On a side note.. what batterys do you guys like.. I have some 2200Mha Aa but they seem to go dead in the flashlight even when used infrequently.
As others have said, Sanyo Eneloop 2000mAh AA cells paired with a Maha C9000 charger make an excellent system. Eneloops are available inexpensively at Costco.
Or if you can get the Duracell 2000 mAh "Pre-charged" rechargeable cells with the *white top*, marked "Made in Japan" -- those are Sanyo Eneloops made for Duracell.
Few things in life can be recommended almost categorically every time -- Eneloops can be.
PS: Your 2200 mAh cells are either suffering from self-discharge (normal NiMH cells suffer from this) or haven't been cared for well by whatever charger you are using. If by chance you have one of those 15 minute chargers - please chuck it out / recycle it. Those chargers are guaranteed to shorten the lifespan of *any* brand of cell.
PSPS: Regarding good lights... If your wife likes the Fenix LD20 and finds the user interface is ok (presses on the tail cap give you low-med-high-SOS / twist bezel shut for full power/strobe) then why not just pick up a Fenix LD10 R4? (
Review of the LD10 and LD20) You'll get an hour on turbo, nearly two hours on "high", off a single good quality AA rechargeable.
And if you do want to look around at other lights, good luck! There are so many great single AA lights, it can become your full time job for a while to sift through them. Our local police and fire departments outfit their members with SureFire - kinda like buying IBM long ago, you can't really go wrong with that choice. You'll be generally be looking at CR123 cells if that's the case.
PSPSPS: I disagree that a 14500 is basically an AA with a different chemistry. While strictly speaking all of that is true, we should never trivialize the safety requirements for using lithium ion cells. If you are new to the whole battery game and are enticed by the benefits of rechargeable lithium-ion cells, be sure you read up on how to look after your li-ion cells properly. They aren't "fire and forget" in any way near the same manner NiMH cells are. Li-ion can deliver great benefits but in using them you've got to be aware of the pitfalls in order to use them safely. Fortunately there is a ton of great information here on CPF and many knowledgeable folks to help you along whatever path you choose to follow.