Hm, now that you mention it I hadn't realized you could leave the energy on the board and select between weapons before picking it up. I think the battery approach might prove a bit more intuitive though, but we'll have to see. Something else to consider if you like, instead of clicking the weapon to draw power from the battery, consider setting it up like an action queue system. What I mean by this is, you can select/toggle multiple weapons "on" at a time, and then press the battery button to send the energy to all of them at once. This way you can use multiple weapons simultaneously in a given action.
Viewing post in Looking for feedback, minesweeper in space
Np, seems like a fun little prototype. Be interesting to see what its like if you ever decide to flesh it out, seems like a lot of little details could be put in, like a more CR-8 style inventory for ship systems, hull/power/shields/weapons/etc.