Wireless battery technology was unveiled at this year's International Consumer Electronics Show by Powercast LLC, promising to set consumers free from power cables and heavy power adapters.

The company claims its Powercaster and Powerharvester modules can recharge batteries in consumer devices smaller than a cellphone using RF broadcasts from up to a meter away.

Although experiments with wireless power transmission date back to the 19th century, We're introducing the first way to send power through thin air, says Powercast CEO John Shearer.

Using the 900-MHz band, Powercast transmists RF energy to a receiver module measuring about half the size of a AAA battery.

The firm said it tested its technology at the Pittsburgh zoo. The Powerharvester receiver module was retrofitted to the battery compartment of a wireless sensor made by extending battery life from under 120 days to several years.

Powercaster said it has received FCC approval for its technology, which includes a family of energy beacon transmitters and receivers. Development began in 2003.