In this new battery but this is not true. My MP3 player runs for 9 hours with a fully charged battery from Sanyo with an ordinary battery 11 hours. Also chargers, which allow a long life and frequent recharging of batteries, are conveniently available today. Far from the environmental aspect and the purse is very protected. Even with the cheapest batteries you drive significantly more expensive than the battery in the long run.
In the two plastic boxes, each with four batteries are suitable four AAA batteries. The boxes are very convenient as they may be labeled with permanent marker that it is clear which batteries are empty and which is full.