It does work. TO A DEGREE. I tested in Skirmish.
It has always been a tricky proposition about getting batteries to work in SFC2. I have never really figured out the complete conditions for where and how it works. But I can tell you that they do give off power.
Two items that DEFINITELY drew power from battery in my Skirmish battle v AI are: Erratic, and Defensive Tractors.
I couldn't get Photons to draw power off batteries (I guess that's how one most easily notice the discrepancy, in the weapon systems) And I have NOT tested others races weapons.
(BTW just food for thought: Maybe Taldren implemented that "Warp power" only rule for photons?)