Nav: Home

EV charging in cold temperatures could pose challenges for drivers

July 31, 2018

New research from Idaho National Laboratory suggests that electric vehicle drivers could face longer charging times when temperatures drop. The reason: cold temperatures impact the electrochemical reactions within the cell, and onboard battery management systems limit the charging rate to avoid damage to the battery.

The new study, which looked at data from a fleet of electric vehicle (EV) taxis in New York City, was posted last week by the journal Energy Policy.

"Battery researchers have known about the degradation of charging efficiency under cold temperatures for a long time," said Yutaka Motoaki, an EV researcher with INL's Advanced Vehicles research group.

But most of the current knowledge comes from experiments with smaller batteries in the lab, not data from large, electric vehicle batteries in real-world conditions. Further, EV manufacturers often provide consumers with only rough estimates of charging times, and they typically do not specify the range of conditions for which those estimates apply.

"We wanted to ask the question: What is the temperature effect on that battery pack?" Motoaki said. "What is the effect of degradation of charging efficiency on vehicle performance?"

Motoaki and his colleagues analyzed data from a fleet of Nissan Leafs operated as taxis over roughly 500 Direct Current Fast Charge (DCFC) events. Temperatures for the charging events ranged from 15 to 103 degrees Fahrenheit.

The researchers found that charging times increased significantly when the weather got cold. When an EV battery was charged at 77 degrees, a DCFC charger might charge a battery to 80 percent capacity in 30 minutes. But at 32 degrees, the battery's state of charge was 36 percent less after the same amount of time.

And, the more the temperature dropped, the longer it took to charge the battery. Under the coldest conditions, the rate of charging was roughly three times slower than at warmer temperatures.

It's important to note that cold weather would only impact EV drivers under specific circumstances, Motoaki said. For instance, people who charge their EVs in a warm garage and use their EVs for commuting within the range of their battery might not experience much inconvenience. Decreased fuel economy in cold weather is also a well-known phenomenon with gasoline and diesel-powered vehicles.

But time spent charging in cold temperatures could make a big difference for a taxi driver, since every minute spent charging a vehicle is a minute the driver is not making money.

"There's a lot of uncertainty about what the vehicle owner's experience would be if they drive the vehicle in Maine or Michigan," Motoaki said.

The research poses questions not only for EV customers, but also for utilities and charging infrastructure providers. For instance, the location or abundance of charging infrastructure may need to be different in colder climates, and electric utilities might see electricity use vary as the seasons change.
-end-
Funding was provided by the U.S. Department of Energy (DOE) Vehicle Technologies Office (VTO).

For more information about electric vehicle research at INL, visit https://www.inl.gov/research-program/transportation-transformation/.

Idaho National Laboratory is one of DOE's national laboratories. The laboratory performs work in each of DOE's strategic goal areas: energy, national security, science and environment. INL is the nation's leading center for nuclear energy research and development. Day-to-day management and operation of the laboratory is the responsibility of Battelle Energy Alliance.

See more INL news at http://www.inl.gov. Follow @INL on Twitter or visit our Facebook page at http://www.facebook.com/IdahoNationalLaboratory.

DOE/Idaho National Laboratory

Related Data Articles:

Discrimination, lack of diversity, & societal risks of data mining highlighted in big data
A special issue of Big Data presents a series of insightful articles that focus on Big Data and Social and Technical Trade-Offs.
Journal AAS publishes first data description paper: Data collection and sharing
AAS published its first data description paper on June 8, 2017.
73 percent of academics say access to research data helps them in their work; 34 percent do not publish their data
Combining results from bibliometric analyses, a global sample of researcher opinions and case-study interviews, a new report reveals that although the benefits of open research data are well known, in practice, confusion remains within the researcher community around when and how to share research data.
Designing new materials from 'small' data
A Northwestern and Los Alamos team developed a novel workflow combining machine learning and density functional theory calculations to create design guidelines for new materials that exhibit useful electronic properties, such as ferroelectricity and piezoelectricity.
Big data for the universe
Astronomers at Lomonosov Moscow State University in cooperation with their French colleagues and with the help of citizen scientists have released 'The Reference Catalog of galaxy SEDs,' which contains value-added information about 800,000 galaxies.
What to do with the data?
Rapid advances in computing constantly translate into new technologies in our everyday lives.
Why keep the raw data?
The increasingly popular subject of raw diffraction data deposition is examined in a Topical Review in IUCrJ.
Infrastructure data for everyone
How much electricity flows through the grid? When and where?
Finding patterns in corrupted data
A new 'robust' statistical method from MIT enables efficient model fitting with corrupted, high-dimensional data.
Big data for little creatures
A multi-disciplinary team of researchers at UC Riverside has received $3 million from the National Science Foundation Research Traineeship program to prepare the next generation of scientists and engineers who will learn how to exploit the power of big data to understand insects.

Related Data Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#514 Arctic Energy (Rebroadcast)
This week we're looking at how alternative energy works in the arctic. We speak to Louie Azzolini and Linda Todd from the Arctic Energy Alliance, a non-profit helping communities reduce their energy usage and transition to more affordable and sustainable forms of energy. And the lessons they're learning along the way can help those of us further south.