A Blended Battery Pack for Cars

Combining different battery technologies could improve vehicle performance and reduce costs.The race is on to find the ideal battery chemistry for plug-in hybrids and all-electric vehicles, but a startup in Indiana believes that a combination of different storage technologies might be the best way to improve vehicle performance and reduce cost. The company's technology allows vehicles to run on a combination of fuel cells, ultracapacitors, and old-fashioned lead-acid batteries.

Smart switch: Indy Power Systems has developed the Multi-Flex Energy Management System, a laptop-size power converter. The system allows makers of plug-in electric vehicles to use a combination of power sources--including lead-acid and lithium-ion batteries and ultracapacitors--and optimizes the blend to increase battery life, improve performance, and reduce cost. Credit: Steve Tolen

Noblesville-based Indy Power Systems has developed an energy management system for vehicles that can quickly switch between two or more energy sources, even when their voltages are different. "It's basically a switch that directs energy in any amount and any direction," says Steve Tolen, chief executive officer and founder of Indy Power, which operates out of Purdue Research Park. "The hardware handles the switching, and the software handles the timing and amounts."

Tolen says that the power electronics package--called the Multi-Flex Energy Management System--is only slightly larger than a laptop computer. He describes it as a custom, software-controlled, DC-to-DC converter that's bidirectional and variable.

"Imagine adding hot and cold water to a tub. We can add a variable amount of hot and a variable amount of cold in different volumes to match the outflow of the drain, which can also be variable," Tolen explains. "In other words, the motor can ask for different amounts of current, and we can provide that, and in different ratios from the two (or more) power sources, regardless of the voltage of the power sources."

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