Nokia has launched the first mobile phones to include alerts encouraging people to unplug the charger once the battery is full, a move that could save enough electricity to power 85,000 homes a year.

Starting with the new Nokia 1200, Nokia 1208 and the Nokia 1650, the alerts will be rolled out across the Nokia product range.

Kirsi Sormunen, vice-president of environmental affairs at Nokia said, "Around two-thirds of the energy used by a mobile phone is lost when it is unplugged after charging but the charger itself is left in a live socket. We want to reduce this waste and are working on reducing to an absolute minimum the amount of energy our chargers use. The new alerts also play an important role, encouraging people to help us in this goal by unplugging their chargers".

The alerts are one of a series of environmental initiatives that mobile manufacturers, led by Nokia, agreed to take action on this year. Nokia is the first of these manufacturers to implement the alerts into its products.

Nokia has decided to put the alerts into mass market products first to help maximise the potential energy savings. The Nokia 1200, Nokia 1208, Nokia 1650 are targeting high volumes of sales in fast growing markets like India, China and Latin America.

The company has set ambitious goals to further reduce the energy consumption of its chargers. By 2010 it aims to have reduced by an additional 50% the amount of electricity a charger consumes whilst still plugged into the mains but not the phone.