In regards to rechargeable 9v batteries, here is a link to rechargeable lithiums that I've been using for almost 2 years now with no problems whatsoever. It powers my Lectrosonics mics 7 hours, and recharge takes 1.5 hours. The key to this battery is don't discharge them completely or you'll kill it prematurely. I highly recommend these!

http://www.thomas-distributing.com/i...le-battery.php

As for AA, I use the Engergizer 2500mAh, for AAA the Engergizer 900mAh from Sam's Club. I'm using the AccuPower super fast charger which charges AA,AAA, and 9v NiMH batteries in about 2 hours. The AA lasts way longer than alkalines and are great!

That's a good find. I would be nervous about them if I hadn't heard a good report. I guess lithium polymer is the same as my Sony camera batteries that I generally trust. A nice bonus is that the charger is a 1.5-hour model which means that one could top off the batteries nicely during dinner or even on the road with the car adapter.

That same site has 2900mAh AA NiMH batteries. That's an impressive rating for such a small rechargeable. I guess battery technology has improved since I was last bitten by them.