Tech Question of the Week: What information is available on electric vehicle (EV) battery degradation due to different charging speeds?

Response From: National Renewable Energy Laboratory (NREL)

Question: What information is available on electric vehicle (EV) battery degradation due to different charging speeds?

First, for general information on the expected life cycle of an EV battery, please refer to the Department of Energy’s At A Glance: Electric-Drive Vehicles fact sheet (https://afdc.energy.gov/files/u/publication/electric-drive_vehicles.pdf). Specifically, see the maintenance section for information on battery life:

“Electrical systems (battery, motor, and associated electronics) require minimal scheduled maintenance. A manufacturer’s warranty of a battery typically covers 8 years/100,000 miles. Expected battery lifetime is 12–15 years under normal operating conditions.

Next, it is our understanding that while EV batteries may degrade faster with the use of direct current (DC) fast charging compared to the use of Level 2 charging, the difference is minimal.

 This study compared four new 2012 Nissan Leaf EVs, two of which were charged exclusively by Level 2 chargers and two of which were charged exclusively by DC fast chargers. The conclusion of the report states the following:

A greater loss in battery capacity was observed for the fast-charged vehicles, though the difference compared to the level two charged vehicles was small in comparison to the overall capacity loss. The vehicle operation was, as intended, verified to be very similar between test groups, and the largest difference in conditions noted was battery temperature during charging. Hotter ambient temperatures appear to have accelerated capacity loss for all of the vehicles in the study, though the exact relationship remains to be seen.”

 

Further, a 2020 Geotab study of 6,300 EVs showed similar results to the above INL report (https://www.geotab.com/press-release/ev-battery-degradation-tool/):

“The use of DC fast chargers appears to speed up the process of degradation but there is not much difference in battery health based on frequent use of Level 1 versus Level 2 charging.”

Lastly, in 2023, Recurrent studied the battery management systems of 12,500 Tesla vehicles in the US and found that there was no significant difference in range degradation or battery damage when relying on fast charging versus level 2 or 1 charging. You may refer to the Recurrent article Full Speed Ahead: EV Study Reveals Impacts of Fast Charging (https://www.recurrentauto.com/research/impacts-of-fast-charging) more information on their results.

Battery Degradation Tools

NREL’s Battery Lifetime Analysis and Simulation Tool (BLAST) Suite (https://www.nrel.gov/transportation/blast.html) combines NREL’s battery degradation modeling with electrical and thermal performance models in order to assess battery lifespan and performance for behind-the-meter, vehicle, and stationary applications. BLAST tools incorporate realistic lab-based drive-cycles or simulated real-world driving patterns to anticipate EV battery lifetimes. In particular, BLAST-Lite (https://github.com/NREL/BLAST-Lite), which is available online, provides a library of battery lifetime and degradation models for various commercial lithium-ion batteries from recent years.

Further, Geotab offers a tool from 2020 comparing battery degradation of different EV models (https://www.geotab.com/blog/ev-battery-health/). Please note that we cannot verify the accuracy of nongovernmental resources. You may filter by model, model year, or add multiple models to compare the vehicles’ estimated battery degradation. This tool was developed from the study of 6,300 fleet and consumer EVs referenced above.

Clean Cities Celebrates 30 Years of Advancing Sustainable Transportation Solutions

From the DOE Office of Energy Efficiency and Renewable Energy

September 7, 2023

Clean Cities Celebrates 30 Years of Advancing Sustainable Transportation Solutions

DOE-funded initiative boosts national energy security, economic vitality, and quality of life   

Clean Cities, composed of 75 coalitions across the country, is celebrating 30 years of boosting the national energy security, economic vitality, and quality of life. Launched in 1993 by the U.S. Department of Energy (DOE), Clean Cities coalitions work in urban, suburban, and rural communities throughout America helping businesses and consumers meet climate, financial, and energy goals through sustainable transportation fuels and technologies.

“We are so proud to be celebrating 30 years of such important and impactful work,” said Michael Berube, DOE Deputy Assistant Secretary for Sustainable Transportation and Fuels. “For three decades, Clean Cities has been a trusted partner, providing people across the country with the best information and knowledge on the latest clean transportation technologies.”

Through projects focused on increasing vehicle efficiency, shifting to alternative energy sources, and offering consumers additional transportation choices, Clean Cities coalitions have saved the equivalent of 13 billion gallons of gasoline and prevented more than 67 million tons of emissions from polluting America’s skies.

“Coalitions work in their communities to understand local priorities and offer resources and expertise backed by real-world experience,” said Mark Smith, Technology Integration Program Manager for DOE’s Vehicle Technologies Office, which oversees the program. “Clean Cities is transforming transportation by bringing the latest technologies to the streets and providing technical assistance with lasting, meaningful results.”

The anniversary features celebrations near Washington, D.C. mirroring local events across the country that highlight decades of work building bipartisan support and forging deep connections within the transportation industry. To date, Clean Cities coalitions include active partnerships with more than 20,000 public and private stakeholders. Thriving on a culture of collaborative change, coalitions harness decades of deployment expertise to advance sustainable transportation systems.

The origin of Clean Cities dates to the passing of the Alternative Motor Fuels Act of 1988 and the Clean Air Act Amendments of 1990. These laws, which encouraged the production and use of alternative fuel vehicles (AFVs) and the reduction of vehicle emissions, led to the creation of the Alternative Fuels Data Center (AFDC) in 1991. The AFDC’s initial objective was to collect, analyze, and distribute data used to evaluate alternative fuels and vehicles.

The Energy Policy Act of 1992 (EPAct) required certain vehicle fleets to acquire AFVs. Subsequently, DOE created Clean Cities in 1993 to provide informational, technical, and financial resources to EPAct-regulated fleets and voluntary adopters of alternative fuels and vehicles.

For more information, please visit https://cleancities.energy.gov/.