Reuters is reporting that the world's top five cellphone vendors launched a common energy rating system for chargers on Wednesday, with the goal of making it easier for consumers to figure out which ones consume the least amount of energy.

The move aims to reduce criticism from environmentalists, now that cell phones make up the largest portion of the consumer electronics industry.

Right now, about two thirds of the electricity used by cell phones is wasted energy due to chargers being left plugged into walls while disconnected from handsets.

"The new ratings system covers all chargers currently sold by Nokia, Samsung, Sony Ericsson, Motorola and LG Electronics, and ranges from five stars for the most efficient chargers down to zero stars for the ones consuming the most energy," according to the report.