Hi i was just wondering why the battery life of an mp3 player is so poor compare to that of portable cd player or portable minidisc recorder. by this i mean the playing time. on my sony net minidisc MZN1, i can get 50 something hours from the gum stick battery supplied which is 1.5v at 1.4AhH. when i chuck a 1.5v 1.7AhH AA rechargeable i get deadly swat. i mean, mp3 players has no moving parts apart from accessing from harddrive but i don't see how that degrades the battery so much compared to my MD spining the motor round and round in circles. if anyone can come up a logical explanation, i'd appreciate that. cheers.