potentially shorten its lifespan.
However, modern EVs are equipped with battery management systems (BMS) that monitor and regulate the temperature during charging to minimize the negative effects of heat.
2. Battery Degradation
Fast charging, including DC fast charging, can contribute to battery degradation over time. The rapid charging process can cause chemical reactions within the battery that lead to wear and capacity loss.
However, the extent of degradation depends on various factors such as battery chemistry, temperature management, charging protocols, and the specific design and capabilities of the EV’s battery system.
3. Charging Efficiency
DC fast charging may have lower charging efficiency compared to slower charging methods. As the battery reaches higher states of charge, the charging speed may slow down to protect the battery and maintain its long-term health.
The charging efficiency can also be influenced by factors such as temperature, battery condition, and the specific charging protocol used.
4. Battery Longevity
Frequent use of DC fast charging, particularly if done at high power levels, can contribute to increased wear on the battery and potentially reduce its overall lifespan. However, the impact on battery longevity can vary depending on factors like the specific battery chemistry, the manufacturer’s design, and the vehicle’s thermal management system.
Geotab has also done corresponding research on this. Compared with drivers who never used fast charging, fast charging more than three times per month could lead to a 0.1% increase in battery degradation, the findings showed. Although the increase is relatively small, long-term accumulation may have a certain impact on the capacity and performance of the battery.
In fact, whether it is AC or DC charging, it will cause some damage to the car over time, but compared with AC, using DC direct current charging will cause the battery to wear out faster.
In my opinion, although DC charging will cause some damage to the car battery, the final consumption depends on how you use it.
If you use DC EV charging frequently and regularly and rush to 100%, it will indeed cause some damage to the battery over time. But if it’s just a vacation trip, using it once in a while and only charging it to 80-90% won’t do your car any harm. So, use it sparingly and don’t worry about it.
Battery technology continues to advance, and manufacturers are continuously improving battery chemistry, thermal management systems, and charging algorithms to optimize performance and prolong battery life.
How to reduce these negative effects?
To mitigate the wear and tear on your vehicle caused by DC fast charging, you can consider the following:
- Charging Speed and Power
When using DC fast charging, try to adhere to the recommendations provided by the vehicle manufacturer and avoid using excessively high charging power. The lower charging power can reduce the heat and stress generated during charging, helping to slow down battery degradation.
2. Charging Frequency and Depth
Avoid excessively frequent and deep charging cycles. Frequent charging and deep discharging can accelerate battery degradation. Aim to keep charging at a moderate frequency and depth, avoiding extreme states of charge.
3. Temperature Management
Maintain the battery within an appropriate temperature range. High or low temperatures can accelerate battery degradation. If possible, avoid fast charging in extreme temperature conditions.
4. Charging Strategy
Choose different charging strategies based on your needs and flexibility in charging time. For example, when you have more time available, opt for slower alternating current (AC) charging and reserve DC fast charging for specific circumstances.
5. Smart Charging Controls and BMS
Modern electric vehicles and battery management systems (BMS) often feature smart charging controls that optimize the charging process and maximize battery protection. Follow the recommendations provided by the vehicle manufacturer and leverage the functionality of the BMS to ensure the battery receives a reasonable and safe charge.
6. Maintain an Optimal State of Charge
Try to avoid charging the battery to excessively high or low levels. Keeping the battery within a moderate state of charge range helps reduce stress and degradation during the charging process.
7. Charger Selection
Choose high-quality and reliable chargers. Certified and compliant charging equipment generally provides a more stable and reliable charging experience, minimizing potential damage to the vehicle battery.
It’s important to note that these are general recommendations, and the specific methods to mitigate wear and tear from DC fast charging may vary based on the vehicle manufacturer’s recommendations, charger specifications, and the characteristics of the vehicle itself.
Following the charging guidelines and recommendations from the vehicle manufacturer and having a good understanding of the charging equipment and battery system will help optimize the charging process and protect the vehicle’s battery.
FAQ
F: How often should I use a fast charger for my EV?
Q: Best not to, regular use can damage battery life.
F: Is Level 2 charging bad for batteries?
Q: Level 2 charging is generally not considered bad for batteries. In fact, Level 2 charging is one of the most common and widely used charging methods for electric vehicles (EVs) and is considered safe and efficient.
F: How many kwh is DC fast charging?
Q: To determine the specific amount of energy (in kWh) consumed during DC fast charging, you would need to multiply the charging power (in kW) by the charging time (in hours). For example, if you use a 100 kW DC fast charger for 0.5 hours, the energy consumed would be 100 kW * 0.5 hours = 50 kWh.
In conclusion, DC fast charging has potential impacts on EV batteries, but implementing a sensible charging strategy, temperature management, and adhering to EV manufacturers’ recommendations can minimize these effects. A balance should be struck between charging speed and battery health, ensuring safety and reliability during the fast charging process.
