Not just the batteries. User supplied power bricks sounds like an incredibly bad idea at pretty much any scale.
Not sure why the comment above is downvoted, but I have been twice in the same room with somebody's power brick starting producing fumes while dying.
Wait, power bricks are a fire hazard?
alt Hacker News
Not sure why the comment above is downvoted, but I have been twice in the same room with somebody's power brick starting producing fumes while dying.