So, I recently came across one of these in mint green for $200 used, it is in amazing condition. I love the color and look of the thing so I am debating on grabbing it up, but I wanted to pick your brains first... This will be the first active bass I have ever owned. I have played them in the past and I do like the sound from them. I just don't really know much other than that. How often to I have to change the battery? Does it still work (passively) when the battery is dead or removed, like if it dies in the middle of a show? Should I remove the battery when I am not using it?