I will take a contrary view, probably unpopular. I had a couple instances where I used rechargables in my original NBox which was a bit of a power hog. They were tested before the show, were AOK and crapped out in the middle of a Dylan show. End of rechargables for me. New AAAs, and the old ones go in the landfill. Sorry Woodsy. If they still have a few volts, then in the box for TV remotes and other devices until they crap out.
I will not drop a couple hundred dollars for a ticket, sometimes, an airline flight and hotel, food and stuff to lose the tape of the show. Not going to happen again, and hasn't.
All that said, I use rechargeables everywhere in my home, for the remotes, the clocks, the garage door opener, the gate security, and my handheld GPS, Beacon, and Radio I use for trail patrol. I have boxes of rechargeables, and recharge them en mass when needed. Woodsy is my friend.