If they are the red Efest 2000 mah batteries, they are only 10 amps CDR per battery. For your Segelei 150, you'll need at least 20 amps CDR, preferably 30 amps CDR.
Battery Basics for Mods <---- contains a listing of recommended 18650 batteries with specifications
I recommend Sony Vtc4 18650 2100 mah 30 amp CDR batteries.
You can find them here.
Have you read the instructions manual or watched a review/demo of the Segelei 150 on YouTube? How many button presses to "turn on" the mod?