Questions are being asked about the safety of the lithium batteries used in iPods after a customer in Japan reported an incident where their iPod gave off sparks. The Apple iPod nano started emitting sparks whilst it was being recharged. The problem was put down to the battery used in the device. A spokesman for Apple has said that the company is aware of the incident but that no one was available to comment. Japan’s government has ordered Apple to investigate the incident which affected the older Apple iPod nano with the model number MA099J/A. Apple has previously warned that iPods might overheat while being charged in certain carrying cases. Information on its website advises: “Charging your iPod, iPod nano or iPod shuffle while in certain carrying cases may generate excess heat, which can affect battery capacity.