A friend of mine bought a display model black Macbook from a computer store and because it was sitting out for a year continually plugged in the battery was shot. So he bought a brand new battery from the same store and everything worked fine for awhile now a scant 6 months later and after only 40 charge cycles this battery is shot too and won¹t hold any charge whatsoever and needs to be plugged in to work. He put another battery in from a friend's Macbook and it worked. He will try getting a new battery from the store but in the meantime... Would there be a problem with Macbook not charging properly or did he just get a dud battery? Are there any battery utilities people recommend? Coconut battery continually crashes on his machine and won't give any useful information. Any other suggestions? Thank you Richard