Portable Car Starters Can Be Dangerous at High Temperatures
From Consumer Reports
Heat can be dangerous. According to the National Highway Traffic Safety Administration (NHTSA), the temperature inside of a car parked in direct sunlight can reach between 131 and 172 degrees Fahrenheit when the temperature outside is between 80 and 100 degrees. In hot desert areas, the inside temperature can rise even higher.
Unfortunately, device manufacturers are guarded on the potential consequences of storing these units at high temperatures. Complicating matters, it's the fact that most of the units list their temperature ranges (operating or storage) in the instructions, but not on the product packaging.
The takeaway: Read the instructions carefully and check the fine print. During the hot summer months, consider storing the unit in a cool location and only taking it with you on long trips. If you are storing the unit in the car, choose a location out of direct sunlight, such as the glove box or the trunk.