Is Level 2 Charging Bad for Battery?

Like an average smartphone, electric vehicles (EVs) rely on lithium-ion batteries to operate. Li-ion batteries are known for their high power-to-weight ratio, high energy efficiency, good high-temperature performance, long life at high temperatures, and low self-discharge, making them the perfect choice for high-powered and power-hungry devices such as EVs.

When smartphone manufacturers introduced fast charging to replenish handsets quickly, one major concern was its effect on the battery's health. While charging at a higher voltage meant fully charging the battery faster, it also posed potential risks to battery longevity. EV battery manufacturers were also faced with the same issues.

There are three levels of EV charging: Level 1, Level 2, and DC Fast Charging. Level 2 is considered the middle ground, offering decent charging speeds and cost-effectiveness. However, some EV owners remain skeptical about its effects on EV batteries, particularly since it represents a significant jump from the modest 1.2 kW Level 1 charging to 19.2 kW for Level 2. So, is Level 2 charging bad for battery?

What is Level 2 Charging?

Level 2 charging is a popular and relatively faster method of charging electric vehicle batteries. It operates at a higher voltage level compared to Level 1 charging, making it an attractive option for EV owners seeking quicker charging times. Level 2 electric car chargers typically use a 240-volt electrical system, enabling a more efficient charging process.

Benefits of Level 2 Charging

Level 2 charging offers several benefits for EV owners compared to slower charging options. Aside from faster charging speeds, Level 2 charging brings forth additional benefits that contribute to the overall convenience, versatility, and efficiency of EV ownership. Here are some of them:

1. Faster Charging Times

Compared to trickle chargers, Level 2 chargers pose significantly faster charging speeds. This is particularly beneficial for EV owners with busy schedules or those on long trips, where waiting for extended periods for a full charge may not be feasible.

2. Convenience

With the growing infrastructure of public charging stations supporting Level 2 charging, EV owners can conveniently charge their vehicles at various locations. This accessibility adds convenience and flexibility to the EV charging experience.

3. Extended Range

Faster charging times contribute to an extended driving range. EV owners can cover more miles in a shorter time frame, reducing concerns about electric car running out of battery power during long journeys.

4. Cost Savings over DC Fast Charging

While Level 2 charging may not match the ultra-fast charging speeds of DC fast chargers, it is often more cost-effective. The infrastructure costs for installing Level 2 charging stations are generally lower than public charging stations, making it an economical solution for residential and commercial installations. This cost efficiency contributes to the overall affordability of electric vehicles and the whole charging station infrastructure.

5. Home Energy Management Integration

Many Level 2 chargers can be integrated into home energy management systems. This enables users to schedule charging during off-peak hours, taking advantage of lower electricity rates. This feature not only benefits EV owners by reducing charging costs but also contributes to grid stability by distributing energy demand more evenly throughout the day.

The Risks of Level 2 Charging

While Level 2 charging offers numerous benefits, it's essential to be aware of potential risks that may affect the electric car's battery life and overall health.

1. Higher Temperatures

Faster charging generates higher temperatures in the battery. Elevated temperatures can accelerate the degradation of lithium-ion batteries, affecting their longevity and overall performance. Slower charging generates less heat and is better for the EV battery's lifespan.

2. Battery Degradation

Charging at higher voltages may contribute to accelerated battery degradation. Over time, this significant degradation can lead to a reduction in the battery's capacity and overall health, impacting the electric vehicle's range.

3. Safety Risks

Inadequate installation of Level 2 charging stations or non-compliance with manufacturer's guidelines poses safety risks. Electric vehicles are intricate systems, and any deviation from recommended procedures could lead to hazardous situations.

4. Cost Considerations

While Level 2 charging stations offer faster charging, they typically come at a higher cost compared to Level 1 chargers. For some EV owners, the investment in a Level 2 charger may not be justified based on their charging needs and preferences.

Best Practices for Level 2 Charging

To maximize the benefits of Level 2 charging while minimizing potential risks, EV owners should adhere to best practices:

1. Follow Manufacturer's Guidelines

Always adhere to the manufacturer's guidelines regarding charging methods, voltage levels, and recommended charging durations. This ensures that the charging process aligns with the specific requirements of your EV's battery.

2. Qualified Installation

When installing Level 2 charging stations, engage the services of a qualified electrician. Proper installation is crucial to prevent safety hazards and ensure the charging station operates efficiently. Always buy Level 2 chargers from reputable manufacturers and look for products with ETL, Energy Star, and FCC certifications. If you opt for portable chargers, make sure that our existing NEMA 14-50 outlet was installed correctly. For hardwired installations with a home charging station, always consult an electrician.

3. Avoid Frequent Fast Charging

While Level 2 charging is faster, avoid relying on rapid charging excessively. Frequent use of fast chargers may contribute to accelerated battery degradation as it generates excessive heat. For routine charging, consider Level 1 charging, especially when time is not a critical factor. Opting for a slower charging speed is beneficial for EV battery health in the long run.

4. Monitor Battery Temperature

Keep track of the battery's temperature during charging. If possible, choose charging times when ambient temperatures are lower to minimize the risk of overheating. Extreme temperatures may affect battery chemistry, resulting in a decrease in battery performance.

5. Charge Strategically

Plan charging sessions strategically to avoid fully charging the battery regularly. Charging to 80% capacity rather than 100% can contribute to prolonged battery life.

6. Balance the Batteries

Lithium-ion batteries were designed to minimize memory issues seen in older battery technologies. However, EV battery packs are intricate, often consisting of numerous individual cells—sometimes up to 7000 cells—packed into removable modules. Battery balancing becomes crucial to maximize capacity and maintain an even charge distribution.

Modern EV batteries incorporate automatic balancing components. For older models, taking proactive steps can enhance this process. Periodic maximum charges, though not always necessary for daily use, can benefit the battery's management system. A quarterly maximum charge, right before a planned trip, aids in extending the lifespan of the EV battery. However, it's essential to avoid letting the battery sit at full charge for extended periods, as mentioned in the previous section.

7. Use the On-Board Computer

Electric vehicles use advanced technology, featuring high-tech on-board interactive computers. Most modern EVs come equipped with fail-safes and built-in precautions, alleviating concerns about charging operations. Trusting in this technology and familiarizing oneself with its capabilities is crucial for effective battery management.

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