I dont know alot about macbooks but I am just lost in the sauce about this issue. I bought a macbook and the guy I bought it from told me it had a bad battery. So I bought the new battery and it still gives me the no batteries availiable problem where the battery symbol is. When I got the battery I pressed the button and it was charged more than halfway. I even unplugged it and left it unplugged for a while but it still said no batteries availiable. I eventually drained the battery (according to the back of the battery) trying to get it to work. So it doesnt charge what so ever or anything. I can only use it plugged in. I can unplug it for about 20 seconds before it shuts off. I am not sure what the issue is. I have done smc resets. pmu resets and a bunch of other stuff I have read online so I figured I would come here and see what you guys say. I have used a different charger. I would say it was a bad battery but it obviously is a good battery sincing it was charged up when I got it and the fact that the macbook was left unplugged for over a hour and it was fine.