1, the output current
The input voltage of the car charger on the market is basically 12V-24V, the output voltage is 5V, and the output current is about 1A~4A. Although most of the cars also have a USB interface, the current is only about 500 mA. When using the mobile phone to navigate, it is not enough to charge the battery. Take the iPhone 4S with a battery capacity of 1470mAh as an example. The 1A current charging can be fully charged in about 2 hours, and the time required to use the built-in USB interface in the car is basically doubled.
2, overload protection
The USB specification requires no more than 5A for current overload protection. The reason why the car charger needs overload protection is because when the output current is too large and exceeds its normal output value, the life of the charger component will be shortened or the temperature will be too high, resulting in damage or even burning. Therefore, the car charger used in the car must have overload protection measures.
3, short circuit protection
Short-circuit protection is also necessary, because once a short circuit occurs, the cigarette lighter is insured and the fire is burned. All car chargers on the market have short-circuit protection devices. However, when the short-circuit device is unplugged, some products need to be automatically powered on after the device is unplugged. Some products still do not supply power after the short-circuit device is unplugged, and need to be powered from the cigarette lighter. Pull out and reinsert it to continue powering. Of course, it is more convenient for the owner to automatically restore the power supply.
4, LED lights
The car chargers on the market are equipped with LED nightlights to facilitate location confirmation when driving at night. However, the brightness of LED lights should be noted, because driving during the day does not have any effect, but if it is too bright at night, it may distract the driver's attention and affect driving safety. Generally speaking, the LED brightness can see the USB interface. The location is not glaring.
5. Does it cost electricity after the flameout?
Although 80% of the vehicles are powered by the cigarette lighter after the vehicle is unplugged, some of the car's cigarette lighters are continuously powered. In case the owner forgets to unplug the car charger, will there be any damage to the vehicle battery? Generally speaking, the car charger has no current output when the load is not connected. Even if you forget to unplug it, only a small LED light is working, and the lost battery power is negligible.
When you choose, you should still pay attention to it. Don't just look at the brand and don't look at the product. It is the best for you.