I picked up one of my active basses last month that I had not touched in 3 years. I figured it would be dead and there would be powdery acid all over the battery. Nope. It still works.I just purchased a 2011 G&L Tribby L2500. When I got it, I checked the battery (it was the original it came with) AND IT STILL WORKED.
That leads me to this...the whole battery argument being a pain is WAY overblown imo. Batteries last a lot longer than people MAY want to leave them in. Add to that the multitude of basses out there now that have switches to go passive or active, it's really only an issue if you choose to let it be one.