オリジナル投稿者： amatsuda ,
I know, it's been 7 years since you posted. But I'll still leave a suggestion. I suggest you check the battery’s condition - by going into System Information (accessible in the Other folder in Launchpad or by clicking System Report... in About This Mac, Apple logo on top left) and going to Hardware>Power. You want to pay attention to "Cycle Count" and see the number. The number should be quite low (e.g. 0-20) if it was truly new, anything like 520 something likely means it’s a used battery from another MacBook. Cycle count isn’t everything however. I had a 2008 MacBook with only 143 cycles yet the battery only held a charge for 5 minutes before dying. Turns out the replacement battery itself was crappy, so it didn’t last long at all.