Tesla isn't relying on software alone to reduce garage fire risks for Model S owners. The automaker will soon offer drivers a free, upgraded wall charging adapter with a thermal fuse. The new device will cut electricity when it detects overheating, even if circuit breakers in the car or house don't intervene. Both new and existing Model S owners should start receiving new adapters within weeks, Tesla says. While the company doesn't believe that the chargers are necessary to minimize the danger to customers, it doesn't want to leave anything to chance -- even if it's prepared for the worst.