My MacBook Pro (15 in Retina, early 2013, macOS 10.14.5) sleeps unexpectedly, although there is enough charge in the battery. To wake it up, I must connect the power supply. Furthermore, the fans run at high speed every now and then, even though the MacBook isn't under heavy usage and is properly ventilated.
I reset the SMC according to these instructions: https://support.apple.com/en-us/HT201295, but the problems went on. I checked the computer with EtreCheck (core version) and coconutBattery; both detected no issues.
What else could I try?