Disclaimer: I dont know where this should go by general consensus, its a grey area, so feel free to move it. That said, I'm making a boom bag out of an old satchel and a couple of old computer speakers. I've already removed the speakers and the circuit board from thier casings and have successfully enabled them to work on batteries. The normal input from the wall adapter is 15 V at 800 MA DC. I've got two 6V Flashlight batteries but its been a while since I took electronics. I need to know whether to wire them in series or parallel. I think i remember putting them in series will produce 12 V which would be great, more volume, but I might be willing to reduce the voltage if it would mean better battery life. Also, I'd like to know if theres a better way to connect the batteries to the circuit board than a couple of bullet terminals. I'd like to find some way of splicing them into the wall adapter without fear of having the current pass through the batteries thus turning my backpack into a bomb. They look down on carrying explosive devices around campus. Even ones you have to plug in. Any help is appreciated, thank you.