How to choose a long-term use of USB Car Charger

Car Charger Appearance parts: 1, the appearance must be good, can not have glitches, you must insert convenient and smooth. Metal contact to be thick, uniform, elastic. Difficulties charger plug can be easily damaged. 2, the housing in line with environmental standards Rohs, hard, flame retardant. Chargers may have a fever, if the plastic shell does not meet Rohs standard, there will be gas coming out. Plastic poison is very powerful. Not hard, flame retardant plastic, will be grilled charger fever soft or even fire.

Circuit, the charger circuit is as follows: 1, resistor divider type. Car charger inside there will be a stout resistance. In this way the output voltage is unstable, and heat resistance itself is huge. In addition to cheap, I did not have any advantages other commendable. Output current can be large. No short-circuit protection, the consequences of fire or short circuit is burned cars internal circuits. 2, the regulator type, is a relatively large regulator. Can output current of 1A. More dangerous short circuit current 1A, is not a joke. It can load due to the strong ability, which is slightly higher than the 5V voltage enables faster charging. As I was looking for a line with my standard car charger when a friend 
recommended to me Ao Shuer car charger, this brand has been very well-known fact in the industry, but I WTO not deep, nor to understand too. But it is worth mentioning that this charger is not only good in appearance, very mini delicate, easy to carry, it will not hinder to my car. ABS housing is, and it is ROHS certification, these points let me very satisfied.