I use car chargers every day. I have Samsung Galaxy 3 phones, and until recently had a charger purchased from Verizon when I got the phone 2 years ago. It was a dual charger with USB port, which I used for my Tom Tom. On a recent trip, suddenly I saw that the charger was not charging my phone. When I got home, I purchased a similar charger from Walmart, which seemed to work only intermittently for a few days and then not at all. I noticed that the charger itself was hot. Also I tried the charger in other outlets in my car with similar results. Soooo, I ordered a new charger off Amazon. It was exactly like the first charger which had worked for 2 years and even had the Verizon brand. I plugged it in and the phone immediately started to charge. However, the next day was a different story. Plugged it in, nothing happened. Then after a minute I heard the beep but there was a red X on the battery icon. It did charge but was hot again. Then when I went to unplug the phone, accidentally twisted the cord a little and saw that the end of the cord next to the phone was melted!!! My phone is charging normally in every other charger I use. I think this must have to do with my car's electrical system.