Two new heat-resistant batteries have been introduced by Maxell Corporation of America for use in onboard tire pressure monitoring systems being readied to meet new Federal rules mandating automatic warning of faulty tires. The new Lithium Manganese Dioxide coin cells power pressure-sensing tags, which mount on the rims of each vehicle's wheels. The new designs include a change in gasket material, a totally new crimping structure and improved content to operate in the high-temperature environment encountered on rotating auto and light truck wheels.