EV Batteries: Promise of An Afterlife

You have your solutions, and then there are elegant solutions.

The “solution” is an electric car itself, such as a Chevy Volt, Spark EV, Nissan Leaf, etc., but the “elegant solution” could be maximizing the value and fleshing out a complete cradle-to-grave and beyond paradigm for post consumer batteries.

As a case in point, Nissan and GM are working with ABB Group seeking ways to practically re-use EV batteries in energy storage systems which maximize value of an otherwise post-lifecycle car battery, and add to the renewable energy grid. By definition, EV batteries are deemed post life when their charge holding capacity is somewhere around 70-percent depleted and they cannot meet a sufficient range compared to the new EV.

At the same time, there may be a monetary payback for the depleted battery in years to come, thus lessening the sting of the EV’s price tag for the consumer who may even be able to sell off his old battery to offset the cost of a new one.

“From an environmental picture standpoint, you need to think about the sustainability of everything you’re doing. You need to focus on the broader picture,” said Pablo Valencia, GM senior manager of battery lifecycle management in an interview with Automotive News. “What we’re doing right now is preparing for that broader picture — getting awareness up, both from a customer standpoint and also an industry standpoint, so that the energy storage industry is thinking about secondary use.”

Valencia said he expects within 10 years time the bugs will be worked out of energy storage prototypes just now being demonstrated, and infrastructure will be in place to accept used EV batteries, check their level of performance capacity remaining, and re-purpose them into stationary energy storage units.

“That’s where the world will be,” Valencia said. “People will understand how to use them.”

One of the “bugs” will be software and algorithms to make it a reality.

“One of those key pieces is the controls and the ability to charge the batteries up evenly at cell level, at a section level and an overall system level. Keeping all that balance in place is really the secret sauce to making any battery system work whether it’s a new battery system or a secondary-use battery system,” Valencia said. “The bigger the system is, the more important it is to keep it playing like a good orchestra with all of the pieces in balance with each other.”

Those working in this research field say EV batteries will not be able to be mixed. That is, only the same type of battery must be used, and so you will not likely find a Volt battery mated with a Leaf battery, and a Tesla battery, for instance.

“Batteries that are going into the Volt, for example, are different than the ones going into the Leaf. They are different than what’s going into the Tesla,” Portland General Electric’s Allcock said. “Batteries have all kinds of characteristics. You can’t mix and match on battery packs from different vendors. It just doesn’t work that way.”

Automotive News