Send SMS to charge your cellphone Out of battery? Just send a text! People living off-grid can now power their phones simply by sending a text message.A London-based company Buffalo Grid has introduced a solar-powered cellphone charging station that is activated by text message.A patchy or absent power grid poses a conundrum of problems for rural areas in the developing world, particularly in Africa and Asia, where the use of cellphones is rapidly rising. The company's basic technology, which was recently trialled in Uganda, should help tackle this issue, 'NewScientist' reported.The battery extracts power from the solar panel using a technique called maximum power point tracking (MPPT). A 60-watt solar panel charges a battery.A solar panel's power output is dictated by environmental conditions, such as temperature and the a...