I had the pineapple running for about 20hrs isolated from any network and the battery had not shut itself off. I've now connected it into my switch on the WAN port just to allow access to it. There's no reason the pineapple can't run off either the 5V, 9V or 12V (currently connected) outputs. Run it off the 12V and it draws less current, then run a USB device off the USB output simultaneously. I don't have a USB hub atm but will endeavor to get one in the future for testing. Of note, my pineapple isn't one from the Hakshop, I brought a Hornet-UB and flashed it myself.