Playing Steam plugged in and still lose power

Have an i7 sp4 8gb ram 256, and when I play nba 2k16 with my sp4 docked, I am few percentage points lower in battery than when I started.

Have a usb fan attached to help with heat, and play with a Bluetooth Xbox one s controller.

Anyone else?

from Windows Central Forums http://ift.tt/2hvgba1
via IFTTT