I have read this about various things for quite a while (a long while) and it just doesn't make sense to me. I use rechargeables in everything, even some things that say not to and never had a single problem. The reason I bring this up is I was wandering around Nintendo's site (because I'm getting a Gameboy Advance for christmas) and came across this in the FAQ: "Can I use rechargeable batteries with my Game Boy? The only type of rechargeable batteries Nintendo recommends are Rayovac Renewals, but ONLY for the Game Boy Advance, Game Boy Color, Game Boy pocket, Game Boy Printer, and the built-in rumble device on Game Boy Game Paks. It is not recommended for use with the original Game Boy. Nintendo recommends against using most types of rechargeable batteries, because it's difficult to determine whether the batteries being used are all equally charged." This really makes no sense to me as I have seen plenty of Alkaline batteries die one faster than the other. The only legit concern I could possibly see is the fact that rechargeables are 1.2 volt instead of 1.5 volt. My original Gameboy and Gameboy Pocket were used with rechargeable NICD/NIMH batteries all their lives. The part that is even more strange is the fact they sell rechargeable batteries for these systems. I recently tore apart an old rechargeable battery pack for the original Gameboy and what did I find but 4 AA NICD batteries! I think these companies are full of BS. Something tells me the big battery companies pay these companies to say you can't use rechargeables as they take away from business. So anyone care to give me a valid reason why I should not use rechargeables in some devices???