Well, I have a gun that uses battery to fire. A tesla coil, if you will.
The gun was originally intended to be too unwieldy to use by hand, but could be mounted. Back when car batteries could be charged via standard batteries it worked fine when mounted, drawing 100 charge per shot, doing minimal damage per shot, but stunning, lighting up, and bouncing off enemies.
The gun, Ive been informed, will still require batteries when mounted, due to the new turret mechanics.
Anywho, the issue may be the ups version of the gun not drawing power at all from ups.
Which is another issue entirely, but this shockcannon is incompatible with a ups conversion kit. I got around that by making an actual ups powered version, but it will not draw power from ups, making it an infinite ammo gun.