C20 professional Multi-Car adaptor C20 Accurate car battery voltage display to avoid car engine start fail

This is a multi-function car adaptor, the car charger head is a power input port, there have 3 kinds of functions as below:
A: There are two cigarette lighters for cigarette lighting;
B: Input voltage display function(the voltage range is DC3.5V-30V);
C: Can charge mobile phone, PDA, MP3 etc...

Dual USB output, adjustable derection, can charge two devices at the same time;
Blue LED display when connect with the power or charging the device;
Compact design, easy to carry;
Build-in short curcuit, over charging protection function.

Car lighter gps tracker bug 2 in 1 Multifunctional Dual USB Cigar Charger 2 Port USB Adapter Quick Charger with Hide GPS Adaptor

1. Input Voltage: DC 12-24V
2. Input Current(It is the input current when using the charger, not using the cigarette lighter):
without load: 15mA MAX
With load: 1.8A MAX
3. USB output voltage:
without load: DC 5.0V-5.4V
With load: DC ≥4.75V
4. USB output current: 3100mA MAX
5. USB Output Ripple Noise: 200mV MAX
Note: USB output is 5V accoding to international standard; it can be adjusted by customer request
6. Input Protection:
There have 15A resumable safety fuse at the charger input port, when the input current is too high, the safety fuse will be melted automatically, then the power will be cut off, the charger have no output, the cigarette lighter can not be lighted up, no display for the voltage. When input current back to normal, the temperature of the resumable safety fuse will be reduce to normal, and then all above three functions will be resume to normal work.
7.Output Short Circuit Protection:
When the charger output port short curcuit, the charger will limit input and output power; when charger relieve from short curcuit, it can resume to the normal charging state automatically.