what powers the slides?

I have a 2002 5th wheel Mountaineer by keystone. Just traded my TAG to get more room. Love the camper and it is in great shape. I have an electrical question that will show how little I understand the electrical system. On my TAG I always had problems with the battery being drained when I forgot to disconnect the battery or pull the inline fuse. So I had a battery disconnect switch installed on my fiver. I went to let out the slides (it was connected to 110 shore power) and I could only get the bedroom slide out. Living area slide would not move. In the storage compartment where the battery is I also have a switch which will move the slides. All I could hear was a clicking sound but the slide would not extend. After thinking about it for some time I wondered about the battery switch. Sure enough it was in the off position. Is it the battery that powers the slide? I would have thought the 110 would have done the job even if the battery was disconnected. Obviously I don't know too much about what powers what. Can someone please help me understand the system?

Thank you.