I just got a new 3rd G iPod. So now I have 2 iPod chargers (the boxes that plug into the wall.) They are going for $20-$40 on ebay and I don't need 2. Whats the life span on the chargers? Some of Apple's laptop chargers had problems with breaking I remember from a few years ago. If the iPod chargers crap out after awhile I won't sell the extra charger and keep it as a backup. Thanks!