Infinite Power Solutions' tiny batteries just got a little bit better.

The Littleton, Colo.-based company announced a technology breakthrough this week, saying it has boosted the discharge capacity of its "micro energy cell" devices significantly.

"We've demonstrated in excess of 3 milliamp hour," said Ray Johnson, CEO. That's a big deal for an industry that once thought reaching 1 milliamp hour of discharge capacity was beyond the technology's reach, he said.

Infinite Power already has a prior line of solid-state micro energy storage devices in that 1 milliamp hour range out to customers including Lockheed Martin, which formed a partnership with the company last year, Johnson said.

But increasing the discharge capacity – in layman's terms, the amount of electricity that can be stored – of its devices could provide a boost to the company's efforts to broaden the customer base for its postage-stamp sized batteries, he said.

Johnson wouldn't say how much Infinite Power's energy storage devices cost, but conceded they're more expensive than alternatives like coin cell batteries, which can cost 20 to 40 cents apiece in bulk.

Still, Infinite Power's "Thinergy" devices can serve an important role in powering devices like wireless sensors, radio frequency identification (RFID) tags and other devices, Johnson said. That's because replacing batteries on those distributed, often-mobile devices can cost much more than the extra cost of thin-film batteries, which can last far longer than cheaper alternatives, he said.

"The cost of changing out a battery can range anywhere from $5 at the consumer level to $150 if you have to roll a truck and climb up on a bridge to change a sensor for an infrastructure project," he said.

Thin-film batteries' advantages are especially pronounced when combined with "energy harvesting" technologies that can capture ambient vibrations, radio waves or thermal energy to generate tiny amounts of electricity, he noted (see Intel's Power Play: Charging Gizmos in the Air).

Infinite Power is working with companies like Hampton, Va.-based AdaptivEnergy, which makes vibration-based energy harvesting technology, and Pittsburgh-based PowerCast, which makes devices that capture energy from radio waves, Johnson said.

The company has raised about $50 million since 2006 from investors including Polaris Venture Partners, Applied Materials' venture capital arm Applied Ventures, and In-Q-Tel, the CIA's venture arm (see A Battery for Perpetual Motion), and recently opened its commercial-scale factory.

While it is now testing its products with government contractor clients, it is in talks with makers of consumer electronics, Johnson said.

Infinite Power is among a number of companies, including Planar Energy Devices and Cymbet Corp., working on commercializing thin-film battery technology (see Can Thinner Batteries Be Better?).

Last month, Planar Energy Devices came out with its own improved lithium-ion battery with a capacity of 10 milliamp-hours combined with a kit to harvest energy from radio waves. And Cymbet's thin-film batteries are being used in a Texas Instruments kit meant to convert light into power to keep wireless sensor devices permanently charged. 

But Infinite Power's solid-state technology differs from those other companies, which use more traditional lithium-ion liquid chemistries, said Jay Whitacre, a professor at Carnegie Mellon University who has worked in the thin-film battery field for a decade.

The key difference is in the number of times a solid-state energy storage device can be charged without losing capacity, he said.

"You can get tens of thousands of cycles off one of these solid state systems," he said. "You cannot get that many cycles off an electrolyte"-based battery.

This distinction could help Infinite Power stay ahead of the competition if it keeps boosting the capacity of its batteries, said Elaine Chan, research analyst for Frost & Sullivan.

"Capacity improvement is crucial and has been a technical challenge in the industry," Chen said in an email. "Achieving high capacity will make the batteries run longer and potentially increase the attractiveness of thin-film batteries."

As for where those capacity increases might end, Johnson remained optimistic.

"There may be a physical limit of this technology," he said, but "we haven't hit it yet."