batteries question

Does all battery AA/AAA fit all flashlight that require them or certain AA/AAA fit certain flashlight?

Worldwide, all AA and AAA have the same size.

http://www.candlepowerforums.com/vb/forumdisplay.php?9-Flashlight-Electronics-Batteries-Included
http://en.wikipedia.org/wiki/AA_battery

No, most of the time (95% +) all batteries do fit but there are very few flashlights that are designed to fit alkaline batteries with little "slack" left in them such that some rechargeable AA/AAA batteries (nimh) are a tight fit. I've had a few lights that I've had to force the batteries in and one lantern that actually damaged the battery covers when I insert them they are so tight. Flashlights that recommend use of nimh batteries do fit them well. Nimh batteries are at times slightly larger in diameter than primary (disposable) batteries like alkaline and lithium ~1.5v cells.

I have a Black Diamond headlamp from about 2007. I forget which model. It takes 3 AAA, but Eneloops DO NOT fit. I think I managed to cut down the plattic with a Dremel, but the case still doesn't click shut tight. I never use this junk cool blue lamp anymore so I don't care.

Thanks guys!