Maybe it is. When I use 150w power inverter to charge phone in car, the light of the inverter is red, when you end charging, the light is green. The way for me to use this inverter is to connect it with car cigarette lighter charger outlet. You can charge laptop, camera battery and shaver with this power inverter in the same way. If you need to know more details about this charger, you can search bestekmall on Google. Have a nice day.