iPod Classic 30gb

This is probably a question which has been asked many times but has anyone had a problem with their iPod not holding its charge? I have to charge mine almost everyday, even though it has not been used. I also keep the lock on it and it is kept in a case when not used.

I am going into hospital for a few days and want to take my iPod classic with me but don't really want to take my charger if I can help it (I have a mains charger as well as charging it from the PC)

Thanks