"We've been selling zinc air batteries for 30 years for hearing aids, but this is our first use of the chemistry for consumer devices," said Jon Eager, director for OEM marketing at Energizer (St. Louis).

In early tests, a quadruple A-sized zinc air prismatic battery delivered 38 hours of run time at 50 milliwatts compared to about 12 hours for similar sized alkaline batteries. The zinc air products delivered twice the energy density of disposable alkaline cells and much lower costs than rechargeable lithium ion alternatives.

Nevertheless, Energizer faces several challenges commercializing the technology. Startup AER Energy tried and failed to develop viable zinc air batteries for laptop computers several years ago.

For the smaller devices Energizer targets, zinc air cells cost about 50 cents each compared to less than 15 cents for alkaline button cells. That's due to the relatively complex manufacturing process for the prismatic zinc air cells.

In addition, Energizer must create a simple, low cost way to manage air flow through the zinc batteries to deliver the right flow of oxygen the cells require. The current design uses air access holes which are sealed with a tab until the consumer is ready to use the battery. The company also aims to use inexpensive valves and other techniques to throttle air flow as needed to match the needed discharge rate of a given device.

The company also must get OEMs to agree on standard sizes for the zinc batteries so Energizer can sell the batteries in volume at retail. So far, the company has defined three sizes--a quadruple A, a triple A and a smaller size, all using a new 5mm thick rectangular cell.

"We don't think anyone else is doing zinc air in these sizes, but our hope is eventually other battery companies will use this as well," said Eager. "Our intention once product ships is to go to standards groups and propose these three sizes as a standard," he added.

Energizer is still seeking feedback from about six unnamed OEMs on the new sizes. If support and design wins gel around specific sizes, products could ship as early as June.