Tesla will provide Model S owners with improved charger connectors, following a half-dozen incidents in which wall plugs melted or smoked while vehicles were recharging. The redesigned adapter includes a thermal fuse designed to shut off charging if overheating is detected.

Overheating can stem from inadequate household wiring, said Elon Musk. Tesla has already sent out a software update that reduces charging current by 25% when it senses conditions that could lead to overheating. The company isn’t aware of any overheating incidents since the software update. “We’re highly confident the software update addresses overheating issues,” Musk said. “These are very rare events, but occasionally the wiring isn’t done right. We want people to have absolute comfort, so we’re going to be providing them with an upgraded adapter.”

The replacement adapters are expected to cost “a few million dollars” and have no material impact on earnings, said Liz Jarvis-Shean, a company spokeswoman.

At least six overheating incidents have been reported on the Tesla Motors Club forum. One Model S owner reported that “plumes of smoke” came from his adapter, which fused to the charging cord. Another reported burning his hands and arm trying to remove his charging cord after smelling melting plastic.

There are five reports of Model S cord and plug overheating in NHTSA’s consumer complaint database. Tesla has informed NHTSA of the overheating incidents, the software update and the new charger adapters, Musk said.

“NHTSA is monitoring reported fires associated with certain Tesla Model S charging cords and adapters and will take appropriate action as necessary,” said agency spokesman Nathan Naylor.

Source: Bloomberg