Originally Posted by JasonCSU
How old is the Macbook? If it's a few years old, the battery may not be holding its charge as well, or it could be an issue with the SMC (system management controller). The SMC reports the battery status and should control the charging as well. There have been issues with the SMC not reporting the battery status correctly and needing to be reset. In my case, the SMC will no longer charge any battery in my Macbook even after resetting it.
Its 3 yrs old. Time for a new one.