ECU engineering drives research into reuse of hybrid vehicle batteries

When the battery in your TV remote goes bad, you simply throw it away. When the battery in your hybrid vehicle goes bad, you start a research project.

Dr. Jason Yao, engineering professor and associate dean for academic affairs in East Carolina University’s College of Engineering and Technology, is exploring how to improve testing of hybrid vehicle batteries to provide better options for their reuse.

Aiden Sugg tests a hybrid vehicle battery cell in the Science and Technology Building. Sugg and Dr. Jason Yao are researching improved testing methods that could be more cost effective.

As the owner of two hybrid vehicles, Yao became curious when he had to replace the batteries on his own cars.

“These batteries, they have their first life being utilized on the EVs (electric vehicles),” Yao said. “Once they’re lower than a certain threshold, they’re not good enough for the first life but then they can be used for second lives.”

He said though the batteries may not be good enough for the vehicle anymore, they can still serve as a power source, perhaps for golf carts, e-bikes or data storage.

Yao said the problem is that the testing of these hybrid batteries to determine viability is a time-consuming, costly endeavor.

“Inside the battery pack, there are so many modules, and then inside a module, there are so many cells. And each cell, a lot of times, the residual capacity is different,” Yao said. “So, in order to figure out which batteries are good for what purpose, it’s a challenge. You cannot really afford to spend the time and money to check each cell.”

Yao said his hybrid vehicle has 28 battery modules with 168 cells. Each cell’s location in the module affects its life based on thermal characteristics that induce degradation. The goal of the project is to create a “battery triage” method that — based on each cell’s location — could be used to determine tiers of second-life battery suitability using minimal, and thus less costly, direct testing.

To the Lab

Inside a room on the third floor of the Science and Technology Building, engineering major Aiden Sugg looks over a slew of cables and meters. The rising senior saw Yao’s project proposal this spring, and within a week, they submitted a request for $1,500 in funding to begin the work.

“These batteries have a lot of usable capacity that can be retained,” Sugg said. “It’s just really important that we find a cost-effective way to make the reuse and recertification of those accessible because the limitation right now is cost and time.”

He started work this summer on the first phase of what is a submitted two-year project to build a physical system that charges and discharges EV batteries and includes parameters such as cell temperature.

Aiden Sugg said he enjoys the research process and is learning a lot about power systems as he explores hybrid vehicle batteries.

“The most exciting thing about this project is that we are doing everything from the ground up. Unfortunately, that means we are doing everything from the ground up,” Sugg joked.

The first step is to collect data related to battery degradation, which means the use of sensors to test battery temperature during controlled charging and discharging cycles. Electrical and thermal data, battery pack voltage and current, temperature histories, and the amount of energy that flows through the battery will be collected.

“A big part of what I’ve been doing is not so much testing the batteries but learning how we’re going to test the batteries,” Sugg said of his work this summer.

He said what some may see as tedious work is actually an opportunity.

“Oh, it’s the learning,” Sugg said. “It’s a lot of just coming in and plugging in a cable and seeing if it works, seeing if it doesn’t. And that’s actually my favorite part, getting to learn about how these things interface.”

With a concentration in electrical engineering, Sugg said the project aligns perfectly with his career goals and will help him land a job as an electrical engineer when he graduates in 2027.

“The great thing about this work is it’s very applicable to so many different industries and so many different fields of electrical engineering because it really is dealing with a bunch of different power systems,” said Sugg, a Winterville resident who transferred to ECU from Pitt Community College. “I’m working with these tiny little boards that have integrated processors. I’m learning how to use our computers to interface with the power supply and do data acquisition, data management and record keeping, which is very important.”

Plus, he gets charged up about the batteries themselves.

“They’re magic,” he said. “They’re a whole special thing.”