THE surge in the popularity of mobile phones could cause major problems in the battery industry. That's according to a study carried out by the aptly named Powers Associates, a US consultancy firm.

It has found that a big rise in Japanese output of new lightweight batteries, which are suitable for use in mobile phones and other equipment, could end up with the industry being in oversupply by the end of the century. Production capacity for the new batteries is likely to virtually treble by the year 2001, it says.

Apparently the US and Japan are the biggest markets for batteries of all types.