The specifications of the Phantom 4 charger says 100W, but it is printed 5,7A.  
Is it 57W ?

Power (Watts) is the product of the Current (5.7A) and the voltage (17.5v on mine) which gives a peak of 99.75 W. So yes it would be the 100W supply.

Aardvark Posted at 2017-6-1 06:46
Power (Watts) is the product of the Current (7.5A) and the voltage (17.5v on mine) which gives a peak of 131 W. So yes it would be the 100W supply.

Thanks for the info !

EmilioCid Posted at 2017-6-1 08:53
Thanks for the info !

I just amended my typo, I had written 7.5A should have been 5.7 A , which makes 99.75 Watts

I would concur with Aardvark. You may, though, just want to double check the current (A) listed.