MacBook Pro's battery charging only to 27%
According to this Apple Support page:


  Occasionally, the battery might not show a full charge (100%) in
  macOS, even after the power adapter has been connected for an extended
  period of time. The battery might appear to stop charging between 93
  percent and 99 percent. This behavior is normal and will help to
  prolong the overall life of the battery.


But 27% is quite low.

Additionally, you can try checking the battery cycle count. The average for your Mac is 1000.

From this article:


  Follow these steps to access information about your Mac notebook
  battery, including its cycle count:
  
  Hold the Option key and click the Apple menu. Choose System
  Information.
  
  Under the Hardware section of the System Information window, select Power. The current cycle count is listed under the Battery Information section.