Really sorry this happened to you, do you by any chance run in a different browser? Or maybe a different operating system? I'd like to investigate more if you could give me any clue? I couldnt get any crashes to happen in my own playtesting.
The mouse cursor is indeed meant to be hidden, only the mouse buttons are used!
Try looking directly at the battery with the character, and pressing "left click", it should pick up the battery.
I appreciate the time you took trying our game!