[Combat Support Cell - What am I doing wrong?]

Well that's the thing, I don't see any stacks building... I can't use Supercharge Cells either, even though I definately have both skill, and they say I should be building...

 

Do you see the stacks building when you use Hammer Shot?

 

Are you sure you have the Support Cell ammo toggled on?

[Combat Support Cell - What am I doing wrong?]

Until you talent into it, Hammer Shot is the only ability that triggers stacks.

 

The second tier of talents will allow you to build stacks with Medical Probe as well.