Nokia is testing a new solar charging accessory in Nigeria and Kenya, as the company hopes to make it easier for people without regular access to electricity to use their phones.

The Portable Solar Charger DC-40 can turn one minute of charging into two minutes of talk time, according to Nokia.

The charging mat uses a thin-film photovoltaic panel, weighs 93g and has a 3m cable to connect to the phone via Nokia's standard 2mm plug.

This isn't the first time Nokia has tested the potential of solar charging. In January this year the company reported on a research project that placed a solar charger on the back of a phone.

Problems with that included the limited size of a phone's back cover, which restricted the size of the panel, and the extent to which the battery could be charged, Nokia said at the time. Few people can leave their phone lying in the sun all day while it charges.

Nokia's first attempt at a solar-powered phone came in 1997, when it launched the Nokia 1610 Plus with an optional lithium-ion-and-solar-panel battery. More recently, vendors such as Samsung Electronics and LG Electronics have introduced smartphones with a solar panel on the back cover. The Samsung S7550 Blue Earth and LG GD510 Pop were both announced in 2009.

By using an external charger this time around, Nokia can give the charger a much larger surface to capture sunlight.

The previous research project's best results were recorded in Kenya, which once again, along with Nigeria, will be used as a proving ground.

Kenya and Nigeria provide the perfect opportunity for testing the DC-40, Nokia said, citing data from the World Bank that indicated that only 16% of Kenyans and 51% of Nigerians had regular access to electricity between 2007 and 2011.

The pilot will study the product's business potential, usage patterns and environmental and social impacts, according to Nokia.

Sales of the DC-40 will start this week.