Model S owners receive new charging plug to thwart overheating

Tesla is giving new and existing owners of its electric S Model a new wall plug for recharging, along with the latest on-board car software if they don’t already have it. The company says the move is to fight “higher than normal electrical resistance” that could make the charging adapters warmer than usual. The newer plug has a fuse that will stop charging if that begins to happen, something that halts overheating.

A variety of factors such as corrosion, physical damage to receptacles, or inappropriate wiring or installation of electrical outlets can cause higher than normal electrical resistance when using the Universal Mobile Connector (“UMC”) NEMA 14-50 adapters to charge Tesla Model S vehicles. When charging, higher than normal electrical resistance connections to external energy sources may cause excessive heating of the adapter. In December 2013, Tesla released an over-the-air software update to address this issue, enabling the Model S onboard charging system to automatically reduce the charging current by 25 percent if it detects unexpected fluctuations in the input power to the vehicle.